Sequence controller

Eric Gunnerson has been working on a sequence controller project:

Yeah. Those pins are beautifully aligned a very precise 0.1” from where they are supposed to be…
Pro tip: Print out your design and put your components on it so that you can check the design.
Meta pro tip: Follow your pro tips.
Anyway, that’s not the only problem; it turns out that the power and LED parts of the connector are right underneath the end of the board, so you can’t use a normal header on them (you could use a right-angle one if you wanted), so I did a new revision of the board with 1.0” rather than 1.1” for the ESP and extended the board so the connectors are out on the end. That’s on the slow ship from China right now.

See the full post on Eric’s Arcana and RiderX blog.

DIY AD9833 signal generator

Daumemo has been working on a DIY signal generator based on an AD9833 IC:

In this post I am going to continue with the DIY signal generator based on the AD9833 IC where I have left in the previous part. Earlier, I have talked how I had built my first analog signal generator’s stage – variable gain amplification circuit. Usually, a generator needs to have an ability to change not only the signal’s amplitude, but also its offset. So, today I will walk you through a circuit which adds an offset to the DIY generator’s output signal.

More details on his blog. See part 1 of this series for the analog signal generator’s stage.

Arduboy with removable flash cart

A homebrew Arduboy with removale flash cart from Facelesstech:

I’ll start with the Arduboy its self. I wanted to make a small Arduboy that anyone with basic soldering skills could make. I don’t think its the easies of boards to solder but its the only way I could make it small enough and have all the features I wanted. I just went with the standard SSH1106 0.96″ screen that most people use in their homemade builds. The buttons I went with are the ones I’ve been using on my other RetroPie builds in the past. They are soft touch but they are not mushy like some are and have a small foot print.

More details on Facelesstech homepage.

Check out the video after the break.

Pogo pins + laser cutter = test fixture

Eric Gunnerson made this DIY pogo-pin test jig:

I decided to build a pogo-pin test jig, and since the approach I came up with was different than the other approaches I’ve seen I thought it would be worth sharing. I’m going to be targeting my laser cutter for fabrication, though I could have chosen to use my 3D printer instead.

See the full post on Eric’s Arcana and RiderX blog.

Check out the video after the break.

FM stereo radio receiver with RDS

Dilshan Jayakody has published a new build:

This tuner circuit is a quick prototype which I build to test the RDA5807M FM radio tuner IC. RDA5807M is a single-chip tuner IC with RDS and MPX decoder, and it equipped with I2C interface for control.
This receiver builds around Atmel’s ATmega16A 8-bit MCU. The output stage of this design consists of AN7147N, 2×5.3W audio power amplifier.

See the full post on his blog.

tinyOSD & tinyFINITY – a tiny opensource video tx with full graphic OSD


tinyOSD and the tinyFINITY,  a tiny open source video transmitter with integrated graphic OSD from

As I like fully integrated solutions I started to work on a new PCB design that includes a RTC6705 video transmitter and my tinyOSD into one tiny 16x16mm board called tinyFINITY. The image shows a preliminary version where I tested a surface mounted ceramic antenna instead of the usual wire or whip-antenna (which was rejected in later designs because of the poor performance)

Project info at  and the GitHub repository here: tinyOSD and tinyFINITY.

Check out the video after the break.

“Cigarette Pack”- 14MHz SSB QRP Micro-Transceiver


Peter Rachow (DK7IH) built a 14MHz SSB QRP Micro-transceiver into a cigarette packet size case:

This article describes the “Cigarette Pack” SSB QRP transceiver” for 14MHz that I first had mentioned some months before. Recently, when taking it from the shelf, the transceiver dropped to the floor and was severely damaged. This lead to serious defects in the front panel area, the main frame, the cabinet and so on. The interior parts were, luckily, not affected by the crash. So, I had to revise the whole radio, make a new front panel and cabinet, ply the frame straightly (as far as possible) and so on. This is the full description of the rig now to complete the files here. The good news: The radio is fine again and fully operational!  And the even better news: I still have not started smoking!

See the full post on Amateur Radio Engineering Projects blog.

Building a bluetooth DAC with Raspberry Pi Zero W


Sami Pietikainen has written an article detailing the build of his Bluetooth DAC using Raspberry Pi Zero W:

My car comes with a built-in Bluetooth hands-free but unfortunately it does not support audio streaming. Luckily there is an AUX input available which uses a regular 3,5 mm jack. Perfect opportunity for a DIY project. I built the Bluetooth DAC using Raspberry Pi Zero W and a DAC hat. This post depicts the details of this project.

See the full post on Page Fault Blog.