Crypto Tracker
to flash firmware
esptool.py --port <COM PORT> write_flash -fm dio 0x00000 firmware.bin
https://www.echotwek.com/wp/2017/11/03/real-time-litecoin-ticker-gdax/
- v1.1 - add support for eth and btc
- v1.2 - only subscribe to one coin at a time because the number of websocket messages was adding a delay to the price