Live from the Desk of Ladyada

OMG, we're zooming through the backlog... new protos ordered (STC31+SHT41, MT6835) and boards/libraries shipped (Terminal Block BFF, TMAG5273, VCNL4030, MAX44009, TMF8806). Still in progress: RV-8803, WF100DPZ, ADS7128, TMF882x, and VL53L5x, then we're back to Feather designs, home sensors, and Raspi accessories.

OpenClaw wrote our 475-page uBlox GNSS library overnight. Opus suggested packed structs over byte parsing... smart. Also found new L1+L5 GPS modules on DigiKey: ~2x accuracy for $2-3 more. No RTK needed.

This week at the Desk of Ladyada, we’re comin’ back from maternity leave and getting spun up with a bunch of projects. First, a fun mailbag item: the XTEInk ‘pocket’ reader running crosspoint open firmware on an ESP32-C3. Since it’s running an Espressif chip, we could also install CircuitPython or WipperSnapper on it…a great side-effect of more off-the-shelf goods coming with ESP32 chips! See also our Yoto-hacking guide on learn.

Next, we’ve been really enjoying running OpenClaw on a Pi 5 and connecting it up to Adafruit hardware to do ‘full circle’ test-driven development. We have Anthropic Opus do the datasheet parsing and design document, then ‘farm’ out the coding work to OpenAI Codex. After the driver is written, we also have it design tests to verify hardware functionality, using other GPIO pins, NeoPixels, servos, etc., to exercise the chip capability. It’s able to run tests and then fix bugs all on its own, then text me when it needs help or to alert that it’s done. It’s very slick and fun!

Finally, using that same system of coding, we had it ‘one-shot’ a miniature oscilloscope demo for the unreleased Stemma Friend from way back (well, it took a few back-and-forths to get it just how we like). Could we have coded it by hand? Probably! But we were able to guide the development and get the look and performance we wanted in about 30 minutes of prompting while also laying in bed and chillin’ with a newborn.

We revisit the PCM5122 DAC, test hot-bar breakouts on a big Quad-Color EPD, check new prototypes, and explore linear image sensors

This week we designed some prototypes: CAN FD version of our FeatherWing and BFF.

We also designed a board for the AP33772S (https://www.youtube.com/watch?v=ngQT0Et32wM) which we covered on EYE ON NPI - this is a chip that can do extended range USB Type C Power Delivery (https://www.usb.org/usb-charger-pd) and it seems, Programmable Power Supply mode (https://hackaday.com/2025/03/24/pps-is-the-hottest-usb-c-feature-you-didnt-know-about/).

Might also do one for the AP33771C (https://www.digikey.com/short/022nd0fp) too with li'l switches like our HUSB238 (https://www.adafruit.com/product/5991).

We also wrapped up the STHS34PF80 driver (https://github.com/adafruit/Adafruit_STHS34PF80) and we'll have a breakout for that shortly once we get chips on order.

And on The Great Search: CAN-FD update to MCP2515

This week we got Claude working natively on Windows (yay!) which speeds up development since we're not hitting the filesystem through multiple layers.

That meant we also worked on a bunch of little breakouts: the BMP585 protos came in and those worked fine. Plus we knocked out the VEML6046 RGB+IR sensor library (https://github.com/adafruit/Adafruit_VEML6046) and started work on a few others.

It turns out the bq25628e (https://github.com/adafruit/Adafruit_bq25628e) was not what we wanted in a charger, because ILimit doesn't affect the charge rate, which is like 40mA by default - boo! We'll find another alternative and also try to get back to that bq25798 (https://github.com/adafruit/Adafruit_bq25798) solar charger shortly.

We also worked on the e-Ink bonnet, which worked great as rev A and only needed some pinout swaps - thanks to BlitzCity for updating the CircuitPython-api EPD library (https://github.com/adafruit/Adafruit_CircuitPython_EPD) to add support for the bigger 7.5" & friends which we verified on Raspberry Pi and also the Particle Tachyon - speaking of which we are getting Blinka support into main for that board! (https://github.com/adafruit/Adafruit_Blinka/pull/1001)

And on The Great Search - 24-bit I2C ADC Chip for RTD sensors

#circuitpython #sensorhacks #thegreatsearch

Fresh drivers for Bosch BMP5xx sensors & LiPoly chargers, plus Particle Tachyon fun with web-console shell + Blinka support! Also, heat sink tips for TO-220s.

This week at our desk we cranked through a whole mess of drivers. Starting with the BMP580/BMP581/BMP585 series, which had a proper Bosch driver library (https://github.com/boschsensortec/BMP5_SensorAPI) so we wrappered it with Claude (https://github.com/adafruit/Adafruit_BMP5xx) to make a nice Adafruit-y library with I2C/SPI and IRQ support. We plan to stock all three variants of the chip since the driver is the same for all.

Then we cranked through the bq25628e (https://www.digikey.com/en/products/detail/texas-instruments/BQ25628ERYKR/21298592) which is a nice buck-mode LiPoly charger with I2C monitoring and up to 2A rate - the I2C driver (https://github.com/adafruit/Adafruit_bq25628e) was kinda long but it's nice to have monitoring built in so no separate lipoly gas gauge is needed. we're using this as practice while we try to get through the bigger/more complex bq25798 (https://www.digikey.com/en/products/detail/texas-instruments/BQ25798RQMR/15666783) driver (https://github.com/adafruit/Adafruit_bq25798).

We also got more time to play with our Tachyon: one thing that is really impressive is the web-console shell access! It solves a common issue with Pi's where getting initial access can be frustrating. Using the PiStemma (https://www.adafruit.com/product/6365) and the Crickit instructions (https://developer.particle.io/tachyon/accessories/adafruit-crickit-hat) we are able to get Blinka + CircuitPython libraries going. We'll get those mainlined next week!

And on The Great Search: TO-220 Heat Sink: https://youtu.be/uyvxSyJLR00

Last week, we conducted a Great Search for a clear shaft linear potentiometer. This week, the prototypes arrived—and they work great!

We're also beginning work on the FruitJam Tester. We'll be showing the finalized silkscreen, the cover plate we designed, and the expected form factor of the tester itself.

Additionally, we wrapped up a library for a QMC5883 breakout. This chip serves as a drop-in replacement for the now-discontinued HMC5883. It's frequently found in quadcopter builds, so we thought it would be a great candidate for a simple magnetometer breakout.

This week at the desk, we tackled a huge stack of E-Ink displays. A couple of weeks ago, we focused on restocking the tricolor and grayscale 2.13" and 1.54" models. This time, we worked on the 2.9" version for the MagTag and explored some larger, very cool display options: https://github.com/adafruit/Adafruit_EPD/pull/86.

We got most of them working! A few were tricky—some had hot-bar connectors (so we designed an adapter), and one had a flipped connector with some lingering code issues. It'll get sorted out, just wasn't as plug-and-play as the rest.

We also started a new project to showcase the SynthIO library in CircuitPython—more on that soon!

Ladyada's diving into solar charging tech with the bq25798 MPPT charger ☀️, exploring IR sensors, drone-friendly compasses, and prepping for another big release ... but take it easy, take it slow ...baby steps

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