jugando con Arduino

youtu.be/y0mCjXQiuFI?si=AMafwN…

#arduino #si5351 #ham #radio #radioaficionado #vfo #dds

Arduino
iniciando
v2024.12.29

vm.tiktok.com/ZMkBnyQCx/

#arduino #SI5351 #ham #radio

A Super-Simple Standalone WSPR Beacon https://hackaday.com/2024/06/14/a-super-simple-standalone-wspr-beacon/ #amateurradio #transmitter #radiohacks #weaksignal #atmega328 #digital #beacon #si5351 #wspr #gps #ham

Also called a “DDS VFO.” This may be a bit of a brain dump. Although I have local notes (in Joplin), if I had to look hard for this stuff, maybe someone else can benefit from it. I’ll try to skip the details of the dead-ends I went down.

I put the Pixie kit I put together as a distraction from the thing that’s been bugging me, which is putting together some different modules in a receiver to 1) learn more about hardware and b) eventually design a radio orienteering receiver. (Why design when I can put together someone else’s design? Not sure yet.)

Building

In short, I took these building blocks and put them together:

• Adafruit Si5351 breakout board to act as a local oscillator
• Adafruit Metro microcontroller development board
• Pretty generic OLED display (pulled from a TTGO T-Beam I originally got on AliExpress)
• Arduino code from CesarSound
• Pixie kit from AliExpress
• Rotary encoder with push button from eBay
• Generic momentary contact button (originally from SparkFun kit)
• High-pass filter that I designed and need to blog about

Although I don’t understand it all yet, the modification to the Pixie is explained at the very end of this “S-Pixie QRP Kit Student Manual.” Although I have the Pixie and not the S[uper]-Pixie, the component names matched the schematic I was provided with.

The S-Pixie can be modified to cover the whole 40 Meter band by replacing the oscillator with a VFO. A popular approach has been to use a Direct Digital Synthesizer (DDS) controlled by an Arduino. The human interface includes an LCD display and rotary encoder.
Popular DDS choices include the AD9850 and the SI5351.
Remove/Omit C3, C7, Y1, W1, D2, R6, and C8.
Place a 47K resistor between Q1 base and GND.
Connect the DDS across that resistor.

I don’t think I changed any of the code yet, but my version is here. I used the same pins CesarSound defined in the schematic below. I only used the connections from the Si5351 module, the OLED display, and the rotary encoder to the Arduino and ignored the rest. I skipped the capacitors across the rotary encoder connections.

Testing

I’m a bit overwhelmed, so you don’t get anything here right now.

here is where I talk about testing, maybe with audio/video

does it transmit

HPF to block broadcast AM – separate blog post

not great selectivity – hard to use for QSO

Next Steps

I have to keep reminding myself that this is not a product, it is a learning exercise. I do plan on making a standalone digital VFO module (with a board and case and all that) that can be plugged into other modules as needed. The digital VFO might use something smaller and cheaper than the Metro, like an ESP32 dev board, if I can get it to work. Pete N6QW has a bunch of information on this type of project.

The Pixie part may be modified/stripped down more so I can better understand it or re-use into another application.

Photos

https://w1cdn.net/2024/02/pixie-with-digital-vfo/

#arduino #hamRadio #homebrew #kit #pixie #si5351 #vfo

Проект «Селенит». Часть 4: Квадратурный гетеродин

Одной из самых труднореализуемых задач в конструировании радиолюбительской аппаратуры связи всегда была разработка и наладка частотозадающего оборудования. Радиолюбителям для работы в эфире выделены достаточно узкие полосы частот, да ещё и тонко «порезанные» изнутри на участки с разрешёнными видами модуляции. Работа на передачу за пределами разрешённых диапазонов радиолюбителям разрешена только в исключительных случаях, например, при спасении терпящих бедствие. Из этого следует, что ещё до переключения в режим передачи нужно быть уверенным в том, что сигнал передатчика не выходит за границы разрешённого диапазона, в момент переключения режимов не будет «сдвига частоты», а во время передачи не произойдёт её «выбег». В современном мире все эти условия выполняются применением аппаратуры с кварцевой стабилизацией частоты. Не является исключением и представленный в публикации трансивер. Все части цикла статей о создании любительской радиостанции: Проект «Селенит». Часть 1: Побуждение к действию Проект «Селенит». Часть 2: Квадратурный смеситель Проект «Селенит». Часть 3: Диапазонный полосовой фильтр Проект «Селенит». Часть 4: Квадратурный гетеродин ← Вы здесь

https://habr.com/ru/companies/ruvds/articles/772210/

#ham_radio #sdr #si5351 #системы_связи #схемотехника #ruvds_статьи

I'm building a #WSPR transmitter using a #Nodemcu controller, #SI5351 clock generator and GPS module for precise timing. I testet the prototype today. The HF PA uses three BS170 mosfets in parallel and is driven from the 3.3V of the Nodemcu. I did a quick check with my thermal camera. Temperature reading of the BS170 is 75 degree C after 20 seconds. But the more concerning temp reading comes from the Nodemcu having hotspots in the 100° C range. Not good.
#hamradio #diy #electronics

Altoids Tin Spy Radio Goes Solid State https://hackaday.com/2023/09/21/altoids-tin-spy-radio-goes-solid-state/ #amateurradio #transceiver #RadioHacks #oscillator #lowpower #SI5351 #ham #QRP

Clock Hack Gives DEC Rainbow a New Lease on Life https://hackaday.com/2023/09/12/clock-hack-gives-dec-rainbow-a-new-lease-on-life/ #Retrocomputing #retrocomputing #ArduinoHacks #Rainbow100-B #oscillator #pacemaker #arduino #SI5351 #Parts #clock #DEC

Retro and New Tech Combine in this Hybrid Ham Transmitter

We've said it before and we'll say it again: the best part about holding an amateur radio license is that it lets you build and use your own transmitting equipment. Hams have been doing this for more than a century -- indeed, it was once the only way to get on the air -- using whatever technology was available. But the mix of technologies in this low-power transmitter for the 80-meter band is something you don't see every day.

As ham [Helge Fykse (LA6NCA)] describes in the video below, the project began when he came into possession of a bonanza of vacuum tubes -- 12A6 tetrodes, specifically. The new-old-stock tubes were perfect for an RF power amplifier, but that left the problem of what to use for an oscillator. [Helge] chose to meld the old with the new and used oscillator board that he designed. The board has an ATmega88 microcontroller and an Si5351 oscillator, along with a 3V3 regulator to let the module run on 12 volts. And for a nice retro touch, [Helge] put the board in a 3D printed case that looks like an old-fashioned quartz crystal.

There are some other nice design touches here too. A low-pass filter cleans up the harmonics of the oscillator's 3.5-MHz square wave output before feeding it to the amplifier, in a nod to proper spectrum hygiene. The primary for the amp's air-core output transformer is hand-wound, with 3D printed spacers to keep the winding neat and even. The tuning process shown below is interesting, and the transmitter was used to make a solid contact with another ham about 100 km away. And we really liked the look of [Helge]'s shack, stuffed as it is with gear both old and new.

We've personally tried the Si5351 for QRP transmitters before, but this blend of the old and new really makes us want to find some tubes and get to playing.

Thanks to [Stephen Walters] for the tip.

#radiohacks #12a6 #amateurradio #atmega88 #ham #qrp #radio #si5351 #transmitter #vacuumtube #valve

Arduino Becomes Superhet with a Little Help From Friends

A radio receiver is always a fun project. [Jayakody2000lk] decided that his new superheterodyne design would use an Arduino and it looks like it came out very nicely. The system has four boards. An off-the-shelf Arduino, a Si5351 clock generator board (also off-the-shelf), and two custom boards that contain the IF amplifier and mixer.

The receiver started out in 2015 without the Arduino, and there's a link in the post to that original design. Using the Si5351 and the Arduino replaces the original local oscillator and their have been other improvements, as well. You can see a video about the receiver below.

Tuning is by a rotary encoder and the current software lets you tune from about 4.75 MHz to a little over 15.8 MHz. Of course, you could change to any frequency the Si5351 can handle as long as the mixer and other components can handle it. The IF frequency is the usual 455 kHz.

If you decide to build this yourself, the design files are on GitHub. Overall a very nice and neat design. We are always amazed how little radio architecture has changed since Edwin Armstrong's day. Of course, we have better components, even if they aren't meant for radio purposes.

#arduinohacks #radiohacks #arduion #si5351 #superhet #superhetrodyne

The Simplest FT8 Transceiver You’ll Ever Build

Probably the most interesting facets of amateur radio in 2021 lie in the realm of digital modes. Using the limitless possibilities of software defined radios has freed digital radio communication from the limits of what could be done with analogue electronics alone, and as a result this is a rare field in which radio amateurs can still be ahead of the technological curve. On of these newer digital modes is FT8 created by the prolific [Joe Taylor K1JT].

And it's for this mode that [Charles Hill] has created an easy-to-build transceiver. Its brains are aTeensy 3.6, while the receive side is a Si4735 receiver chip and the transmitter is a Si5351 programmable clock chip driving a Mini-Circuits GVA84 power amplifier with an appropriate filter. The interface is via a touchscreen display. It relies on existing work that applies a patch on-the-fly to the Si4735 receiver chip for SSB reception, and another project for the FT8 software.

The charm of this transceiver is that it can be assembled almost in its entirety from modules. Some radio amateurs might complain that homebrew radios should only use the most basic of components assembled from first principles, but the obvious answer to that should be that anything which makes radio construction easier is to be welcomed. If the 100 mW output power seems a bit low it's worth remembering that FT8 is a weak signal mode, and given the right propagation conditions the world should be able to hear it despite the meagre output.

We've featured quite a few radios using the Si47XX series, which can be made into very tidy receivers indeed.

#radiohacks #amateurradio #ft8 #si47xx #si5351 #transceiver