Si5351 VFO/BFO Software: Part 1 Hardware overview
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- Опубликовано: 1 мар 2018
- Two part video series looking at the software setup used to drive the Si5351.
Part 1 looks at the hardware and what's needed to be worked out prior to writing the software.
Part 2 looks at the software using the knowledge gained in Part 1.
This was the answer to my questions. I saw it earlier and needed to re-see it and keep notes. Thanks again.
Glad it was helpful Dana.
Just bought one of these Si5351 breakout boards. With your video, I'll be able to build a great generator for my direct conversion receiver, thanks!
That's great to hear thanks.
I am enjoying your videos.
Wonderful video as always. Thank you and 73s.
Thanks Ruel. Hopefully, they are of use.
73s
Charlie, ZL2CTM
Good breakdown. I"m trying to learn about all this stuff, very helpful
Another great video Charlie , i will have to get some hardware etc to make up this DDS ,Thanks for sharing . 73's
Go for it. You should be able to make one for well under $20.
Charlie
got your code working on my Pro Mini! I had newer versions of the Si5351 and LiquidCrystal_I2C libraries so had to comb through the code and change a few things. Primarily the initialization of the LCD is different and the set_freq() for the Si5351 has 2 arguments instead of 3.
Excellent. I'm using the Jason Mildrum Si5351 library, which works well for me. I'm glad you have it working.
Charlie ZL2CTM
Awesome 😎 this will help me out heeps iv just started to play around with aduino and would like to build a DDS for experimenting thank you big thumbs up 👍
Excellent. I'm pleased to hear it was useful.
Good work Charlie , the lcd display is better than the oled because the noise ratio is less or none.
PU4ADD BETO BALEIA
Thanks for that. The little OLED screen are great for the portable rigs, but quite noisy. I need to do some more work and see if I can reduce that.
73s
Charlie, ZL2CTM
the besth
Hello Charlie , this new video from you its very informativ for me because your way to explain the steps are simple to understand and its very usefull !!! Have a good time best 73 es 55 de Ralph DB 9 FQ C 31 KM
My pleasure Ralph. I'm really pleased you are finding them useful!
73s also
Charlie.
Hello Charlie,
I just subscribed to your channel. THANK YOU for providing detailed explanations of your schematics and the math involved in determining values of components. Most channels simply give one the schematic with no explanation as to its creation.
From your videos a person can actually learn how to create their own design for a radio. SSDFRA and EMRFD are fantastic resources but being able to see and hear an explanation for the theory is priceless!
Could you please explain how you determined the LO drive current levels for the Level 7 (8 ma.) and Level 3 (2 ma.) mixers? I have a hard time wrapping my head around db and dbm but I believe +7 dbm equates to ~ 5 mw. and +3 dbm to ~ 2 mw. If I assume a 50 ohm input impedance for the LO input of the SBL-1, and use the formula p=I2R I calculate max. current for the Level 7 mixer at 10ma. (very close to your 8ma.) and 6ma. for the Level 3 mixer (not so close to your 2ma.). Am I on the right track?
73,
Terry
Cheers Terry. You might have heard me say that the whole idea of the video series is to encourage others to give it a go, i.e., design their own radio. They are not suppose to be high end radios, which is a reflection of my own limited knowledge and ability. That aside, I personally get so much enjoyment from using a homebrew radio, no matter how good it is. As for the VFO, yes, you are on the right track. I have found that you can just connect up directly the Si5351 (with the software set to 8mA) to a 7dBm mixer (such as the SBL-1) and it works fine. I have not bothered to amplify its output to be exactly on 10mA.
@@CharlieMorrisZL2CTM Charlie-- thanks for the reply. I stumbled across this RF Cafe website that shows the Power/Voltage formulas for deriving these types of answers, and also has a table of conversions already done for those of us who are a little more challenged with the math. This is a pretty good resource.
www.rfcafe.com/references/electrical/pwr2volts.htm
73,
Terry
Thanks Terry.
I use the cursor to indicate the step digit, you can put the cursor on the same line as the frequency number leaving the second line for something else.
I use the pin-change interrupt for the encoder, on the UNO (atmega328 ANY pin can accept pin-change interrupts), both interrupts go to the same routine.
I now would rather use either the AdaFruit Itsy-Bitsy M0 or M4 boards instead of the atmega328 boards. These are 3.3 volt boards.
Yes I have used that approach too and it does work well. It looks tidier too.
Hi charlie, thank you for your detailed hardware review, I am interested in build it as a VFO of an old 80 mts SSB BLU (modified :) ). My question is regarding the output frequency of the Si5351, if am not wrong is and sqare output instead of a sine wave no? So if that happens you simply add a filter to get a clean carrier for example? Thanks in avdance!
You can add a filter. I did that some time ago and it worked well. Otherwise, square waves work well for the simple diode based DBMs.
Great video! What wire are you using to take the signal off of the Si8583?
There are two types there. The black coax is RG174/U and the other has no part number. I got that out of an old FT101. It's great as the center conductor insulation has a high melting point.
Thanks!
Does the Si chip put out square waves? So you just use those for the mixer (instead of a sine)
Yes. The SolderSmoke podcast had an article on this at soldersmoke.blogspot.com/2016/03/great-video-on-mixers.html
Hey Charlie! Just wanted to knew how the rotary encoder works without Vcc. Dies it take power through RotA and RotB or A and B outputs?
Rajaram. The rotary encoders I use only need a ground. No need to Vcc at all.
have you managed to get the Si5351 to output two clocks on the same frequency in quadature (90 degrees apart) for use in an I/Q mixer?
Also ANY Arduino using the ATMega328 chip can accept interrupts on ANY of the pins via the pin change interrupt. (PCINTxx) The INTx pins are more flexible, but I've found the PCINT pins perfect for the encoder use.
On the Arduinos using the atmega32u4, only one of the ports accepts pin change interrupts, and there are a few other pins that can accept interrupts too. (But not ALL of the pins).
Thanks about the pins. As for quadrature clock outputs, yes I did look to use a Si5351 to generate the quadrature VFO frequencies for a SDR radio. Unfortunately, I could not get the phase register to stay below 127, which meant I could only tune as low as 4.7MHz. At that time I wanted to get down to 3.5MHz, so was looking for a way to turn on the R Dividers using the library. Ideally, I was looking to turn on R0 and R1 registers and make them divide by 2. I liaised with the library author and it was not possible. I might try again sometime.
I've read that you can actually set the PLL to about 350mhz, so it might be possible to use quadrature to as low as 3.2mhz, or lower. The thought had also occurred to me that by putting a single external divide by two flip flop in each output which would use as many parts as the divide by 4 usually used to get quadrature output, but the part would no have to operate at only half the frequency. (IE: up to 60mhz instead of 120). Hence a cheaper HC flipflop would work instead of something more exotic.
I guess you're only plugging the perfboard into one side of the Arduino due to that nasty 50 mil pin offset on the bottom row.
BTW do you have a blog / web page somewhere where you've posted software and schematics for your projects? I've started a page myself under blogger.com / wa2mze.
Being able to get 3.5MHz plus quadrature output would be perfect for a simple low parts count SDR radio. That's what I wanted to do with the SDR build last year, but had to resort to the divide 4 flip flop arrangement. I might have a SDR revamp to the projects list!
I do have a blog site that I use to dump schematics and software code. It's at:
www.blogger.com/blogger.g?blogID=7819684856383893520#allposts
73s
Charlie, ZL2CTM
Hey Charlie! De VU2RJV here. Thanks for your awesome videos that has helped me to breadboard this DDS VFO and it works very well.
I am finding it difficult to transfer it into a vero board. Can you help me with the layout details and wiring on this vero board. I am a beginner to home brewing. Even a rough pencil sketch pic would do..73
Any help will be appreciated. 73
Hi Charlie,
I'm going to build my first dds vfo. I have an arduino, I'm buying an si5351 module and would like to use an oled display.
Is there any particular type of display I need (i1c
Your reply would be most welcome, enjoy all your videos!
Good video, don't anything about writing code, but I know how to install it. How about sharing the Code, libraries in a zip file from your google drive. Thanks
My pleasure.
Hi charlie can i use your model like an rf signal generator to adjust sensibility in a hf radio ?????(excuse me i don´t speak english)
I don't see why not William. I use it it in my SSB/CW rigs with no problems.
Charlie
@@CharlieMorrisZL2CTM can you send me the wiring diagram to conect all to the arduino uno board and sketch please???? my mail is yv5jau@msn.com tnx.
@@williamsanchez34 It should be all on the blog William: zl2ctm.blogspot.com/
Charlie
I have a bunch of SBL-1H I think it’s called it’s like a +17dBm drive. How could these ever be usable , never seen anyone build with them. I thought I was getting the +7dBm package when I bought them. Dumb move on my part
Hi Seth. I have not seen any homebrew builds using the SBL-1H. No reason that I can think of why you couldn't use them. You'd need to amplifier the AD9850/Si5351 output to get it up to the 17dBm level needed for the LO drive. Give it a go.
Charlie
Charlie I got problems when I visited your blog. My google account does not allow me to visit it. Could you hel pe, please?