ESP-Miner

ESP-Miner is bitcoin miner software designed to run on the ESP32. It mines on ASICs such as the Bitmain BM1397. The BitaxeMax is a handy board for this!

Architecture

• Uses the ESP-IDF Framework, which is based on FreeRTOS (no Linux involved)
• Uses the ESP32 WiFi to connect to the network
• The ESP32 is provisioned to the local WiFi over BLE using ESP SmartConfig

Firmware

• ESP-Miner connects to and verifies the attached mining ASIC.

  • Setting the baud rate, hashing frequency, and filling in some other mystery registers
  • This startup-sequence for the BM1387 and BM1397 can be found in cgminer the Kano edition in driver-gekko.c

• ESP-Miner connects to your pool or stratum server and subscribes to get the latest work.

  • This is done with JSON-RPC
  • Via the Stratum protocol

• ESP-Miner the latest work and formats it to be sent to the mining ASIC.

  • There isn't much change here except for computing the midstates, and shifting some bytes around
    • Beware of endianess!
    • How do we do this? Examples in cgminer Kano edition.

• ESP-Miner sends this work to the mining ASIC over serial.

• The Mining ASIC will report back any when it finds a hash over the difficulty (which)?

  • The catch here is that if it doesn't find a hash over the difficulty, it will not report back at all. So you need to keep track of the hashing frequency and the time so that you can send a new block header to be hashed.

• ESP-Miner will report back to the pool over Stratum the results of mining.

• All of the administrative stuff of running a miner like;

  • Set the BM1397 core voltage and current.
  • check the fan speed
  • check the BM1397 temperature
  • optimize the hashing frequency and core voltage for max efficiency