Seems like a good way to learn about a few things like op-amp scaling, DAC control and UI development. I'm designing a fantasy one right now. Then I'll do one I can actually build.
believe me that's nothing. Just read a user guide for any modern micro-controller or FPGA. This user guide for the classic STM32 is over 1000 pages. And it is a low-end chip. The F4, F7, and H7 are gaining popularity in the DIY space now mostly because of more flash space. www.manualslib.com/manual/1276772/St-Stm32f101-Series.html#product-STM32F103%20series
I saw a lot of different videos on RUclips about this topic,but everything seemed to be very complicated Your video was the most simple but yet the best one i come across Keep it going :)
Obviously very late, but the instability and other issues at high frequency are likely due to the construction of the op amp portion of the circuit. Very good decoupling is important, and the output of the op amp should be followed by a resistor so that the transmission line is double terminated (therefore protected from bad loads) and any capacitive loads don't cause phase margin issues.
@@greatscottlab There are libraries for MCP2515 chip for Arduino IDE and there is also a library for using it with CAN Hacker software. Yesterday I tested it out on my STM32 Blue Pill board by using stm32duino and it works great! sun9-69.userapi.com/c857420/v857420683/714f7/aM3nLdigq48.jpg STM32 Blue Pill also has CAN bus support itself so it doesn't even need chips like MCP2515, it only needs CAN tranciever such as TJA 1050.
I think the reason of the malfunctions of these generators are fake IC's, I remember seeing a video of a guy replacing it with a legit one and most problems went away. Of course even original ones have their own limits so there's not that much else it can be done about it
@@TheAzther1 the main reason is shitty op amps with poor slew rate and crappy pcb design. It is not the frequency of the waveform which is the problem. Look at edges of the squarwave. They have to be super fast to reliably generate a square wave. 10MHz squar wave requires edges to rise and fall in like 10ns to keep the signal look like a square wave, not a sine or trapezoid. So to have 10Mhz squarewave you need an op amp with 100MHz bandwith. However, you want to use the op-amp to amplify the waveform, so to have a decent waveform at the output and also a gain of 10 you would need an op-amp with at least 1GHz gain-bandwith product and 100 000 000V/s slew rate to give you 10V p-p voltage. Good luck with that.
One of the problems with those is the crappy Switch mode power supplies that have been fitted inside them, which is not what you need with a sig gen, people have modded them very easily with linear power supplies though so not all bad. Few good channels on YT cover this.
@@Adrian_Finn The noise from the switch mode power supply is though far from bad on the units. Since it gets drowned by the harmonics from the signal generator itself. Also, a linear power supply will generally couple through all the noise from one's mains wiring, so have a computer or other switch mode powered device connected nearby and you will have just as much noise from the linear supply. In any case, the issue can easily be rectified by adding a bit of extra output filtering from the supply, not that this matters much due to the signal generator already having enough harmonics and other crap that it literally drowns the noise from the power supply. (In the end, I wouldn't recommend practically any DDS for RF use, obviously.)
The real issue with these devices is the floating AC on the earth side of the BNC connectors (measured with reference to a true earth.) Not enough current behind it to harm you but more than enough there to fry the delicate inputs to a microcontroller.
@@SpeccyMan This is indeed a problem. I solved it by adding a wire going over to mains earth. Seemed trivial enough. Though, to an exceptionally small degree, one could regard the non-earthness of it as a "feature", if it weren't for the huge amounts of common mode noise...
Hi Scott. I think a great video would be basically a video focused on the parts you usually skip on the videos. So for example let's say you choose something simple like a power supply diy build. Go through step by step buying and ordering the parts. And the soldering as well. Maybe 3d design if it applies for the project
This is really a nice project. I bought a used Philips/Fluke PM 5191 Programmable Synthesizer/Function Generator for $85. It's 0.1 to 2 MHz. Interesting device.
I really like your content, and I appreciate how clear you are with your whole process, especially the analysis of data sheets and circuit diagramming. Thank you!
FYI: AD9834 is a faster DDS. Also a ground plane may help w/noise and stability. Nice video, I appreciated the information. Thinking about DIY to upgrade from my 40 year old Circuitmate.
Nice one! I bought a $50 Chinese DDS function gen a few years ago and found navigating its menu frustratingly cumbersome and its outputs distorted, full of hash and ringing badly. You get what you pay for, I kept telling myself. I then replaced its two output op amps with ones having a better slew rat, per some online videos I found, and got better looking waveforms with less ringing, though they're still not lab instrument quality. In the end I probably spent too much for a cheapie DDS function gen but the experience taught me a few things about how these things operate.
Great work. You should have designed a PCB with good RF characteristics in order to achieve much better High frequency performance. Additional Filter circuits on the in- and output also would have made a significant difference. Also choosing a low noise op amp on the last stage is mandatory. Anyway great project!
I bought the UDB1008s 8Mhz function gen from aliexpress for 20 bucks. It does very clean 7Mhz sine, and okay 700kHz square and triangle, with sawtooh and pwm support. Perfect for DIY.
I love this channel. It inspires me to persue the hobby. Unfortunately, or perhaps fortunately, I understand I will never take my skill to his level. I just want to build a custom keyboard and a programmable universal remote.
TL071 is not suitable for 10MHz signals,and that's why your freq. gen. deos not work properly at high frequencys. Also, I don't see any decoupling capactors (approx. 0.1uF) near IC power pins. Using high frequency opamp and adding decoupling caps should fix high frequency issues
@@ObligedTester I know this comment is from a while ago but as I just looked at this based on other comments in this thread this might be helpful for others. Find something low noise and high speed (select this based on your desired max frequency). You may want to consider slew rate as well @w2aew has a great video that explains slew rate and gain bandwidth product for opamps on his youtube channel that will help.
@@yagneshpatel1183 friends I bought this operation amplifier!!!!Still I have not received any of my items about this project!!!I wanna make this project in 5volts!!!I have dc-dc converter from 5volts to 12volts (the MT3608) and I have the converter from 12volts to -12volts...At first I worry about the output signal voltages because I made my own serial oscilloscope with arduino and the max input is in 5volts and I want to control the output voltage
I love your build vs buy series. Couldn´t you expand this to give you an arbitrary function generator if you added a keypad to the Arduino to punch in voltages?
This will be useful - I need several inexpensive function generators for our electrochemistry lab. I hadn't seen anything over 100 kHz. (I confess I hadn't searched in the last five years.) Thank you.
To have better performance at high frequencies, you should used opamps with higher gain bandwidth products (GBP). Because the DDS would not give wrong signal it is only the mistake of signal processing. It seems that you are using TL071 opamp which has GBP of 5.25Mhz and you are using it to amplify by a factor of 22, so the bandwidth of this configuration of opamp will give you a reliable signal bandwidth of around 23 khz
Just finished build and testing one (still prototype) and I have to say I don't see this signal instability at about 5MHz using my old analog scope connected at the 9833 output pin. Even being this the top frequency for my instrument. You probably was experiencing some other problem, not 9833's fault. I plan to build a second signal stage, so I can use it to extend sweep range frequency on my scopt, and (hopefully) observe its wave forms at higher frequencies. Anyway, thanks for sharing. Your videos are awesome!
Hey, do you mind sharing your build or some tips/tricks? I'm having issues getting the entire thing to work. Nothing seems to happen when you turn the rotary encoder. Any ideas? The AD9833 does output a 1.04 kHz sine wave of
Love the project, just a reminder that 123D is discontinued and basically superceded by Fusion 360 (which is also free for hobbyists, students, and small startups).
Excellent work since 3 days I made this FUNCTION GENERATOR... I used the MT3608 DC TO DC CONVERTER to convert from 5v to 12v then I used the DDO315NA to convert from +12v to - 12v for the TL071CP.... I made the project with Arduino uno r3 atmega 328p!!!!FINE PROJECT!!! 😎😎😎😎😎😎
Hi. Did you test function generator output signal with oscop? I made this circuit and connected to oscop as following resultes: - Frequency set to 2000Hz, sin and triangle wave frequency showing 2000Hz but on square wave showing 1000Hz. - Frequency set to 3000Hz, sin and triangle wave frequency showing 3000Hz but on square wave showing 1500Hz. square wave frequency always showing 1/2 of the set frequency.
@@majidarabi3694 In theory a square wave has an instantaneous rise and fall. But it has a dwell time based on the frequency. Lets take a 1 hz square wave. The signal goes from zero to 100% in an instant. Then will remain at 1 for 1/2 of the wave length or 500ms.
Thanks for your advise. I tried another function generator circuit diagram and code " www.instructables.com/Portable-Function-Generator-on-Arduino/" Sin,triangle and squre wave frequency are correct with that but with your circuit sin and triangle are corect and squre wave is 1/2. Fault finding is in progress.
@@majidarabi3694 I made this function generator with Arduino Uno R3 atmega 328p ruclips.net/video/r0zzqB-oUF4/видео.html but if you watch my channel I made and ANALOG FUNCTION GENERATOR KITS BY E-BAY!!! I watched that and in Analog Function Generator kits by the Ebay the square wave has half past frequency than Sine and Triangle waves
Personally i prefer second hand electronics from ebay over some DIY project: if you have the time to search for bargains, you can score some amazing deals. And if you know how to repair electronics, you can get a pretty nice setup for cents on the dollar: Just browse for broken equipment, google the schematics and if you find them, buy it. I have gotten two Oltronix B703 (basically three really nice separate power supplies in one small box) for 35 bucks among other stuff. Yes, it can be frustrating and time consuming to repair it, but it is totally worth it.
Actually You almost fit my current project :) I am building DIY Function generator based on AD9834 (35MHz), but most of Your written problems are the same. About Amplitude and Offset - Need to use it with meaning, that its not going out of OpAmp power range. I am planning to use STM32F072 wich have 12bit DACs integrated to control offset and amplitude of AD9834. Amplifiers will be LM7171. I'll add also one PWM output from STM as second channel. As display its planned to OLED 2.4" with SSD1309 controller. About power supply I am still thinking - I think I should use some linear stabilisers for better power quality. Possibly Transformer is very good choise for analog part. For digital part can be used also SMPS. Allready bought some old function generator case with buttons on eBay and AD9834 board from AliExpress - so now is only breadboarding and testing and coding. Thanks for Your review about this topic man!!!
I've been trying out an AVR microcontroller with an R2R DAC and well, it kinda worked. Needs some polishing though, as adjustable offset and amplitude can be useful. It seems like a must have for a guitar pedal enthusiast, at least for me.
Having worked with audio at uni, I can say that 10-bit DACs will easily handle most music without any noticible noise. The thing you want is sampling frequency
@@telefon72 True. But good luck telling that to an Audiofool who believes there equipment sounds better by using cryogenically frozen unobtainium power cable.
Awesome video AS ALWAYS! I think it would be awesome if you could do a DIY-OR-BUY on TL-smoothers used to remove the salmon-skin effect on 3d printed parts. Seems like a quick project that would be really interesting! Thanks for all of the great content!
Mate, I gotta say, I frikkin love you for these instructable videos. I've already built an audio amp that works real good thanks to that vid and project page. You ever consider compiling a library that can be put on an internet in a box?
I am using function generator, but the problem is that the output is very low power. I have been looking for amplifier that could work witch signals up to 1MHz, but I cannot find anything that can produce reliable signal, with current up to 5 A. I am an electronics hobbyist and I have problems with coming up with my own designs, but i want to learn by testing different circuit properties with my function generator. I found commercial amplifiers but these are still too expensive for me. Do you have any inputs on that topic?
Great video as usual :) I have a XR2206, the same one in the video(very common I know) and it work fine for now but if I ever need an upgrade I'm doing this. Thank you sir!
you already have an awesome function gen, no need to make a new function gen to solve this problem, just buffer and amplify the signals produced by your existing one
@@JensRoland plenty of them, google the high frequency LNA I love scott videos, but I'd like to see his projects successful. Even though these mistakes might be done to let audience think what has gone wrong, I personally would like to see a project done working properly.
@@cantekdemir1972 now that would be amazing if that would work lol but I can see someone connecting 2 phases together and seeing the sparks fly as you short 2 120v lines (I used 120 in the example because I'm canadian)
A general purpose waveform generator is a rarely used lab instrument. If your circuit requires waveforms, it's best to design it with self-test in mind.
GreatScott! Could you please make a video comparing spectral performance of DDS, XR-2206 and AE20125? I'm curious about their SFDR (first harmonic amplitude) and spectrum in general for 50 Ohm and 600 Ohm load.
So I found an old digital TV converter PSU that supplies +12, -12v and 5v (among others) as screen printed on the PCB BUT on measurement the 12v lines only measure + and - 11v. I assume this will still work for the rest of the design but limit the signal Gen to + and - 11v rather than the 12v you wanted.
great project i was waiting for it until I found another DIY function generator on google which contains more functions than your version like saw tooth or ECG or noise with R2R DAC but it's maximum frequency is 0.65 MHz so i think both are good
I bought on ebay an old function generator for 30€. It has nearly the same functions as the diy one and is at some points better. I think this is the best and easiest way.
An old PC power supply can be an excellent way of getting +12v, -12v and +5v. You also get +3.3v thrown in as an extra. They are easier to work with than a transformer for the less profficient tinkerer, especially if you use one of the cheap boards available from China that breaks out the voltages from the motherboard connector to the individual voltages and includes fuses.
Depends what you are doing with it. Someone who does vintage restoration, for example, will want the high-voltage, low-current signals used in valve equipment.
Hi Scott, could you add a comparison of AD9833,XR2066, Siglent SDG 2082X and AE20125? with THD Values for example to see how far you´re away from "High Tech". And a Question concerning the unstable signal from AD9833 at a few MHz..do you think it´s just how this DDS works or could it be the Bandwith of your TL071 Opamp? And thanks for this great video, im trying to bild my own AD9833 and this helps a lot! ;)
I was looking at the same expensive one you have the Siglent or whatever.. That with the Oscilloscope from the same company comes to about $800usd give or take. I love electronics and want to be like you when working with them so it would probably be best for me to buy the good one and learn everything it does, right? I still might build this anyway. Because the 4 channel Oscilloscope is more important to me for now.
This is a nice project. Thanks for the video! I'm going to build it! One question: The parts list in your Inventables article specifies a 24V center-tapped transformer. I thought the LM7812 and 7912 had a dropout voltage of around 2.5 volts, so to get +/- 12 volts you'd need to feed them at least +/- 14.5. Or basically a 30V center-tapped transformer rather than a 24V one. Those seem a lot harder to find, though Digikey has a few. What am I missing?
A friend answered this question for me.... The 24V transformer outputs +/- 12V RMS so the peak voltage will be the 12 * √2, or around +/- 16V. More than enough. (If you couldn't tell, I'm a total beginner. I just started trying to learn electronics recently after retiring from a software engineering career.)
The non required responce for the DIY function generator at 5 MHz , is may be due to the OpAmp used -TL071- which it's datasheet state that its BandWidth is just 5MHz. while the AD9833 capable of output up to 12.5MHz, which is also great for your project. its recommended to se LM118 Or LM218 ,,, etc which have a bigger Bandwidth ( about 15MHz). Thanks for your videos, and stay creative .
One wouldn't test the bandwidth of an opamp circuit that way, to begin with because opamps don't work well as high frequency, low gain amplifiers (look up Miller capacitance to understand why). Look at the data sheets for suggestions on how to measure the gain-bandwidth product in a high gain configuration. If you need a 10MHz bandwidth buffer, look at JFET buffer circuits. For properly terminated signals (50-200Ohm), transimpedance amplifiers are a good choice.
Nice project. I am wanting an Oscilloscope. Could have bought one a few years back at a Hamfest (Amateur Radio swap meet) for around $45 but passed on it and now I'm kicking myself for not getting it.
nice thanks for all helping video and content your so amazing, but I have a question? what is the output current of the transformer because you put a 2 amp fuse and then with an 8 amp full bridge diode you get 0.8 amp current at the output,Im a bit confused,can you help me?
-"it did't result in an explosion, perfect"
Electroboom disaproves
Nice to see someone out in there thinking like me.
ElectroBOOM's soul cries in pain until he can murder some capacitors.
Every time happy while first turning on without BOOM.
-(Audience)- "Awww...."
ye lmfao
I've been wanting to build my own function generator for a while now. Thanks for posting this.
You're welcome ;-)
@@greatscottlab ; - )
Seems like a good way to learn about a few things like op-amp scaling, DAC control and UI development. I'm designing a fantasy one right now. Then I'll do one I can actually build.
@@meepk633 Post up both pls
Likewise, maybe this is the one to build.
"This picture may seem complicated.... but if you study this 21 PAGE DOCUMENT it becomes pretty simple." heh
That's a pretty small price to pay for knowledge.
The Mad Philosopher do you just wander around deflating other people’s humor with trite remarks?
believe me that's nothing. Just read a user guide for any modern micro-controller or FPGA. This user guide for the classic STM32 is over 1000 pages. And it is a low-end chip. The F4, F7, and H7 are gaining popularity in the DIY space now mostly because of more flash space.
www.manualslib.com/manual/1276772/St-Stm32f101-Series.html#product-STM32F103%20series
i hope you never study anything then, because each script you get there is houndreds of pages, 21 pages is a joke.
Your DIY or Buy is my favorite RUclips segment. I always look forward to these. Great job!
Awesome! This goes on my (already long) project list.
And the list is long, and the know-how lags the list! 😆
I saw a lot of different videos on RUclips about this topic,but everything seemed to be very complicated
Your video was the most simple but yet the best one i come across
Keep it going :)
Thank you very much :-)
Obviously very late, but the instability and other issues at high frequency are likely due to the construction of the op amp portion of the circuit. Very good decoupling is important, and the output of the op amp should be followed by a resistor so that the transmission line is double terminated (therefore protected from bad loads) and any capacitive loads don't cause phase margin issues.
You are great teacher.
I always wait for your video.
Keep up man....
Thanks :-)
I would like to see a video about CAN Bus Systems. Thumbs up for the video man
I can put it on my to do list
@@greatscottlab There are libraries for MCP2515 chip for Arduino IDE and there is also a library for using it with CAN Hacker software.
Yesterday I tested it out on my STM32 Blue Pill board by using stm32duino and it works great!
sun9-69.userapi.com/c857420/v857420683/714f7/aM3nLdigq48.jpg
STM32 Blue Pill also has CAN bus support itself so it doesn't even need chips like MCP2515, it only needs CAN tranciever such as TJA 1050.
素晴らしい語り口。引き込まれてしまう。wonderful narrative. I am drawn to the charm.
The squarewave output of those cheap nasty red functiongens alsow works as a sine wave above 100khz
Just reduce the amplitude of the wave and it should look more like a square wave because of reduced time for charging external capacitors
Lol, that's an additional feature .
I think the reason of the malfunctions of these generators are fake IC's, I remember seeing a video of a guy replacing it with a legit one and most problems went away. Of course even original ones have their own limits so there's not that much else it can be done about it
@@TheAzther1 the main reason is shitty op amps with poor slew rate and crappy pcb design. It is not the frequency of the waveform which is the problem. Look at edges of the squarwave. They have to be super fast to reliably generate a square wave. 10MHz squar wave requires edges to rise and fall in like 10ns to keep the signal look like a square wave, not a sine or trapezoid. So to have 10Mhz squarewave you need an op amp with 100MHz bandwith. However, you want to use the op-amp to amplify the waveform, so to have a decent waveform at the output and also a gain of 10 you would need an op-amp with at least 1GHz gain-bandwith product and 100 000 000V/s slew rate to give you 10V p-p voltage. Good luck with that.
FY6800 DDS Signal Generator/Counter is amazing value for money - worth a look for anyone considering a budget unit.
One of the problems with those is the crappy Switch mode power supplies that have been fitted inside them, which is not what you need with a sig gen, people have modded them very easily with linear power supplies though so not all bad. Few good channels on YT cover this.
@@Adrian_Finn The noise from the switch mode power supply is though far from bad on the units.
Since it gets drowned by the harmonics from the signal generator itself.
Also, a linear power supply will generally couple through all the noise from one's mains wiring, so have a computer or other switch mode powered device connected nearby and you will have just as much noise from the linear supply.
In any case, the issue can easily be rectified by adding a bit of extra output filtering from the supply, not that this matters much due to the signal generator already having enough harmonics and other crap that it literally drowns the noise from the power supply. (In the end, I wouldn't recommend practically any DDS for RF use, obviously.)
The real issue with these devices is the floating AC on the earth side of the BNC connectors (measured with reference to a true earth.) Not enough current behind it to harm you but more than enough there to fry the delicate inputs to a microcontroller.
@@SpeccyMan You seem to be referring to the FY6600, not the FY6800.
@@SpeccyMan This is indeed a problem.
I solved it by adding a wire going over to mains earth. Seemed trivial enough.
Though, to an exceptionally small degree, one could regard the non-earthness of it as a "feature", if it weren't for the huge amounts of common mode noise...
nice project ,you could use AD9851 or AD9850 for higher frequency ,btw it should be possible to modulate signal eg. AM or FM ,it may be useful
Hi Scott. I think a great video would be basically a video focused on the parts you usually skip on the videos. So for example let's say you choose something simple like a power supply diy build. Go through step by step buying and ordering the parts. And the soldering as well. Maybe 3d design if it applies for the project
This is really a nice project. I bought a used Philips/Fluke PM 5191 Programmable Synthesizer/Function Generator for $85. It's 0.1 to 2 MHz. Interesting device.
A waveform generator has been on my want list for a very long time!
One of the first comments!!!
“One point five years ago” that had me laugh some
Nobody talks like that :-)
I really like your content, and I appreciate how clear you are with your whole process, especially the analysis of data sheets and circuit diagramming. Thank you!
FYI: AD9834 is a faster DDS. Also a ground plane may help w/noise and stability. Nice video, I appreciated the information. Thinking about DIY to upgrade from my 40 year old Circuitmate.
Nice one! I bought a $50 Chinese DDS function gen a few years ago and found navigating its menu frustratingly cumbersome and its outputs distorted, full of hash and ringing badly. You get what you pay for, I kept telling myself. I then replaced its two output op amps with ones having a better slew rat, per some online videos I found, and got better looking waveforms with less ringing, though they're still not lab instrument quality. In the end I probably spent too much for a cheapie DDS function gen but the experience taught me a few things about how these things operate.
I simply enjoy your videos even if I have no plans to build this circuit.
Great work. You should have designed a PCB with good RF characteristics in order to achieve much better High frequency performance. Additional Filter circuits on the in- and output also would have made a significant difference. Also choosing a low noise op amp on the last stage is mandatory. Anyway great project!
DIY will always be the ☆Winner☆ - for when it comes to test gear.
I bought the UDB1008s 8Mhz function gen from aliexpress for 20 bucks. It does very clean 7Mhz sine, and okay 700kHz square and triangle, with sawtooh and pwm support. Perfect for DIY.
Nice video! I'd like to see in a future DIY or buy episode an RLC meter.
I really like the way that you said when you "stole" his code to "save time and effort"
I love this channel. It inspires me to persue the hobby. Unfortunately, or perhaps fortunately, I understand I will never take my skill to his level.
I just want to build a custom keyboard and a programmable universal remote.
TL071 is not suitable for 10MHz signals,and that's why your freq. gen. deos not work properly at high frequencys. Also, I don't see any decoupling capactors (approx. 0.1uF) near IC power pins. Using high frequency opamp and adding decoupling caps should fix high frequency issues
Great info, thanks! Any recommendations for OP-amp?
@@ObligedTester I know this comment is from a while ago but as I just looked at this based on other comments in this thread this might be helpful for others. Find something low noise and high speed (select this based on your desired max frequency). You may want to consider slew rate as well @w2aew has a great video that explains slew rate and gain bandwidth product for opamps on his youtube channel that will help.
TL071 IS AUDIO IC NOT FOR INDUSTRIAL GRADE . BETTER SWITCH TO MCP SERIES IS BETTER
@@yagneshpatel1183 friends I bought this operation amplifier!!!!Still I have not received any of my items about this project!!!I wanna make this project in 5volts!!!I have dc-dc converter from 5volts to 12volts (the MT3608) and I have the converter from 12volts to -12volts...At first I worry about the output signal voltages because I made my own serial oscilloscope with arduino and the max input is in 5volts and I want to control the output voltage
lm6171 it's a good option
I really like this series as I really like to do diy over buying things. I think a diy or buy on a UPS for a future video idea!
I love your build vs buy series. Couldn´t you expand this to give you an arbitrary function generator if you added a keypad to the Arduino to punch in voltages?
diy is always the winner as knowledge is priceless and indefinitely replicable
This will be useful - I need several inexpensive function generators for our electrochemistry lab. I hadn't seen anything over 100 kHz. (I confess I hadn't searched in the last five years.) Thank you.
Finally, a project and a good lab instrument for Electronics Hobiests....
To have better performance at high frequencies, you should used opamps with higher gain bandwidth products (GBP). Because the DDS would not give wrong signal it is only the mistake of signal processing. It seems that you are using TL071 opamp which has GBP of 5.25Mhz and you are using it to amplify by a factor of 22, so the bandwidth of this configuration of opamp will give you a reliable signal bandwidth of around 23 khz
Always enjoy your videos!
Saying hello from Santiago de Chile
Just finished build and testing one (still prototype) and I have to say I don't see this signal instability at about 5MHz using my old analog scope connected at the 9833 output pin. Even being this the top frequency for my instrument. You probably was experiencing some other problem, not 9833's fault. I plan to build a second signal stage, so I can use it to extend sweep range frequency on my scopt, and (hopefully) observe its wave forms at higher frequencies. Anyway, thanks for sharing. Your videos are awesome!
Hey, do you mind sharing your build or some tips/tricks? I'm having issues getting the entire thing to work. Nothing seems to happen when you turn the rotary encoder. Any ideas? The AD9833 does output a 1.04 kHz sine wave of
Love the project, just a reminder that 123D is discontinued and basically superceded by Fusion 360 (which is also free for hobbyists, students, and small startups).
Excellent work since 3 days I made this FUNCTION GENERATOR... I used the MT3608 DC TO DC CONVERTER to convert from 5v to 12v then I used the DDO315NA to convert from +12v to - 12v for the TL071CP.... I made the project with Arduino uno r3 atmega 328p!!!!FINE PROJECT!!! 😎😎😎😎😎😎
Hi.
Did you test function generator output signal with oscop?
I made this circuit and connected to oscop as following resultes:
- Frequency set to 2000Hz, sin and triangle wave frequency showing 2000Hz but on square wave showing 1000Hz.
- Frequency set to 3000Hz, sin and triangle wave frequency showing 3000Hz but on square wave showing 1500Hz.
square wave frequency always showing 1/2 of the set frequency.
@@majidarabi3694Yes I watched it!!!!
@@majidarabi3694 In theory a square wave has an instantaneous rise and fall. But it has a dwell time based on the frequency. Lets take a 1 hz square wave. The signal goes from zero to 100% in an instant. Then will remain at 1 for 1/2 of the wave length or 500ms.
Thanks for your advise.
I tried another function generator circuit diagram and code " www.instructables.com/Portable-Function-Generator-on-Arduino/"
Sin,triangle and squre wave frequency are correct with that but with your circuit sin and triangle are corect and squre wave is 1/2.
Fault finding is in progress.
@@majidarabi3694 I made this function generator with Arduino Uno R3 atmega 328p ruclips.net/video/r0zzqB-oUF4/видео.html but if you watch my channel I made and ANALOG FUNCTION GENERATOR KITS BY E-BAY!!!
I watched that and in Analog Function Generator kits by the Ebay the square wave has half past frequency than Sine and Triangle waves
Simple and superb function genatator at cheapest prices..👌👌👌
Personally i prefer second hand electronics from ebay over some DIY project: if you have the time to search for bargains, you can score some amazing deals. And if you know how to repair electronics, you can get a pretty nice setup for cents on the dollar: Just browse for broken equipment, google the schematics and if you find them, buy it. I have gotten two Oltronix B703 (basically three really nice separate power supplies in one small box) for 35 bucks among other stuff. Yes, it can be frustrating and time consuming to repair it, but it is totally worth it.
Actually You almost fit my current project :) I am building DIY Function generator based on AD9834 (35MHz), but most of Your written problems are the same.
About Amplitude and Offset - Need to use it with meaning, that its not going out of OpAmp power range. I am planning to use STM32F072 wich have 12bit DACs integrated to control offset and amplitude of AD9834. Amplifiers will be LM7171. I'll add also one PWM output from STM as second channel. As display its planned to OLED 2.4" with SSD1309 controller. About power supply I am still thinking - I think I should use some linear stabilisers for better power quality. Possibly Transformer is very good choise for analog part. For digital part can be used also SMPS. Allready bought some old function generator case with buttons on eBay and AD9834 board from AliExpress - so now is only breadboarding and testing and coding. Thanks for Your review about this topic man!!!
Really like the DIY or Buy episodes
I've been trying out an AVR microcontroller with an R2R DAC and well, it kinda worked. Needs some polishing though, as adjustable offset and amplitude can be useful.
It seems like a must have for a guitar pedal enthusiast, at least for me.
You could easily have built the op amp offset for the 70 Euro commercial unit and saved so much work!
FY6800 from Banggood and others is about $90 US. 60MHz 20Vp-p output with a decent display and a normal case.
Even though that it's difficult to understand but I like to watch your videos
5:43 only 10 bit DAC? Audiophiles are coming to get ya.
Not only audiophiles but just people who need accurate voltages for anything
Thats what happens when you use an all-but obsolete microcontroller...
@@power-max Spoken like a true ignoramus.
Having worked with audio at uni, I can say that 10-bit DACs will easily handle most music without any noticible noise. The thing you want is sampling frequency
@@telefon72 True. But good luck telling that to an Audiofool who believes there equipment sounds better by using cryogenically frozen unobtainium power cable.
Awesome video AS ALWAYS! I think it would be awesome if you could do a DIY-OR-BUY on TL-smoothers used to remove the salmon-skin effect on 3d printed parts. Seems like a quick project that would be really interesting! Thanks for all of the great content!
Please do a video about whether should one build a diy 200MHz oscilloscope or just buy one.
What kind of filament did you use for the box of your Function Generator? I really like how it looks
Mate, I gotta say, I frikkin love you for these instructable videos. I've already built an audio amp that works real good thanks to that vid and project page. You ever consider compiling a library that can be put on an internet in a box?
Ever time I see ur videos notification I hope for the drone video
hoping the day comes soon
Not soon.
It would be great to create a function generator with also sine sweep and random noise signals.
I am using function generator, but the problem is that the output is very low power. I have been looking for amplifier that could work witch signals up to 1MHz, but I cannot find anything that can produce reliable signal, with current up to 5 A. I am an electronics hobbyist and I have problems with coming up with my own designs, but i want to learn by testing different circuit properties with my function generator. I found commercial amplifiers but these are still too expensive for me. Do you have any inputs on that topic?
Hello Great Scott can you tell me please the type of filament used for the 3d printed case?
I used galaxy black Prusament
GreatScott! Thanks - great looking finish on that enclosure!
Great video as usual :) I have a XR2206, the same one in the video(very common I know) and it work fine for now but if I ever need an upgrade I'm doing this. Thank you sir!
heeey ! the ad9833 part you ued in easy eda , was made by me ! xaxax im proud tho see it fetured in your video !
Haha thanks for your good work :-)
im in the prosses to create my own fully digital controlable dds fg
you already have an awesome function gen, no need to make a new function gen to solve this problem, just buffer and amplify the signals produced by your existing one
Could the distortion at the top end be solved with a better op-amp?
I was thinking the same, tl071 is like a 40yr old opamp by now. Probably better isolation and shielding of the signals would help toi
Holy crap. This video is perfect. I was just researching the xr2206
Thank you. Glad you like it :-)
have a look to the JDS6600 function gen, it Outputs up to 20V+/- and easy up to 16MHz and it can do programmed waveforms… cost appx 60$
Danke für das Design, ich werde es wohl mit 2x 9V Batterien nachbauen.
Sweet! Thanks for making this. I think I can use something similar to this for my research doing phase shift keying.
Fantastic work, dude! 😃
I may make one some day! 😃
Thank you for this project. I am looking for this for along time.
TL071 is limited to 4Mhz, such a simple mistake...
maciolos9 well spotted - any good alternatives he could use instead?
@@JensRoland plenty of them, google the high frequency LNA
I love scott videos, but I'd like to see his projects successful. Even though these mistakes might be done to let audience think what has gone wrong, I personally would like to see a project done working properly.
maciolos9 so maybe something like the NE5532?
@@JensRoland Taking a quick glance - yes.
Even fits for the non-differential input voltage purposes
2.5MHz in worst case
Very good video
You are great elektronik teacher
I don't know why somebody need that, just connect anything to 50Hz 230v sine wave generator, which is all around us.
Lol
But what if you want 51Hz?
@@UberAlphaSirus connect another plug in parallele lol
@@cantekdemir1972 now that would be amazing if that would work lol but I can see someone connecting 2 phases together and seeing the sparks fly as you short 2 120v lines (I used 120 in the example because I'm canadian)
A general purpose waveform generator is a rarely used lab instrument. If your circuit requires waveforms, it's best to design it with self-test in mind.
Oooh! New colours of the markers!
GreatScott! Could you please make a video comparing spectral performance of DDS, XR-2206 and AE20125?
I'm curious about their SFDR (first harmonic amplitude) and spectrum in general for 50 Ohm and 600 Ohm load.
Excellent video. Very helpful
Don't copy
Do something different own
New ideas
Best explaination
This is the reason, i wait for great Scott's videos 🥰🥰
So I found an old digital TV converter PSU that supplies +12, -12v and 5v (among others) as screen printed on the PCB BUT on measurement the 12v lines only measure + and - 11v. I assume this will still work for the rest of the design but limit the signal Gen to + and - 11v rather than the 12v you wanted.
Cezar Chirila, bravo si salutari!
What filament you used to print the housing?
Galaxy Black Prusament
@@greatscottlab Thanks!
great project i was waiting for it until I found another DIY function generator on google which contains more functions than your version like saw tooth or ECG or noise with R2R DAC but it's maximum frequency is 0.65 MHz so i think both are good
I think buy is the winner here if you want more functionality which you will want eventually if you’re interested in electronics.
I bought on ebay an old function generator for 30€. It has nearly the same functions as the diy one and is at some points better.
I think this is the best and easiest way.
An old PC power supply can be an excellent way of getting +12v, -12v and +5v. You also get +3.3v thrown in as an extra. They are easier to work with than a transformer for the less profficient tinkerer, especially if you use one of the cheap boards available from China that breaks out the voltages from the motherboard connector to the individual voltages and includes fuses.
What do you need amplitudes >5V for on a frequency generator? I think for a beginner on low budget the XR-2206 is THE way to go!
Also, after the beginner gets fed up with the 5 Vpp he could just build an amplifying stage to get more Vpp and a bigger range for the dc offset.
Depends what you are doing with it. Someone who does vintage restoration, for example, will want the high-voltage, low-current signals used in valve equipment.
Next video: Space shuttle; DIY or buy😂😂
We all know which option elon musk opted for ;)
i have build it & it worked fine , thanks.. however how much max amps it can give output ?
Oh my, the DDS is very clever. I like it.
Nice project after a "while"
09:09 and 09:11
And that's where ElectroBoom[friend of GreatSott] comes into play. LMFAO!
Hi Scott, could you add a comparison of AD9833,XR2066, Siglent SDG 2082X and AE20125? with THD Values for example to see how far you´re away from "High Tech". And a Question concerning the unstable signal from AD9833 at a few MHz..do you think it´s just how this DDS works or could it be the Bandwith of your TL071 Opamp? And thanks for this great video, im trying to bild my own AD9833 and this helps a lot! ;)
Tl071 has a gain bandwidht product of 3MHZ so i was going to say the same thing, luckily i found your comment after a little while.
I was looking at the same expensive one you have the Siglent or whatever.. That with the Oscilloscope from the same company comes to about $800usd give or take. I love electronics and want to be like you when working with them so it would probably be best for me to buy the good one and learn everything it does, right? I still might build this anyway. Because the 4 channel Oscilloscope is more important to me for now.
This is a nice project. Thanks for the video! I'm going to build it!
One question: The parts list in your Inventables article specifies a 24V center-tapped transformer. I thought the LM7812 and 7912 had a dropout voltage of around 2.5 volts, so to get +/- 12 volts you'd need to feed them at least +/- 14.5. Or basically a 30V center-tapped transformer rather than a 24V one. Those seem a lot harder to find, though Digikey has a few. What am I missing?
A friend answered this question for me.... The 24V transformer outputs +/- 12V RMS so the peak voltage will be the 12 * √2, or around +/- 16V. More than enough.
(If you couldn't tell, I'm a total beginner. I just started trying to learn electronics recently after retiring from a software engineering career.)
The non required responce for the DIY function generator at 5 MHz , is may be due to the OpAmp used -TL071- which it's datasheet state that its BandWidth is just 5MHz.
while the AD9833 capable of output up to 12.5MHz, which is also great for your project.
its recommended to se LM118 Or LM218 ,,, etc which have a bigger Bandwidth ( about 15MHz).
Thanks for your videos, and stay creative .
One wouldn't test the bandwidth of an opamp circuit that way, to begin with because opamps don't work well as high frequency, low gain amplifiers (look up Miller capacitance to understand why). Look at the data sheets for suggestions on how to measure the gain-bandwidth product in a high gain configuration. If you need a 10MHz bandwidth buffer, look at JFET buffer circuits. For properly terminated signals (50-200Ohm), transimpedance amplifiers are a good choice.
Can you pls test cheap (50-400) beiginner osciloscopes
I've got about 400 quid to spend, and I kinda no what functions i need but would also like Mr G's opinion too
i love the siglent 1104 x-e
Try siglent sds1052dl is a 260$ osciloscope(the ceapest) but it would be nice to have a proper reivew
amazing project, which filament did you used?
You are clever. You can all of electronic. Good luck.
Hi I'm your biggest fan.
I always wait for your videos💜💜
Thanks :-)
Nice project. I am wanting an Oscilloscope. Could have bought one a few years back at a Hamfest (Amateur Radio swap meet) for around $45 but passed on it and now I'm kicking myself for not getting it.
This was epic. Thank you for sharing it.
nice thanks for all helping video and content your so amazing, but I have a question? what is the output current of the transformer because you put a 2 amp fuse and then with an 8 amp full bridge diode you get 0.8 amp current at the output,Im a bit confused,can you help me?
I am very big fan of you. Please make a video on your Electronics lab.
I guess DIY will win! 🙂
before Watching the video
What can we do for output the frequency greater than the 5Mhz