SolderSmoke Daily News: Arduino

Showing posts with label Arduino. Show all posts

Saturday, March 28, 2015

SolderSmoke Podcast #174:Belthorn III, BITX20(-40), Parasites, Test Gear, Hamfest, SPRAT, Flares, BITX History

SolderSmoke Podcast #174 is available:

http://soldersmoke.com/soldersmoke174.mp3

March 28, 2015

Happy Arduino Day!
Pete's Belthorn III Transceiver (with cool color display)
Bill's BITX 20 (that used to be a BITX20/40)
AD9850 DDS added to Barebones Superhet
Jean Shepherd on Parasitic Oscillations, Obsession, and Madness
Simple Test Gear for the Homebrewer
Digital Oscilloscopes and their amazing capabilities
Dongles and other great stuff in SPRAT 162
The BIG St. Patrick's Day Solar Flare
VK6MV's Amazing Rhombic (+)
VK7XX (Dos Equis!)
A Bit of BITX History
Pete going KX3 QRO

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Friday, March 27, 2015

March 28 is Arduino Day 2015!

Dave W2DAB alerts us to tomorrow's celebration of World Arduino Day. https://day.arduino.cc/#/

Dave says the events often produce some interesting video.

We will attempt to participate by doing something Arduino-ish during SolderSmoke 174, which is scheduled for tomorrow.

Forza Banzi! Viva Arduino!

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Tuesday, March 24, 2015

A Box Filled with DDS

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.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Thursday, February 26, 2015

A Really Cool Idea: Use your BFO as your Arduino DDS Clock


(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

Thursday, February 12, 2015

Pete and Ben's "Let's Build Something" Reference Page

Lots of tribal knowledge here! That's the direct conversion receiver that forms phase 1 of Pete and Ben's "Let's Build Something" project. Arduinos! Si5351s! AD9850s! And it will morph into an SSB transceiver. Check it out:

http://www.jessystems.com/LBS_Detail.html

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Saturday, February 7, 2015

DuWayne's Scalar Network Analyzer -- In an Altoids Tin!

DuWayne (KV4QB) has done something very cool here. He's taken an Arduino Nano, a cheap AD9850 DDS board, a small screen, and a couple of log detectors, and he has built IN AN ALTOIDS TIN a scalar network analyzer that lets you see the bandpass of a filter. (We posted an earlier version of this here: http://soldersmoke.blogspot.com/2015/01/duwaynes-ad9850-arduino-tft-swr-scanner.html ) Wow. I've been doing this by hand, changing the input freq at 100Hz increments, measuring the output, putting the results into a spread sheet, converting to log (db), creating a graph... DuWayne makes it a lot easier. DuWayne is being encouraged to write up the results, possibly for QRP Quarterly.

Hi Guys
Started playing around with the SWR scanner that I had been working on. Waned to see how hard it would be to make a very simple scalar network analyzer out of what I had. Really wanted something small to use for checking bandpass other filters. Hoped to get about 30 db. of range ,which should be enough for most filters. I have a couple of 8307 log detectors, but was afraid that it would be a pain getting it working and shielded in an Altoids tin along with the rest of the circuitry. Went with something even easier than the resistive SWR bridge I already had. Replaced the bridge with two basic diode RF probes, and changed the amplifiers so I could adjust the gain. I use one to measure the direct output of the 9850 DDS module, and the other for the output of the device under test. Kept the same control function as in the SWR scanner. A short push on the encoder button starts a sweep of the selected band. Holding it down for over a second cycles through the bands. Once a scan is done you can use the encoder to scroll through the sweep. I display the frequency and iDUT value in db relative to the output of the DDS module. The USB connector is available and different start and stop frequencies can be entered if needed when working with IF stages.

Well it worked much better than I had expected. After a simple adjustment of the amp gains with the output looped directly to the input, I was getting nearly 50 db with the loopback removed. Just using some standard value resistors, in a pi attenuator I got a very nice looking sweep that was within a couple db of the 40 db i had built it for. Since I only used standard value resistors, I though this was good enough.

Then I used ELSIE to design a 14mhz lowpass filter, again used standard values for L and C that I had on hand . Really happy with the results I got.

Finally I grabbed 3 crystals out of a bag without checking frequency or other parameters, I threw together a basic crystal filter. Used the USB interface to set the sweep range, I was really really really pleased with the results I was able to obtain.

The software still needs a little tweaking and a couple of additional functions I want to add, but I think this will be a very nice tool. Plan on giving it a try when I build Pete's Lets Build Something transceiver. Amazing what you can stick in Altoids tins, even if you have to stack two so you can include a battery pack .

Attaching some pictures of the progress so far. As you can see that with what I used to build the test fixtures, I am amazed that they even worked at all.
73 DuWayne

Saturday, January 31, 2015

SolderSmoke #171 DC RX in QQ, Power Supplies, Small Screens, 12 Buck Counters, HW8 Error?, KX3 RX

SolderSmoke Podcast #171 is available:

http://soldersmoke.com/soldersmoke171.mp3

Bench Report:
Pete's Small Screens (in Color!)
Si5351s
Bill's Graph Paper Frequency Readout
Bill's Broadened Barebones Barbados RX. DIGITIZED!
Another AD9850 DDS using M0XPD Kanga UK Shield
New 13 dollar Color Display (Prettier than Graph paper!)

Pete and Ben's Article in QRP Quarterly Available free here:
http://www.qrparci.org/qqsample/qqsample.pdf

The DEEP SPIRITUAL REWARDS of DC Receivers
The Importance of Good Power Supplies
SPRAT Article on HW8 Design Error
Latest Edition of Hot Iron
Elecraft KX3 -- Has one of the best receivers in the world

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Wednesday, January 28, 2015

Back Into the Digital Morass

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.

Monday, January 26, 2015

New Analog Frequency Readout for BITX17 VXO

I've been getting tired of being in the dark about the frequency on which my BITX17 was operating. So I pulled out some graph paper, my frequency counter, and a pencil. You will see two frequencies at each point -- that's because I use two crystals, switched by the black knob on the left. I realize this paper and pencil approach is hopelessly out of date, but I see it as "appropriate technology" for a discrete component all-analog transceiver.

Pete set me straight on how to come up with the numbers: VXO frequency minus ACTUAL carrier oscillator/BFO freq. After doing this I took great delight in going on the air and asking guys with fancy "glowing numerals" rigs to compare their freq readout with my pencil and graph paper readouts: they were painfully close.

But I am not slipping completely into stubborn Luddite-ism; this weekend I worked on a DDS-based AD9850/Arduino VFO with I-Q output based on Paul M0XPD's Kanga-UK Arduino Shield. STAY TUNED!

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Saturday, January 24, 2015

VE3MKC's Teensy Si5351 SDR Receiver with a Tiny Color Screen (video)

From: Rich

To: "soldersmoke@yahoo.com"
Sent: Thursday, January 22, 2015 9:22 AM
Subject: Cheap, open source Arduino SDR project

Bill

First, 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:

http://rheslip.blogspot.ca/2015/01/teesy-sdr-project-update.html

There's a link to a video and a link to the code in that post.

Rock on Bill!

73, Rich Heslip

VE3MKC

From: solder smoke

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 -0800

Hi 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

Jan 23 at 9:27 AM

Pete Juliano
me

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

VE3MKC

Friday, January 23, 2015

DuWayne's AD9850 Arduino TFT SWR Scanner

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

Sunday, January 18, 2015

Digitizing the Barebones Superhet

I did this for Pete. And I did it to start out the new year with something different. And because I needed the crystal for my beloved BITX and didn't want to buy more crystals.

After successfully broadening the filter in my Barebones Barbados Superhet (originally built by Dale Parfiit W4OP) I decided to replace the VXO with an outboard Arduino/DDS device. Nothing new in that (I was playing with this back in October), but in what I think is a symbolically significant twist, I pulled out the tuning cap for the VXO and, in the hole left by the tuning control, replaced the knob with a BNC connector. That connector now carries DDS signals into the receiver. The crystal was at around 23.125 MHz -- that's why the LCD display is showing 23 MHz.

It works great. I was listening to the DX station in Iran this morning.

Here is a video of the October 2014 experiments:

Saturday, January 17, 2015

Colin Finishes His BITX

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.

Bill, first regens, now SDRs? Amazing! I exchanged a few words with George Dobbs about your change of heart towards regenerative receivers, he seemed genuinely pleased. :)

Pete, your Si5351 work with the pretty displays is cool, I can see me getting pretty hooked! I have the Si5351 board, Paul M0XPD advised me to buy it. I'd love to build another SSB rig in a smaller box for regular SOTA activating. I must look into the pretty little displays and have a play with the Si5351. I notice that Hans Summers has now put out a cheap Si5351 based kit, handy for us guys in Eu. http://www.hanssummers.com/synth.html

I finished building my BITX board yesterday but wanted to have a sleep before applying power! Today I carefully checked the circuit for errors and found none, phew! I fired the rig up gently, watching the current carefully. I wound up the TX bias to 50mA as stated in the MKARS80 instructions, all went well. I plugged in the mic and spoke - BANG! - Everything went off. Oops - I had used a 500mA fuse for initial safety and forgot to swap it for the bigger one! I fitted a 1.6A fuse and hey presto, all was fine. I was absolutely amazed and to be honest, rather proud of myself. I think the TX is a little bit too hot, my meter is showing about 6W on voice peaks- eek! The rig seems to be perfectly behaved though, no wierd effects seem to be happening. I can just turn the bias down a bit, right?

Anyway, I was happy with my progress so I finished for the day. I still need to investigate and probably tweak the carrier suppression.

I spent a short while talking into a dummy load, using my FT817 to monitor the transmission. My 2yr old son was interested in my voice coming out of the 817'sspeaker!

Thanks for all the guidance and help along the way, I'm elated that I've built a voice rig that works! I've attached a pic of my finished board, I only just squeezed the circuit on, but isn't she pretty? :-)

Can't wait to get the rig built into it's case and score that first QSO.

73, Colin, M1BUU

Wednesday, November 26, 2014

Colin's BITX is Receiving!

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 had really wanted to get my BITX working as a receiver before the end of the weekend, but Lewis Hamilton and his (successful) bid to become Formula 1 World Champion, put an end to that idea! I also decided that I wanted to buy some better quality capacitors for the band pass filter, so I've ordered them today.

I fired up the receiver chain for the first time this evening from where the BPF should be, right through to the AF amp, I'm pleased to report that I seem to have created a working superhet receiver! I heard some BC breakthrough at certain points of the tuning range and the rig receives the second harmonic of my Rishworth Buildathon 40m transmitter beautifully (on right part of dial too!). I hadn't tested the RX IF amps or AF amp before, but they seem to be doing just fine.

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

Tuesday, November 18, 2014

Pete's Video on Connecting Arduinos and DDS chips (video)

After watching all Pete's work with the smaller Arduinos, that Uno R3 board seems HUGE. That's what I should stick with. Great idea using those robust terminal strips. Thanks Pete.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Monday, November 17, 2014

Pete and Ben's "Let's Build Something" Direct Conversion Receiver

This direct conversion receiver is part of the "Let's Build Something" project of Pete N6QW and Ben KK6FUT. Publication will be in QRP Quarterly late in January 2015. Pete reports that the front panel is a piece of galvanized sheet metal from Home Depot –total cost 82 cents.

Thursday, November 13, 2014

Colin's BITX

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

Wednesday, November 12, 2014

DDS amplifier

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

Tuesday, November 11, 2014

Digitizing my BITX17 with an Arduino and an AD9850 chip

This is only temporary! My analog, discrete, hardware-defined BITX17 was NOT harmed or even modified for this little experiment.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Monday, November 10, 2014

Background on the use of Si5351 -- code and integration with Arduino Nano (video)

I somehow missed this one. Here Pete talks about how the use of the Si5351 in ham radio has been evolving, who has been working on it, etc.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20