#husb238

USB C has a nifty power management system where, by default, you can get a classic 5V at 1A power out from a power supply or port, but with some fancy twiddling, you can request higher voltages and currents. We've always wanted a simple breakout that could get you a range of voltages using just jumper pads, but we only had a little luck with IP2721. Then we found this chip - the HUSB238 https://en.hynetek.com/pdsink.html - used in a USB-to-DC cable, which seems perfect! It can do 5V to 20V with just a resistor setting and set the current. There's also an I2C interface that can be used to set them if the settings are persistent - we'll have to try it out. There's a library here if you want to see what the registers are like https://github.com/ltyridium/HUSB238-lib. Here's our draft for a breakout design.

We wrote a driver this week for the HUSB238 USB PD sink chip https://blog.adafruit.com/2022/05/04/plug-n-play-usb-type-c-dummy-pd/ - this IC is neat in that you can either use jumpers (really, resistor selection) to set the desired PD voltage and current ooooor you can use I2C for dynamic querying and setting. we have a wall adapter that can provide almost-all-PD voltages: 5/9/12/15/20 only 18 is skipped. The HUSB plugs into the USB C cable and, over the CC lines, will negotiate the PD request and commands. For example, we can ask what voltages are available and then iterate over the options here: a multimeter displays the output voltage to prove it works! This can be a handy chip for projects where you need a lot more than 5V @ 2A power: this adapter can give up to 20V at 5A - yes 100W over USB C - and you could buck that down to get a toooon of current at 5V or 12V if that's needed. Arduino library and example code is here https://github.com/adafruit/Adafruit_HUSB238 . This is also one of the first shipping boards using an OpenAI ChatGPT assisted library https://chat.openai.com/share/d05c963d-b610-4eef-ad98-05656a33e118 https://chat.openai.com/share/a276ce74-f810-4dba-a324-e9fd1545085f