# Notes

## Boards

- Raspberry Pi Zero 2 W - cheapest option
  - No battery charging
  - Consumes more power even if it had a battery

- ItsyBitsy M4 Express w/ WiFi
  - Can get the M4 via the Hack Club store
  - WiFi (Bitsy AirLift) is $15 from AdaFruit, can also be bought on Digikey
  - WiFi uses a lot of power relatively
  - No battery charging
- Adafruit nRF52840 Feather ([link](https://www.adafruit.com/product/4062)) ([digikey](https://www.digikey.com/en/products/detail/adafruit-industries-llc/4062/9843410))
  - $25
  - Has Bluetooth - lower energy
  - Has battery charging built-in

## Displays

- [Various E-ink displays from Adafruit](https://www.digikey.com/en/products/filter/evaluation-boards/expansion-boards-daughter-cards/797?s=N4IgjCBcpmAMVQGMoBcBOBXApgGhAPZQDaIALABxgDM1ArCPtWbQOwCcjIztVXP1CgCZ%2BLQdVG8AbFzLshrOpyZiKZSYNayhdMFPUreDQ4IpddZIWQj4qdMnRn4HNKU-JV2cTgF18AB1QoEABlDABLADsAcxAAX3wAWghoEBRIDBx8IkhSMDohMx84hJAZVPCAE2DkuBsQQOCuVABPf2xggEMAZxQSoA)
  - 2.13" tri-color looks promising
  - Or monochrome (more colors vs faster update speeds)
  - NVM *BAD OPTION*: 3-15 seconds for updates (monochrome vs color), 3 minutes between full refreshes
    - I don't want to have to code carefully around doing full refreshes
    - And 3 seconds even isn't great, but is usable
- [OLED display with controls](https://www.adafruit.com/product/3531)
- [OLED display with 3 buttons](https://www.adafruit.com/product/4650) ([digieky](https://www.digikey.com/en/products/detail/adafruit-industries-llc/4650/13170952))
  - 10mA power draw
  - Any leftover buttons can be user-assignable

## Controls

- Joystick things
  - [Joystick with button](https://www.adafruit.com/product/512)
  - [Slim joystick](https://www.adafruit.com/product/2765)
    - [Breakout board](https://www.adafruit.com/product/3246)
  - Similar: [PSP 3000 joystick](https://www.adafruit.com/product/444)
    - Easier to mount?
  - [5-way switch](https://www.adafruit.com/product/504)
    - [Cap](https://www.adafruit.com/product/4697)
- Possible control scheme:
  - Menu/list system
  - Up and down to go through the list
  - Click certain button to engage with sub-menu (like a slider or something)
  - Left and right to go in and out of sub-menus
  - Another button to click in sub-menu

## Other

- Headers:
  - [Short female headers](https://www.adafruit.com/product/2940) ([digikey](https://www.digikey.com/en/products/detail/adafruit-industries-llc/2940/5848449))
  - [Short male headers](https://www.adafruit.com/product/3002) ([digikey](https://www.digikey.com/en/products/detail/adafruit-industries-llc/3002/6827172))
- Batteries:
  - [18650](https://www.adafruit.com/product/1781) - can make a triangle shape so it sits nicely in my desk, 2200mAh (lasts ~36 hrs)
  - [flat lipo](https://www.adafruit.com/product/3898) - flat and small (lasts ~7 hrs)

## not final but somewhat thought-out and researched plan

- nRF52840 Feather
- 128x64 OLED FeatherWing
- Some kind of joystick
- Headers, obviously
- 3d print some decent caps for the buttons