encounters with electron•ics

Hammond-boxed sensor board with STM32 L0x1

The next step after L0x1 development board: STM32L0x1-based sensor board. Same schematic, but on a PCB which matches Hammond 1551GBK box, with a CR2032 battery holder.

A bit of through-hole fun (with MSP430), part II

Second installment of adventures in MSP430. A Hammond-boxed MSP430G2553-powered sensor board, with RFM69 radio, intended for running mecrisp forth.

stm032l041f6 + rf69 'dev sensor' board

While jeenode zero is a smashing board, I wanted to see if I can go for a little smaller and cheaper MCU in the actual environmental sensors I have around the house. Hence this "quick-and-dirty" "development board" with STM32L041F6P6 (TSSOP-20 package, 32kB flash, 8kB RAM), RFM69CW radio, basic assortment of LED+BOOT button+RESET button, and the pins broken out.

(Another) FT231X USB-to-serial

I already have so many USB-to-serial boards... but of course I had to try to make another one myself. I went for FT231XS chip, and tried to pack in all the features I ever wanted: selectable 5V/3.3V/no supply; proper 3.3V regulator, limiting i/o levels to 3.5V max but down to whatever the target has, compact layout.

A bit of through-hole fun (with MSP430)

I re-discovered that MSP430 exist and are smashing, especially with mecrisp forth. First installment.

Pocket Beagle RFM69 cape

A half-mounted Pocket Beagle cape with RFM69 radio, atmega328p, RTC, atsha204, a few status LEDs, and a JST connector for Pocket Beagle backup power.

Serplus shield for the bat board

I've made a shield for the bat board (a "batshield") to turn into an F072-based SerPlus, with some extra features: "raw" mode (works as any other USB-to-Serial with DTR), neopixel for status, FET to control output power, slide switch to select 3.3V adn 5V).

The bat board - a breakout for STM32 in LQFP48

I like the size of the ARM Teensies, and I've seen (and tried) a STM32L4 breakout of this size here: Dragonfly. However I wanted something cheaper, simpler, and hand-solderable (as usual). Hence a breakout board I dubbed "the bat board" (because I'm not good with names).
Note: Main post on the main page.

ARM breakouts

A summary of hand-solderable ARM breakout boards that I've made over the past year (STM32F042F6P6, STM32F030F4P6, MKL27Z256VLH4).

BBB-RFM69 (Beaglebone Black radio half-cape)

A BeagleBone Black half-cape featuring: an atmega328p, a RFM69(H)W radio and a DS3231 RTC with battery backup.

X-A4U-stick rev2

Following up on X-A4U-stick rev1, I've made another revision of the board, again Open Hardware.

NOTE: The content of this post is pretty much the same as the main project page.

X-A4U-stick rev1

Delving into the world of designing PCBs and SMT soldering, I've made an USB stick with atxmega128a4u, microSD socket and a couple more goodies.

Remarks about soldering tinyUSBboard rev4 (SMT) kit

This post is about soldering matrixstorm's tinyUSBboard rev4 - you can get a kit at Tindie for an incredible price of $4.

A microSD + crypto shield for AVR stick

A shield for Stephan's fantastic AVR stick is in the works! It has the same format as the AVR stick itself, 5cm x 2.5cm. I want to use the AVR stick as an encrypted "mass" storage, so the features are

Encrypted USB stick with atxmega128a3u

Stephan Bärwolf's AVR stick is a wonderful device to play with: it is a breakout of sorts for ATMEL's atxmega128a3u chip, and I like how it is designed:

JeeNode Micro with TMP102

I bought a TMP102 breakout, made by Sparkfun and soldered it onto my JeeNode Micro.

Notes on programming JeeNode Micro with Arduino

Having gotten a JeeNode Micro (with a RFM69CW instead of the usual RFM12B), I needed to figure out a way to program it from Arduino GUI. A Bus Pirate from Dangerous Prototypes came in really handy:

RFu-328 with RFM69CW and Thermistor coin cell board

As I've been moving from Ciseco's radios to HopeRF's RFM69CW's, my XRF + thermistor sensor from Ciseco needed to be "converted" as well. As RFµ-328 has the same footprint as XRF (except it's "sticking out" from the pins at the other end), with similar pinout (GND, VCC and some input/output pins at the same places), I thought that I would just replace the XRF with a RFµ-328 with a proper firmware. Success!

From Ciseco to HopeRF

Recently there were several things related to Ciseco that annoyed me a bit (RFµ-328 is going to get a bigger footprint; they removed an item from a bundle in their shop from one day to the next without changing the price or announcing anything; buying SRF radios can be now only in bulk (10 minimum) UPDATE: Ciseco rescinded the decision; SRFs are available individually again. Well, too late for me.). Don't get me wrong, they still make cool stuff (like the RFµ-328), but I didn't want to depend on them for radio modules.

USB tester

Inspired by FriedCircuits' USB Tester 2.0, I've decided that instead of ordering one, I'll make one myself on a protoboard.