#hardwaredevelopment

...one of our first Espressif chipset products.

We’re excited to get this board dialed in since we plan to use this chip in several designs!

We designed and prototyped an RP2350 Metro a few months ago, and it worked OK, but we were really short on pins, which meant a lot of annoying compromises - so we ended up only fabbing the RP2350 Feather to start. With that design flying off the shelves, It's time to revisit the Metro. We wanted to jam-pack this design, and with the extra GPIO on the B we have plenty of peripherals: the 22-pin HSTX for DVI output, Stemma QT port, NeoPixel, JST 3-SH SWD debug port, 16MB flash, an extra spot for PSRAM, MicroSD card with SPI or SDIO connections, and 5V buck converter that can give us 2 Amp easily, which we'll need since we also have a USB Host port pinout for connecting USB peripherals. We even managed to get a couple of niceties like switchable power for the USB host power, a USB boot button as user input, and an SD card detect GPIO.

OK, our 10164227-1004A1RLF (https://www.digikey.com/short/3z8mb49f) Compute Module connectors came in, so we're ready to fab this prototype of our Compute Module 4 or 5 backpack. Timon updated it to have an EYESPI connector to bring out some GPIO's and make it easy to connect small displays. There's so much packed on here; we're worried about how we're going to make a test jig for so many connectors! We may need to use an IO multiplexer to address so many pins with a microcontroller - while using a CM5 to do the test sounds 'fun,' it would not be good to have such a delicate board used for testing hundreds or thousands of these in the fabrication department.

board we are testing! With USB PD support, it's easy to plug the board into a USB C laptop power supply that can provide 20V at up to 5A - even though it's under 24V, we've found the LEDs are just as bright. Looks great, we're going to keep testing and get these boards ordered, hopefully before the year's end!

Folks love our various digital-to-analog converter boards (https://www.adafruit.com/search?q=dac). We've got a few single channels and a quad (https://www.adafruit.com/product/4470) - but what about an octal DAC? The DAC7578 (https://www.digikey.com/en/products/base-product/texas-instruments/296/DAC7578/80464) is I2C controlled, so it is easy to integrate anywhere, and 8 outputs that can be 0-5VDC. we spun up a quick breakout board so we could try it out.

is more readily available, we'll be able to have folks test this out.

On the penultimate night and New Year's Eve, we're making a quick Qwiic board—this is an I2C breakout for transparent OLED displays. We've had the display in our 'in progress' bin for a few years but finally sat down to finish it tonight. We're experimenting with a wrap-around setup for the FPC and a cutout for the display for mounting. We'll see how it goes!