As has been pointed out in other threads, the ESP32 micro-controller used is an extraordinarily poor choice for miners. It is made for use in very simple IoT devices such as sensors, thermostats, wearables, etc. that do not need good performance. Even the maker of them clearly states that. Even the best one only has 2 cores/threads which means that at best it can process hashes and do I/O without having to interrupt the processes provided the main and I/O threads are programmed to run independently. AFAIK the one used in the BitAxe has only 1 core...
All of that out of the way, does it work? Sure - but when there is a change of work and when it talks to the WiFi things slow down a lot. Because Skot is/was an IoT developer it makes some sense that he'd pick the ESP32 just because he is familiar with it. Unfortunately he did not know that you REALLY need a REAL multi-core/threaded CPU to ensure decent performance so the various processes running do not have to interrupt each other. Even the original RasPi-1 used a more capable chip. ref https://www.elprocus.com/difference-between-esp32-vs-raspberry-pi/
FYI, while the 1st ones from Sidehack will be using the same micro he is already redesigning it to use the Pi Nano to eliminate the processing bottlenecks and also allow using USB along with hardwired LAN connections.
edit: struckout comment on redesign.
Sorry for the long quote..All of that out of the way, does it work? Sure - but when there is a change of work and when it talks to the WiFi things slow down a lot. Because Skot is/was an IoT developer it makes some sense that he'd pick the ESP32 just because he is familiar with it. Unfortunately he did not know that you REALLY need a REAL multi-core/threaded CPU to ensure decent performance so the various processes running do not have to interrupt each other. Even the original RasPi-1 used a more capable chip. ref https://www.elprocus.com/difference-between-esp32-vs-raspberry-pi/
edit: struckout comment on redesign.
But I'll post some facts so everyone can form their own opinion;
- The average blocktime is 10 min. (600.000ms)
- My single core esp32-c3's need less than 1ms to check (including crc check/difficulty check/stale check) and submit a found nonce.
- The wireless connection has a sub 20ms latency
- Latency to the pool (solo.ckpool.org for me) including the wireless latency is around 50ms
So, according to my poor math due to the very slow esp32 I will get an additional rejected share every 12.000 submitted shares, ... I know, its shocking
In reality my rejected shares are anywhere between 1 in 750 .. 3000 shares submitted (depending on connection/pool load?).
In short: the speed of the controller does not in any way/shape or form matter. You can overload an esp32 by (mis)configuring the asic(s), but why would you do that?