I’m designing a new carrier PCB for Boron, Argon, and Xenon and would appreciate any feedback. It’s largely based on the great design from @chipmc, and as such I’ll be releasing it under the Creative Commons license once complete.
Here are the main features of this design:
- 4 separate OneWire busses, with three exposed externally for sensors
- Each of the three external ports (3.5mm headphone jack) can also be used as dry contact inputs
- External watchdog timer to reset the Boron LTE (or other Gen3 device)
- ESD protection on external OneWire interfaces
- 32KB FRAM for storage of keys and certificates
- Internal (on-board) DS18B20Z+ sensor for controlling charging current
- protection on power inputs
- Ability for the device to power cycle itself
- Pushbutton to toggle power on/off
- USB and LiPo power
- OLED 1.3" monochrome display connected to the SPI bus
I have not started the PCB design yet, but wanted to share my schematic for any input the community may have first. I welcome all comments and ideas. I’ll update the schematic based on input received here, and then post the PCB layout afterwards.
Thank you in advance for anyone who looks at this and provides comments!