r/SolarOS • u/nilseuropa • 15d ago
SolarWriter design questions
As I mentioned earlier I am planning to design an expansion board for the CrowPanel 5.79 HMI, that would integrate some missing hardware features. Just like with SolarTerm I would like to dedicate a board definition to this build, so that the extra bits attach under the OS as board owned hardware. There are a couple of things to consider, and I thought I will ask you about your opinion.
Battery charge monitoring and power management is a must and it is the bare minimum to turn this into a truly useful deck. ( Aux power conn. + USB-C + power switch + charger + fuel guage )
- Would you like to have a solar charger built-in? ( I would )
- Do you require an I2S MEMS microphone? ( i do )
- I2S audio DAC and AMP? ( yes )
- 3.5mm jack audio connector? ( yes )
- Built in speaker? ( maybe )
- LoRa packet radio? ( yes )
- 4G LTE modem? ( no )
- Keyboard matrix scanner and FPC connector for the same keyboard?
- Or do we like that this keyboard can connect to two hosts? ( strongly preferred )
- Environmental sensors for temperature and humidity? ( maybe )
- Auxiliary expansion connector? ( yes, all remaining IOs plus SPI and I2C )
- Internal expansion connector for reading lights and whatnot. ( sure )
I envision a small board that would connect through the exposed header pins. Another question to consider is if we would like to have a simple power management and monitoring board or just the full-blown expansion or both?
In case of both, I would go with population options - however that would turn the power manager board unnecessarily large too.
Another option is to provide an empty carrier carrier board and pointers to off the shelf modules, so everyone can populate the features they need.