Jeez, this video is long. Loved it. ;) I feel compelled to do the same thing on the Eagle version, though, so it can be re-uploaded on github more easily. Could you have just changed the grid snap on this before starting, or was there a reason? Really annoying when people make schematic symbols for Eagle that aren't on the standard grid. That's way worse. lol
i hate googling a schematic and seeing them all in google images, most of them are posts to forums trying to trouble shoot them because they arent working, gotta be very careful you dont use them for reference.
Dave, can you do a PCB version of this video? With proper industry standards and usual conventions! These type of videos are really helpful for students like me. Thanks, Dave!
Don't know why he even chose this project. Altium offers so many built-in features that greatly help in themselves to create better readable schematics.
Dave Thanks for the video. Back when I was in a 2 year ET course in the '70's we had a course called "Blueprint Reading and Sketching" which was an obsolete name even then for a mechanical drawing/drafting class. It is amazing how we went from drawing tube circuits by hand to using CAD schematic software to draw the connections to Integrated circuits. But the basics remain the same; signal paths go left to right, Input voltages connections point up, ground connections points down, label everything neatly and clearly but most of all be consistent across the drawing.
This is a great intro for people like me who are just starting to design electronics. It's like a whole chapter in a textbook on electronics design in an hour or so long video with examples and advice laden throughout. Thanks a lot, huge fan of the channel.
I was never taught this stuff, but you naturally pick it up from looking at other people schematics. It's like reading a book, it just makes sense to do it this way.
Not only the newer one is easier to read, but also very modular, like properly structured code. The engineering part is indeed shared between software and hardware.
There was an amazing amount of good information in this video for those of us who are teaching ourselves. Information not only on making, but on reading schematics. I watched it once, and will probably return to watch it, again. Thank you!
Around 4:00 I always hated that touching but not connected possibility in Eagle, shocked it's also in the expensive Altium. This kind of misapplication of mechanical drawing concepts to the schematic editor is just wrong. Schematics are logical, not mechanical and the exact placement of lines is formatting, not data. Either draw wires as connected or automatically show a clear distance of one grid step, especially if overlapping / touching lines would otherwise result from an editing operation such as moving or copying.
I also found that was a bit weird it would do that, whereas EasyEDA which is web based on the other hand does, it may not have some of the more advanced features pros use but for a newbie such as myself it's far easier and more intuitive than some of the other tools I've tried or just watched others use, I was able to make my first schematic using it without having to look up some tutorial on how to do most things.
It is obvious that Dave is familiar with a particular program. He has taken his time to learn what he is using. If you are "expert" with another program, feel free to use that one. You can make mistakes or artistry in just about any program.
(Happy) long-time Eagle user here. Eagle ERC will warn you most of the time if you make that mistake, ie. you have nets/pins close not actually connected. Also it is visually possible to see if the connection is made or not, as there is a dot of a third colour used where the connected net and pin meet. It would be better (particularly for folks with colour perception difficulties - not rare!) if it were more than a colour difference. Maybe a smaller version of a junction dot?
Actually this problem should never happen if you keep the schematic grid on the standard 1.27 (that is mm) and never touch the alt key, also if you make new parts you never change the grid options on the schematic side. I believe this is noted on the official tutorial or somewhere like that. The recent versions have fixed this being giving a nice positive feedback (a circle on the pin when the connection has happened). All the grid settings that Dave is mentioning are not needed on Eagle.
Only time it really bothered me in Eagle is when you move or paste a block including wires, put it down somewhere so that your moved wire drops onto the pin of an existing device and it doesn't connect them, you have to lift the unmoved part and drop it again to connect them. There is no visual difference between connected and unconnected if it isn't a junction and everything I described stayed on the same grid.
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Excellent, that this comes up for discussion! When we developed the first stepper motor controller with PC GUI in 1994, I knew that good readability of electronic schematics will be very important.
excellent video, its very helpful to learn tips from a pro like this, since often books and tutorials don't explain minor details and real-world conventions, its often taken for granted that you already know such things.
Very informative. This kind of hands on practical information is pure gold for a newly graduated electrical engineer such as myself. Thanks a lot Dave!
Electrician here, not electronicist, but I'll put my $0.02 on the 'multiple sheets' ledger. I regularly fault find machines with 40+ sheets in their schematics, often with one physical component of the machine (i.e. a VFD or PLC I/O card) per sheet. Providing the inter-sheet labels are done properly, it's easier flipping through a booklet than trying to manhandle an A1 page around.
It all depends on the circumstances. for a student project i helped a friend to redesign a board (1 out of 6 for a robot). it had 1 shematic per board and that worked rather well - just the board we did was the main-controller and connected everything: it had the power-supply, charging, logic, debug-connectors, sensors, connectors to other boards and so on. And the previous design had all that cramped onto one sheet. We split it up so that the control+sensory parts were on one sheet, power-delivery on another, and extra-connectors and debug-stuff on a 3rd page. Having status-LEDs and debug-connectors all one the same page as your sensors doesn't really help.
I loves me a good ladder diagram. We had some German ones that were 4m long. Preferred the A1 sheets we had at a Freezing works I did some of my apprenticeship at, you had space to modify with pen and ruler, no CAD back then.
A0 for the full square metre! 😎 I got to 16 A4 sheets once. Moderately complex machine controller. I do like the concept of definable circuit function blocks to describe identical circuit blocks with only inputs and outputs as variables. Draw once, reuse N times. Schematic ought to fit onto three A3 sheets using existing symbols. Or four A4 sheets from scratch.
I'll agree, multiple sheets for anything more than a simple diagram. Also, in Eagle at least, new sheet and immediately drop a frame. First thing every time.
For machines with their multiple components which each have several boards, yes that is the way to go. But splitting signal paths onto several pages when it is all on one board is a pain in the ass.
Take 5 more every time he talks about a grid that isn't shown, as if we magically know where the invisible grid is in the most overpriced program available.
Dave, after a lifetime of working with electronics, it`s a real pleasure to watch you point out all the bullshit in that schematic. It can be really frustrating, confusing and very time consuming to grasp the functionality of poorly drawn circuits. Thanks
Surely, one of the best videos explaining how to draw good schematics. This messy one reminds me of one device I had to fix back then... Relatively straightforward control unit with bunch of relays, rs485 transceivers and opto-isolated inputs, but... Whole schematic was drawn in "squares" of buses with ALL nets possible tied to it. And no, there was no exception for power rails @_@ Another + for mentioning multiple sheets. You really want to draw it this way, especially for highly expandable devices or with many production variants.
I love this video.....I never stop looking for ways to improve my schematic readability. I will say that I use (along with others) diagonal lines to depict Kelvin connections on sense resistors. Serves the purpose of communicating the difference between a regular resistor and a current sense with very specific layout requirments.
Dave, thank you for this video. I am self taught and the original schematic sent my OCD into overdrive! I would say that I naturally did about 80% of what you said but I really like the flow and showing blocks. I have had to design most of the parts myself and so far I have done them in leg positions but inputs on the left and outputs on the right is going to be my new standard. Brilliant.
Thanks Dave. My mechanical engineering drafting skills concur with your fixer upper. I remember the old drafting machines and pencil. I am thankful for the great leap forward to CAD. I too enjoy simple layout with consistency.
This was a really useful video. Thank you. I layed out my first PCB, prior to watching this, I was happy to see that I intuitively followed much of the advice and I was not too far off. My circuit was much less complex but did not make many of the mistakes that you corrected in this. I also think this was a win for open source. While this guy probably was a little upset, he probably learned quite a lot and so did I!
Dave, I'm glad you addressed this issue. I'm sure there are MANY "designers" who don't know/care about the importance of this subject. This schematic is evidence of someone who's only priorities were getting everything connected so he could throw the problem over the wall to the pcb layout person and meeting the pressure from the clock. Readability by any of the other "customers" of the system (QA, tech writer, manufacturing engineers, etc) just were not a consideration. BTW: In the last company I worked for the drafting department was staffed by people who when asked "What about DRC's" responded with "Huh? What's that?" I shit you not.
1:05:15 In that case a 45° crossover is suitable to indicate the symmetry here. The eye catches that easily and interprets it as a swap of the signals. It's like drawing flipflops.
That cleaned up nicely! A lot of the schematics unwritten conventions in this video resonates with my experience from doing electronic engineering in a company making IT components back in 2008. I learned from my colleges, where a revision on the pcb was not just a number, but an actual schematic review meeting with my colleges where they asked me all sorts of question related to the circuit. It was there I learned the importance of readability of the circuit. Lately I've seen in kicad that the symbol library has started hiding power pins. As someone working with netlist and verifying layout done by external company, that would be a huge pain.
Very nice video -- spot on. With any CAD package it's important to learn the package design flow process first. I have used all sorts of tools starting from drafting board and "T" squares, currently use DipTrace. I don't do large designs any more so I have settled on designing with an A3 sheet and printing on A2 -- gives nice readability on the printout -- use extra sheets if it doesn't fit. Do a lot of wiring using "connect by NET NAME" without running long graphic net lines. First start out by blocking out the design on paper, and as Dave indicated, flow is left to right. Next decide on all the parts, and locate them in the tool library. Place an example of each part on a temporary schematic page to verify they all work and are what you want. For parts not in the library or ones that don't fit your desired flow build the new part models. Also verify they have the appropriate footprint for the PCB. If you do these step first the schematic will be easy. Generally I give all nets descriptive names except for short pin to pin nets that are not likely to need debugging. Don't make the schematic too busy and add lots of notes -- you will appreciate them later. One last advice (at least with DipTrace) watch you grid settings if you use different grid settings all over the place you will be hosed up. One more: NEVER 100% trust the CAD vendor's library ---Always verifiy.
Thanks Dave for setting the record straight. This video becomes compulsory 101 homework for students.... I have had it up to the gills over some of the downright wrongly laid out schematics i am expected to comprehend not only for various Maker Projects but creeping into the odd actual product support manuals. For some reason too there seems to be a culture of how dare you correct me...
Seriously! This vid was a lot more interesting than I thought when I start watching it, don't take it wrong I do like all your vids. But Now it seems like I have to redraw my latest schematic... Thanks, Dave.
I like that you did this after the review in the Mailbag. Not just saying "it's shit, you suck" like many people would, but showing how it's done. Thank you :)
I watched till 46min and than skipped to the end, to check, and I think you still have 100nF as AC coupling cap instead of the 10nF/0.01uF I will watched all of this later, because I think this is even more educational as your other layout/schematic videos, because here you have to explain every single step you do, and its a lot you do... I learned a lot, even my frist layouts weren't that messy...and not that complex ;) Edit: So I see, I won't be uploaded, but still amazing "work". Very informative
Oddly, I did all this by instinct at 15 years old at home for nobody to see but me -- because it makes it so much easier to read and troubleshoot etc.. Glad to see others being taught the right way to do these things from the start. Also, I might add that the person creating this schematic may not read from left top to right bottom or know English as the first language. It doesn't excuse 80% of the issues here, but just saying there are other conventions than left-top, right-bottom. Having said that, the sideways or upside-down gnds and lines across the parts is just inexcusable in any language.
I cant remember how old sagan is now ( is he about 8 now?) but he could instinctively draw a better schematic than this. I wouldnt call this a dogs breakfast because that is insulting to dogs. they eat better than this.
To whomever designed this schematic -- you did a lot better than I did on my first couple dozen or so schematics. No shame. We all start from somewhere.
This is great info, learned a LOT. Just recently finished my first very simple layout - now I have some work to do it right. Especially liked how the verbose ROFFSET1 goes into OFFSET4 line and so on...
For connecting power to the connectors, I cross the signals to connect like you do at 1:06:13; I find it still very easy to read. A lot of the time you'll have several ground/power connections on the connector, so you can just "tap off of it".
If you layout schematics, please watch the whole video. You will save many a person's headaches. This is a VERY informative video. Well worth watching the whole thing. Thanks! P.S. Even if you draw small schematics on a piece of paper ("Dave Cad") the conventions Dave mentions are VERY useful to follow. You need to show both the "bad" and "good" to explain the difference.
Schematics are much like stories in literature. There are good ones that are easy to follow, and difficult ones. Dave did a marvelous job of transforming here.
In view of the size of this schematic, I would have started from scratch altogether. It would have taken less time. Great tutorial Dave. Thanks for posting.
Avoiding 4-way junction is still good advice even if you do not use a photocopier. The connection dot may disappear when you zooming out or when scaling down schematic picture, but it all depends on what program you use.
The benefits of being the head cook and bottle washer is you get to use the CAD software schematic to highlight pins and nets on the PCBs layout...I HATE searching for pins to probe. Btw: Good tutorial mate!
Hmm. I use what you'd call "redundant net names" so that the net names during PCB layout aren't just random cryptic auto-generated names. I find this helpful during layout, as I'm not left trying to guess what each resistor is actually doing.
I stared my career as a technician, first in the military (with mil-spec schematics), then in industry while putting myself through university toward my degree in computer engineering (digital half of EE plus all of CS). Even though I'm primarily a software engineer, I'm screaming death in hardware design review meetings, as I feel I must support the technicians who will eventually have to work on the product and the software folks who'll program it. A good schematic greatly facilitates the work of the entire product team. Schematics are a representational language, with a syntax and semantics that, when properly used, will support clear communication, not just as static documentation, but also as a functional tool across multiple domains.
I work as a lab mechanic and these days I'd be happy getting any schematic - most equipment manufacturers are not providing them to their customers anymore. But still a great video!
I never tought it is possible to create a schematic like this with Eagle. I would have to scratch my head for a long time if I would like to do it intentionally. Amazing! (especially the rotating labels on the nets)
1:07:13 Maybe it's the practice/rule of thumb of using an electrolytic and ceramic capacitor in parallel for optimum frequency response (they may be different kinds of caps?).
I was so happy to see the improvements, I almost giggled when the second stage of inputs was sorted and placed in a block. I guess that makes me above average nerdy. (At least compared to the general public, not necessarily with the rest of the EEVblog audience) I can live with that.
Mistakes: 1. USB output on the right! 2. Keep pinout labels at connectors to tell people which pin does what. 3. Keep symbols reusable, so an FPGA or ADC should have logical, not design specific symbols (though the ones here are bad).
1. Unused net naming required if declaring net classes by harness otherwise unused pins will lack correct electrical constraints 2. Package of the component is essential information of for ex. decoupling cap frequency behavior (10nF 0402 vs 1206) - not clutter! Do not hide it to the bom only or you will end up mistakes not noticed! Same for voltage rating, dielectric, ... build the library so that all operation related essential information of components is visible! 3. Build the library to follow strict graphical guidelinen - no manual adjusting should be needed 4. USE COLORS - red/green for power/ground etc. - much more readable! 5. Generate the components not just yellow boxes - include operational information to clarify what the component is doing. And visualize - green leds are green - not ”B3632f-G”
I disagree about colour coding, i think. I don't want my schematic looking like a christmas present wrapping paper. Also, it makes it impractical when printed in black and white. I think it would be better to solve it logically in a different way. I think.
At 1:12:20 it looks like four bits got reversed by reordering the labels. I don’t see why it couldn’t be used by the project people. It seems there should be no reason not to send it back.
For the 0 v line, the ground symbol is used. I have seen schematics where they used the symbol for the + voltage connector, but downwards. And i have the impression he also used a polarised capacitor symbol on places with a non-polarised capacitor.
Sometimes I do have ground symbols pointing upwards, especially when dealing with negative supply voltages. I like to have the parts arranged vertically like the voltages distribute in the circuit.
I don't like connecting pins with net names. If you make a typo on the names you don't have a connection. I always use either a direct connection using lines or busses, or an off page connector. Then you can add the Intersheet reference on the port and know it's connected.
7:10 .. one "exception" .. If I have "kind" of an differential pair and want to clearly show that it changes polarity, I draw it like this "=x=" between source and sink. Did that on an ECL circuit one, for example.
I've never had a problem with upside down ground symbols; they're just symbols, not arrows. They look silly if you have to hair-pin bend them or make them cross other nets just to make the symbol point down. And if you have negative voltage rails near the bottom of the page then it makes even less sense to make the ground symbols (higher up the page) point down.
A bit late, but I was just finishing up a schematic of mine and saw this old video in the recommended list. For the big yellow rectangles framing in the different stages, I would pick a more pale yellow, like Altiums color number 214, so all the yellow parts stand out more. :)
Please do NOT complain or comment about the length of this video. I know. It is what it is.
Complain... why would they? It saves them time, why watch 3 or 4 videos when you can watch 1.
Waaaaaay too long... jk
No complaints here. I might have used two sheets for it though.
I prefer longer format videos. Makes great background noise
Jeez, this video is long.
Loved it. ;)
I feel compelled to do the same thing on the Eagle version, though, so it can be re-uploaded on github more easily.
Could you have just changed the grid snap on this before starting, or was there a reason?
Really annoying when people make schematic symbols for Eagle that aren't on the standard grid. That's way worse. lol
Of course the labels were upside down, you are in the southern hemisphere. I also hear that electrons flow the other way down under.
I wonder if there is an Eagle function to randomly select the orientation for each label....
I believe they might use positrons as all the electrons fall out the bottom.
No problem. You ground to the sky.
author was right in the equator thats why half the power and grounds were flipped
Not quite - everything's upside down. so the electrons all fall out.
A longer vid means more information to me
thanks Dave
on Dave's channels, yes!
Dave Jones Locker is up side down ! Flip your screen to read the original schematic properly.
This video needed to be made. The maker movements is great but led to so many pile-of-mess schematics floating around on the web.
Except I think he already went over all of this with the uSupply.
Along with dogs breakfast code
Kosmonooit dog’s*
i hate googling a schematic and seeing them all in google images, most of them are posts to forums trying to trouble shoot them because they arent working, gotta be very careful you dont use them for reference.
Even some of the arduino schematics suckkk ass
Dave, can you do a PCB version of this video? With proper industry standards and usual conventions! These type of videos are really helpful for students like me. Thanks, Dave!
I agree, we definitely need a PCB layout video.
Don't know why he even chose this project. Altium offers so many built-in features that greatly help in themselves to create better readable schematics.
yes we need one, mankind needs one
Dave Thanks for the video. Back when I was in a 2 year ET course in the '70's we had a course called "Blueprint Reading and Sketching" which was an obsolete name even then for a mechanical drawing/drafting class. It is amazing how we went from drawing tube circuits by hand to using CAD schematic software to draw the connections to Integrated circuits. But the basics remain the same; signal paths go left to right, Input voltages connections point up, ground connections points down, label everything neatly and clearly but most of all be consistent across the drawing.
This is an excellent tutorial on schematic drawing conventions. They never teach this stuff in college. 100 thumbs up.
This is a great intro for people like me who are just starting to design electronics. It's like a whole chapter in a textbook on electronics design in an hour or so long video with examples and advice laden throughout. Thanks a lot, huge fan of the channel.
I was never taught this stuff, but you naturally pick it up from looking at other people schematics. It's like reading a book, it just makes sense to do it this way.
Not only the newer one is easier to read, but also very modular, like properly structured code.
The engineering part is indeed shared between software and hardware.
That original schematic seriously has to have been a "prank" to elicit a response from Dave.
Even sagan could draw a better schematic than that.
There was an amazing amount of good information in this video for those of us who are teaching ourselves. Information not only on making, but on reading schematics. I watched it once, and will probably return to watch it, again. Thank you!
This video is much appreciated. It is good to hear from someone who has a lot of experience give instructions on how to draw a schematic.
Around 4:00 I always hated that touching but not connected possibility in Eagle, shocked it's also in the expensive Altium. This kind of misapplication of mechanical drawing concepts to the schematic editor is just wrong. Schematics are logical, not mechanical and the exact placement of lines is formatting, not data. Either draw wires as connected or automatically show a clear distance of one grid step, especially if overlapping / touching lines would otherwise result from an editing operation such as moving or copying.
I also found that was a bit weird it would do that, whereas EasyEDA which is web based on the other hand does, it may not have some of the more advanced features pros use but for a newbie such as myself it's far easier and more intuitive than some of the other tools I've tried or just watched others use, I was able to make my first schematic using it without having to look up some tutorial on how to do most things.
It is obvious that Dave is familiar with a particular program. He has taken his time to learn what he is using. If you are "expert" with another program, feel free to use that one. You can make mistakes or artistry in just about any program.
(Happy) long-time Eagle user here. Eagle ERC will warn you most of the time if you make that mistake, ie. you have nets/pins close not actually connected. Also it is visually possible to see if the connection is made or not, as there is a dot of a third colour used where the connected net and pin meet. It would be better (particularly for folks with colour perception difficulties - not rare!) if it were more than a colour difference. Maybe a smaller version of a junction dot?
Actually this problem should never happen if you keep the schematic grid on the standard 1.27 (that is mm) and never touch the alt key, also if you make new parts you never change the grid options on the schematic side. I believe this is noted on the official tutorial or somewhere like that. The recent versions have fixed this being giving a nice positive feedback (a circle on the pin when the connection has happened). All the grid settings that Dave is mentioning are not needed on Eagle.
Only time it really bothered me in Eagle is when you move or paste a block including wires, put it down somewhere so that your moved wire drops onto the pin of an existing device and it doesn't connect them, you have to lift the unmoved part and drop it again to connect them. There is no visual difference between connected and unconnected if it isn't a junction and everything I described stayed on the same grid.
Excellent, that this comes up for discussion! When we developed the first stepper motor controller with PC GUI in 1994, I knew that good readability of electronic schematics will be very important.
excellent video, its very helpful to learn tips from a pro like this, since often books and tutorials don't explain minor details and real-world conventions, its often taken for granted that you already know such things.
Very informative. This kind of hands on practical information is pure gold for a newly graduated electrical engineer such as myself. Thanks a lot Dave!
fantastic! ......there is simply no substitute for a veteran in the industry to show you how its done!
Electrician here, not electronicist, but I'll put my $0.02 on the 'multiple sheets' ledger. I regularly fault find machines with 40+ sheets in their schematics, often with one physical component of the machine (i.e. a VFD or PLC I/O card) per sheet. Providing the inter-sheet labels are done properly, it's easier flipping through a booklet than trying to manhandle an A1 page around.
It all depends on the circumstances.
for a student project i helped a friend to redesign a board (1 out of 6 for a robot). it had 1 shematic per board and that worked rather well - just the board we did was the main-controller and connected everything: it had the power-supply, charging, logic, debug-connectors, sensors, connectors to other boards and so on. And the previous design had all that cramped onto one sheet.
We split it up so that the control+sensory parts were on one sheet, power-delivery on another, and extra-connectors and debug-stuff on a 3rd page.
Having status-LEDs and debug-connectors all one the same page as your sensors doesn't really help.
I loves me a good ladder diagram. We had some German ones that were 4m long. Preferred the A1 sheets we had at a Freezing works I did some of my apprenticeship at, you had space to modify with pen and ruler, no CAD back then.
A0 for the full square metre! 😎
I got to 16 A4 sheets once. Moderately complex machine controller.
I do like the concept of definable circuit function blocks to describe identical circuit blocks with only inputs and outputs as variables. Draw once, reuse N times.
Schematic ought to fit onto three A3 sheets using existing symbols. Or four A4 sheets from scratch.
I'll agree, multiple sheets for anything more than a simple diagram.
Also, in Eagle at least, new sheet and immediately drop a frame. First thing every time.
For machines with their multiple components which each have several boards, yes that is the way to go. But splitting signal paths onto several pages when it is all on one board is a pain in the ass.
I'm proud and happy that channels like this one exist on RUclips
Take a drink every time Dave complains about the lack of grid alignment
u wud be shitfaced in 10 minutes
well to be honest that is one of the greatest PITAs you can possibly do.
Take 5 more every time he talks about a grid that isn't shown, as if we magically know where the invisible grid is in the most overpriced program available.
Dave, after a lifetime of working with electronics, it`s a real pleasure to watch you point out all the bullshit in that schematic. It can be really frustrating, confusing and very time consuming to grasp the functionality of poorly drawn circuits. Thanks
This should be required viewing to all beginner EE students
Thanks! My mentor recommended this video to me and suggested I follow your tips. This vid is really helpful in making my schematic better.
10:40 - Chip pin-outs with pins in physical order are for WIRING DIAGRAMS, not schematics!
Thank-you for making. It's incredible what goes for a schematic now days.
Thanks Dave. I watched the video end to end and enjoyed it. I learned a lot too. Best wishes.
6:50 - The grounds are upside-down? Is this an Aussie schematic, by chance? :)
Surely, one of the best videos explaining how to draw good schematics.
This messy one reminds me of one device I had to fix back then... Relatively straightforward control unit with bunch of relays, rs485 transceivers and opto-isolated inputs, but... Whole schematic was drawn in "squares" of buses with ALL nets possible tied to it. And no, there was no exception for power rails @_@
Another + for mentioning multiple sheets. You really want to draw it this way, especially for highly expandable devices or with many production variants.
Thank you Dave. This is the best schematic creation video on youtube. I learned a lot.
I love this video.....I never stop looking for ways to improve my schematic readability.
I will say that I use (along with others) diagonal lines to depict Kelvin connections on sense resistors. Serves the purpose of communicating the difference between a regular resistor and a current sense with very specific layout requirments.
Diagonal lines can also emphasize other things, like conceptually swapping two signal lines.
Dave, thank you for this video. I am self taught and the original schematic sent my OCD into overdrive! I would say that I naturally did about 80% of what you said but I really like the flow and showing blocks. I have had to design most of the parts myself and so far I have done them in leg positions but inputs on the left and outputs on the right is going to be my new standard. Brilliant.
Thanks Dave. My mechanical engineering drafting skills concur with your fixer upper. I remember the old drafting machines and pencil. I am thankful for the great leap forward to CAD. I too enjoy simple layout with consistency.
This was a really useful video. Thank you. I layed out my first PCB, prior to watching this, I was happy to see that I intuitively followed much of the advice and I was not too far off. My circuit was much less complex but did not make many of the mistakes that you corrected in this. I also think this was a win for open source. While this guy probably was a little upset, he probably learned quite a lot and so did I!
Dave, I'm glad you addressed this issue. I'm sure there are MANY "designers" who don't know/care about the importance of this subject. This schematic is evidence of someone who's only priorities were getting everything connected so he could throw the problem over the wall to the pcb layout person and meeting the pressure from the clock. Readability by any of the other "customers" of the system (QA, tech writer, manufacturing engineers, etc) just were not a consideration.
BTW: In the last company I worked for the drafting department was staffed by people who when asked "What about DRC's" responded with "Huh? What's that?" I shit you not.
1:05:15 In that case a 45° crossover is suitable to indicate the symmetry here. The eye catches that easily and interprets it as a swap of the signals. It's like drawing flipflops.
That cleaned up nicely! A lot of the schematics unwritten conventions in this video resonates with my experience from doing electronic engineering in a company making IT components back in 2008. I learned from my colleges, where a revision on the pcb was not just a number, but an actual schematic review meeting with my colleges where they asked me all sorts of question related to the circuit. It was there I learned the importance of readability of the circuit. Lately I've seen in kicad that the symbol library has started hiding power pins. As someone working with netlist and verifying layout done by external company, that would be a huge pain.
Just realised this video is 3 years old. Haha. RUclips recommended this to me. It must be a sign :D
Very nice video -- spot on.
With any CAD package it's important to learn the package design flow process first. I have used all sorts of tools starting from drafting board and "T" squares, currently use DipTrace. I don't do large designs any more so I have settled on designing with an A3 sheet and printing on A2 -- gives nice readability on the printout -- use extra sheets if it doesn't fit. Do a lot of wiring using "connect by NET NAME" without running long graphic net lines. First start out by blocking out the design on paper, and as Dave indicated, flow is left to right. Next decide on all the parts, and locate them in the tool library. Place an example of each part on a temporary schematic page to verify they all work and are what you want. For parts not in the library or ones that don't fit your desired flow build the new part models. Also verify they have the appropriate footprint for the PCB. If you do these step first the schematic will be easy. Generally I give all nets descriptive names except for short pin to pin nets that are not likely to need debugging. Don't make the schematic too busy and add lots of notes -- you will appreciate them later. One last advice (at least with DipTrace) watch you grid settings if you use different grid settings all over the place you will be hosed up. One more: NEVER 100% trust the CAD vendor's library ---Always verifiy.
Robert Feranec's course material is all you need, no whining pure facts.
Thanks Dave for setting the record straight. This video becomes compulsory 101 homework for students.... I have had it up to the gills over some of the downright wrongly laid out schematics i am expected to comprehend not only for various Maker Projects but creeping into the odd actual product support manuals. For some reason too there seems to be a culture of how dare you correct me...
Seriously! This vid was a lot more interesting than I thought when I start watching it, don't take it wrong I do like all your vids.
But Now it seems like I have to redraw my latest schematic... Thanks, Dave.
I like that you did this after the review in the Mailbag. Not just saying "it's shit, you suck" like many people would, but showing how it's done. Thank you :)
Great video! Some of these blocks would very much lend themselves towards hierarchal implementations (especially the repeated ones)
I watched till 46min and than skipped to the end, to check, and I think you still have 100nF as AC coupling cap instead of the 10nF/0.01uF
I will watched all of this later, because I think this is even more educational as your other layout/schematic videos, because here you have to explain every single step you do, and its a lot you do...
I learned a lot, even my frist layouts weren't that messy...and not that complex ;)
Edit: So I see, I won't be uploaded, but still amazing "work". Very informative
Oddly, I did all this by instinct at 15 years old at home for nobody to see but me -- because it makes it so much easier to read and troubleshoot etc.. Glad to see others being taught the right way to do these things from the start. Also, I might add that the person creating this schematic may not read from left top to right bottom or know English as the first language. It doesn't excuse 80% of the issues here, but just saying there are other conventions than left-top, right-bottom. Having said that, the sideways or upside-down gnds and lines across the parts is just inexcusable in any language.
I cant remember how old sagan is now ( is he about 8 now?) but he could instinctively draw a better schematic than this. I wouldnt call this a dogs breakfast because that is insulting to dogs. they eat better than this.
To whomever designed this schematic -- you did a lot better than I did on my first couple dozen or so schematics. No shame. We all start from somewhere.
Great video, a skill every Electrical Engineer should have before they leave school and sadly do not.
HEY DAVE! Good video I would rather watch one long video than watch multiple shorter videos. Thanks for all your hard work.
This is great info, learned a LOT. Just recently finished my first very simple layout - now I have some work to do it right. Especially liked how the verbose ROFFSET1 goes into OFFSET4 line and so on...
I am going through ee school. This was great for explaining convention and pit falls before I even thought of them. Thanks
don't have stuff flapping around in the breeze :-) fantastic, I love the way you explain this
This is very helpful for a rank amateur like me. Thanks, Dave!
i love how dave starts off by fixing every mistake but slowly loses patience with it
For connecting power to the connectors, I cross the signals to connect like you do at 1:06:13; I find it still very easy to read. A lot of the time you'll have several ground/power connections on the connector, so you can just "tap off of it".
No worries about video lengths! Just keep a good mix of shorter and longer vids (but I do not really need to tell you that)... Nice job, Dave!
If you layout schematics, please watch the whole video. You will save many a person's headaches. This is a VERY informative video. Well worth watching the whole thing. Thanks! P.S. Even if you draw small schematics on a piece of paper ("Dave Cad") the conventions Dave mentions are VERY useful to follow. You need to show both the "bad" and "good" to explain the difference.
Yeah the view count is surprisingly low on this video.
Schematics are much like stories in literature. There are good ones that are easy to follow, and difficult ones. Dave did a marvelous job of transforming here.
A useful video with lots of convention stuff I had no idea about. Thanks!
In view of the size of this schematic, I would have started from scratch altogether. It would have taken less time. Great tutorial Dave. Thanks for posting.
Great video I'm studying electrical engineering and I learn a lot. I hope there is a video about best practices in PCBs
Good food for thought. Definitely going to take this in account when I make schematics in the future!
Amazing, useful video - many thanks. Good to know I mostly do things correctly - and picked up some very useful tips too.
DaveScope Kickstarter? :)
Thank you Sir I was just searching for how to do the schematic, I definitely understood what you explained!
Avoiding 4-way junction is still good advice even if you do not use a photocopier. The connection dot may disappear when you zooming out or when scaling down schematic picture, but it all depends on what program you use.
This was one guideline that I didn't know existed, all others I knew just by looking intuition from looking at other schematics. I'm just a hobbyist
Found a mistake: 0.01 uF is 10 nF, not 100 nF as used in the video at about 45:00. It can also be written 0u01, not 0u1 nor 0n01.
The benefits of being the head cook and bottle washer is you get to use the CAD software schematic to highlight pins and nets on the PCBs layout...I HATE searching for pins to probe. Btw: Good tutorial mate!
Thank you very much for the long Video. I learnd a lot.
Hmm. I use what you'd call "redundant net names" so that the net names during PCB layout aren't just random cryptic auto-generated names. I find this helpful during layout, as I'm not left trying to guess what each resistor is actually doing.
I stared my career as a technician, first in the military (with mil-spec schematics), then in industry while putting myself through university toward my degree in computer engineering (digital half of EE plus all of CS).
Even though I'm primarily a software engineer, I'm screaming death in hardware design review meetings, as I feel I must support the technicians who will eventually have to work on the product and the software folks who'll program it. A good schematic greatly facilitates the work of the entire product team.
Schematics are a representational language, with a syntax and semantics that, when properly used, will support clear communication, not just as static documentation, but also as a functional tool across multiple domains.
I work as a lab mechanic and these days I'd be happy getting any schematic - most equipment manufacturers are not providing them to their customers anymore. But still a great video!
I never tought it is possible to create a schematic like this with Eagle. I would have to scratch my head for a long time if I would like to do it intentionally. Amazing! (especially the rotating labels on the nets)
I'm new to PCB design, but even I find it hard to believe this was drawn by a professional
1:07:13 Maybe it's the practice/rule of thumb of using an electrolytic and ceramic capacitor in parallel for optimum frequency response (they may be different kinds of caps?).
Great video Dave. I think the longer playtime is worth it!
Very impressive. You're definitely good at what you do Dave.
I was so happy to see the improvements, I almost giggled when the second stage of inputs was sorted and placed in a block. I guess that makes me above average nerdy. (At least compared to the general public, not necessarily with the rest of the EEVblog audience)
I can live with that.
Mistakes:
1. USB output on the right!
2. Keep pinout labels at connectors to tell people which pin does what.
3. Keep symbols reusable, so an FPGA or ADC should have logical, not design specific symbols (though the ones here are bad).
Well, it's an USB Power input..?
usb is bidirectional, so thats is why the author put it on the middle its 50% to the left and 50% to the right
Watching stuff like this is the only reason I pass as a "professional design engineer"
thank you for the length! :)
52:36 - On cap CH1 there is a short between it's two pins, like so on CH2.
awwweeee yeeeeaaaaa boiiiii !!
Thanks heaps for doing this video! I can't thank you enough! I really appreciate it
Thank you, very nice tutorial and refresher.
1. Unused net naming required if declaring net classes by harness otherwise unused pins will lack correct electrical constraints
2. Package of the component is essential information of for ex. decoupling cap frequency behavior (10nF 0402 vs 1206) - not clutter! Do not hide it to the bom only or you will end up mistakes not noticed! Same for voltage rating, dielectric, ... build the library so that all operation related essential information of components is visible!
3. Build the library to follow strict graphical guidelinen - no manual adjusting should be needed
4. USE COLORS - red/green for power/ground etc. - much more readable!
5. Generate the components not just yellow boxes - include operational information to clarify what the component is doing. And visualize - green leds are green - not ”B3632f-G”
Ups. In 1 - not harness but blankets.
I disagree about colour coding, i think. I don't want my schematic looking like a christmas present wrapping paper. Also, it makes it impractical when printed in black and white. I think it would be better to solve it logically in a different way.
I think.
I want more of these. Someone should make a channel of just cleaning up open source schematics
12:08 what about putting value of the resistor inside the rectangle? is this also a big no no ?
We put the size in it (0402/0603 etc)
Thank you Dave, to give your valuable experience and put money into my pocket, learned a lesson.
Great video! Thanks! The light red and light blue on a white background is VERY difficult on my eyes though!
At 1:12:20 it looks like four bits got reversed by reordering the labels. I don’t see why it couldn’t be used by the project people. It seems there should be no reason not to send it back.
9:20 No, this is an import issue, look at pdf. Eagle allows you to rotate text 0° or 90° CCW but not 90° CW nor upside down.
I thought I was really bad at reading big schematics, now I now they were crap!
For the 0 v line, the ground symbol is used. I have seen schematics where they used the symbol for the + voltage connector, but downwards. And i have the impression he also used a polarised capacitor symbol on places with a non-polarised capacitor.
Sometimes I do have ground symbols pointing upwards, especially when dealing with negative supply voltages. I like to have the parts arranged vertically like the voltages distribute in the circuit.
I don't like connecting pins with net names. If you make a typo on the names you don't have a connection. I always use either a direct connection using lines or busses, or an off page connector. Then you can add the Intersheet reference on the port and know it's connected.
Excellent, wired of backassward schematics.
7:10 .. one "exception" .. If I have "kind" of an differential pair and want to clearly show that it changes polarity, I draw it like this "=x=" between source and sink. Did that on an ECL circuit one, for example.
up there with the best of your vids old chap
Fantastic! thanks for all the good ideas and information.
I've never had a problem with upside down ground symbols; they're just symbols, not arrows. They look silly if you have to hair-pin bend them or make them cross other nets just to make the symbol point down. And if you have negative voltage rails near the bottom of the page then it makes even less sense to make the ground symbols (higher up the page) point down.
A bit late, but I was just finishing up a schematic of mine and saw this old video in the recommended list.
For the big yellow rectangles framing in the different stages, I would pick a more pale yellow, like Altiums color number 214, so all the yellow parts stand out more. :)
37:15 - i mark wire (power) resistors with zigzaggy thing and film resistors with rectangle.