Oh the humanity! Pete Juliano has turned his digital attention to previously completed projects. Perfectly fine rigs -- whose only crime was that they used LC or crystal (VXO) oscillators -- are now being ARDUINOED by the maniacal Dr. Juliano. Not even Huff and Puffs will be spared. This is like the French Revolution! We hear that Pete has even mastered the art of cutting the square holes that are needed for his "displays," so there is no stopping him now.
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I put this in a box this morning. Arduino + AD9850 shield by Paul M0XPD and Kanga UK. Code by AD7C. One stage amplifier by Pete Juliano N6QW. Useful as a VFO or a sig generator. Thanks to all involved.
Note the cool translucent feet!
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
(21) If you add a microprocessor chip to augment some of the BITX
functions, it might be advisable to use the 10 MHZ BFO signal to clock
your uP. This could help avoid unwanted 'birdies' from the uP oscillator
getting into your BITX circuitry.
From a nice list of BITX mods:
http://kambing.ui.ac.id/onnopurbo/orari-diklat/teknik/homebrew/bitx20/modifications/LIST%20(9-24-04).txt
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Using a very nice M0XPD AD9860 shield from Kanga-UK and software by Richard AD7C I put together another little DDS VFO. This one went together without a lot of hair pulling. I put the LCD, brightness control and rotary controller on one piece of vero board -- this will also serve as the front panel.
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From: Rich
To: "soldersmoke@yahoo.com"
Sent: Thursday, January 22, 2015 9:22 AM
Subject: Cheap, open source Arduino SDR project
BillFirst, thanks for Soldersmoke and all you do for us QRP hackers around the world. I'm a big fan!
I've detected you are getting sucked into the world of microcontrollers of late. I know you are not really that excited about SDR but this is a radio that combines Arduino, the currently popular SI5351 and a Softrock to make a very functional SDR. I started this project last year which uses the fabulous Teensy 3.1 and companion audio shield. I recently packaged it all up and it looks like a QRP radio now. Still doesn't transmit but as I like to say thats "just a small matter of software".
There are several posts about it on my blog. The most recent:
There's a link to a video and a link to the code in that post.
Rock on Bill!
73, Rich Heslip
VE3MKC
Sent: Friday, January 23, 2015 4:09 AM
To:
Subject: Re: Cheap, open source Arduino SDR project
Wow Rich that is really beautiful. Amazing! I am also sending this to Pete Juliano, but I was at first hesitant about this because I feared that your combination of Si5351 and TFT display might be TOO exciting for him. Deep breaths Pete...
73 and Thanks, Bill
From: jessystems@verizon.net
To: soldersmoke@yahoo.com;
Subject: Re: Cheap, open source Arduino SDR project
Date: Fri, 23 Jan 2015 06:03:40 -0800Hi Rich & Bill,
Wow –really exciting project Rich! Congratulations and Bravo!
This is so exciting, for all hams, as this just shows the power of the available low cost technology that is now on the market. Your project is really tempting as I have a V6.2 15M softrock sitting in a box (somewhere). I was somewhat put off with the Power SDR as the opposite sideband rejection is not too good –it is clear you have cracked that nut.
Thanks for sharing Rich and yes Bill I am taking very deep breaths.
73’s
Pete N6QW
Thanks guys! When I saw the Teensy 3.1 with the companion audio codec board the first thing that came to mind was a portable SDR. Since its Arduino compatible I am able to leverage the SI5351 library, encoder library etc so its mostly just putting software blocks together. The digital filter design is a bit tricky but Loftur VE2LJX did quite a bit of work on that and now it works really well.
I hope to add CW decoding and PSK31 at some point. I've used less than half the flash on the Teensy so lots of room for new features. I'm hoping if the word gets out I won't have to do this all myself!
Pete - too bad you missed the Black Friday sale - Teensy 3.1 and the audio shield for $18. Deep breaths...
: )
73, Rich
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
This is really nice. DuWayne KQ4VB, has been talking to Pete about his use of digital chips, Arduinos and TFT displays in homebrew SWR analyzers. Obviously these techniques could be used to measure the passband of crystal filters. (Far superior to my pencil and paper procedures.) Nice work DuWayne!
Pete
Looks good, I did some playing with the TFT board I have. Did a board for the antenna analyzer using the TFT and a 9850 DDS module insted of the NOKIA and si5351. Wanted to see if there was much difference between a sine wave out and the square wave from the 5351. Appears to be very nearly the same from a couple of quick tests I have done. Want to try some different diodes and change some values for amplifier gain.
Will keep you informed. DuWayne
Earlier... (4 November 2014)
Pete
Really enjoy listening to you on Solder-Smoke. Saw the link to your
xcvr with the Adafruit si5351 board. I got a couple of them and have
been playing with code for them. Have been spending most of my time
working on an antenna analyzer based on the one by K6BEZ. Pleased to see
your article in the latest QQ. I have used basically the same circuit,
except am using the little NOKIA LCD display. The resolution is not the
greatest but works well for this application. I am using some of the
original code from K6BEZ to talk with his existing PC program. For
stand alone I have 2 modes, a straight tune mode where I can select the
frequency and read the SWR. Also implementing a sweep mode that scans
the whole band and after it is finished you can tune across and see the
frequency and SWR. I am attaching a couple of pictures of what I have
so far. Waiting on the correct op amp to arrive and making some changes
to the amp gain to get better results on the higher band where the
output of the DDS drops off.
Thanks for all the inspiration you give to us home builders and tinkerers
out here.
73 DuWayne KV4QB
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Wow, that is one beautiful BITX. Nicely done Colin. But I must say that you are exhibiting an almost inhuman degree of patience! Who needs a case? Fire that thing up and make the traditional "still-on-the-workbench" initial contact.
Hi Guys,
I loved the last SolderSmoke, it was another great episode. It really does amaze me, that a few years ago, hams were saying that it was too difficult to build your own gear that would be anywhere near to the commercial stuff, but here we are with Arduinos etc bringing powerful functionality to the masses. I couldn't have imagined building an SSB rig with a pretty and functional LCD screen when I started in ham radio.
Can't wait to get the rig built into it's case and score that first QSO.
73, Colin, M1BUU
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Wow, quite a bit of progress at M1BUU since our last look (see below). I must admit, that Arduino DDS board looks quite nice sitting there in the VFO territory. In his original BITX20 article Farhan recommends a pause before the construction of the final portions of the transmitter -- the builder is advised to sit back and enjoy the receiver that has just been created. Colin is at that point! Congratulations Colin. He has noted that his board is a bit(x) smaller than mine. Maybe he should stick with Farhan's recommendation and build the PA and driver on a separate board. This will also help prevent the dreaded oscillations -- no need to tempt fate or anger the radio gods!
Hi Pete,
Another great SolderSmoke episode this weekend, I really like the humour between you and Bill! I listened to SS whilst melting solder on my BITX project.
I'm so pleased to have got so far, and I'm very pleased with the build. That big copper clad board doesn't look so big now, but I think I have room for the TX/RX switch, BPF, RF driver, RF PA and LPF which I still need to add.
Thanks for the encouragement and advice so far, I doubt I'd be feeling so elated at this point without it!
This is going to be a really cool rig!
73, Colin M1BUU
Hi Colin,
Two words come to mind: Absolutely Superb! Wow that is such a work of art. I may never show another one of my projects as you have set the standard and benchmark.
You also have demonstrated building from the back end which we discussed in SS168. Now what you have built is a part of the test system.
Really outstanding. Be sure and video your 1st qso and share on You Tube.
Bravo!
73’s
Pete
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
With advice and tribal knowledge from N6QW and MeSquares from W1REX, Colin M1BUU, is making excellent progress on his BITX. I see that he has some territory on the board reserved for a DDS VFO. That's fine, but here's and idea for Colin and other builders: Why not build it with the standard VFO first and then add the DDS or Si570 VFO later, perhaps as an external accessory? That way you get the experience of building an LC VFO -- the full BITX experience.
Yea, it is hard to imagine Paul M0XPD as a newcomer to the hobby such a short time ago -- he is definitely now in the ranks of the esteemed digital Elmers.
And yes Colin, we do hope you avoid unwanted oscillations. Because of Farhan's great design you have a good shot at avoiding this plague. But be prepared OM. It happens to the best of us. A lot. Stiff upper lip! Never give in!
*************
Hi Bill,
I enjoyed your video about your Arduino experiment. You bet me to it! I'm really looking forward to getting my version of an Arduino powered BITX up and running.
Steady progress is being made, yesterday I added my first bidirectional amplifier to the build. I now have the mic amp, BFO, balanced modulator and first amp completed. I tested the BFO on it's own and got a respectable looking signal out of it and with a good swing below 10MHz.
Next I need to add the crystal filter, second IF amp and mixer. Pete's video will help for the mixer! BTW, I'm using the ver3 schematic but I intend to use the ver1 band pass filter.
I set out building the circuit following the N2CQR layout diagram but I've already run short on space! I do have a good excuse though, my board is smaller than yours (10"x6").
Despite my best intentions, I'm falling back towards old habits of making my circuits physically small. I'm using MeSquares in order to try and force myself to space things out a bit. I do hope that I don't end up with any unwanted coupling!
I must try hard to leave lots of space between the next bits of circuit.
I was listening to SolderSmoke 104 today and Paul M0XPD was introduced as a new ham. Little did we know that Paul would become such a big player!
73, Colin M1BUU
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Tony, G4WIF, asked about an amplifier to boost the output of the AD9850 chip. Here is Dr. Juliano's prescription:
You might find that once you plug that DDS into a circuit you may not quite get 1 V pk to pk and in fact after about 10 MHz it really starts to sag. See the attached drawing as you can put this “afterburner’ on the output of the DDS. The isolated output is good if you are interfacing with “toob” type equipment –it can be left off if you are doing SS or just left in place. This is the output from the amp and as you can see fairly clean.
73’s
Pete N6QW
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