ESP8266 Community Forum

- Wed Mar 23, 2016 3:58 am #43856 @lethe - your results don't surprise me. I've also found issues with the CH340G based modules, or more specifically the driver for them. I've recently been in touch with one of the engineers that works for WCH writing the drivers because I'd never managed to use a CH340 beyond 230400 baud on my mac. It turned out there was a bug in the driver which, to their credit, they fixed. It's now running up to 921600 baud and reliably flashing my ESPs.

I have a feeling that one of the issues at higher speed is making sure all of the relevant pins are pulled high or low, because otherwise you seem to get a lot of failures. On the board I've made it now reliably flashes every time at 921600.

I'll have to try out timing it at the different rates to see what difference it makes though.

- Wed Mar 23, 2016 4:39 am #43859 i can flash at 2Mb with CH340G (NodeMCU 0.9 board, Linux OS, stock driver) with my code.
at higher rates flashing becomes unreliable.
PL2303 takes the trophy with 4Mb - able to set and sustain. i think that 4Mb is the highest exact rate that can be achieved (divider 13), next is 8Mb (divider 4), but at lower values the data output becomes more of a sine wave than square, i don't think it'll work (but i don't have any adapters that can do 8 to test).
however, it won't make much different, i think, as time is already dominated by erase and write latency.