zacdbg
October 4, 2023, 7:20pm
1
I have a weird issue when trying the new CH340X (the X is very very important, it is unlike any other CH340 chip) Schematic:
First of all, i do not know if this is the issue with pio or drivers or upload tool so if this isn’t a place to ask please let me know.
Long story short: I have made a circuit with CH340X and esp32 however it does not work (still need to manually pull boot0 to low)
Checked with scope and timings are way off:
Obviously this isnt going to work so my question is, can i fix that somehow with config or is there any other solution?
EDIT: I swapped the EN with boot and now suddenly it started working, is it perhaps somehow swapped in software?
Per https://dl.espressif.com/dl/schematics/esp32_devkitc_v4-sch.pdf the reset circuit is
The espressiv schematics do not contain a 4.7K connection between DTR and CTS and you’re also missing any current-limiting resistors for the base or all transistors.
zacdbg
October 5, 2023, 10:23am
3
espressif doesn’t contain 4.7k because its a unique feature of X version of CH340,
And it has to be there (or to gnd to make it open source DTR) otherwise it defaults to TNOW
Also i am using UMH3N which has current limiting resistors inside package (4.7kOhm):
funny thing is when i swapped schematic to this (basically moved labels Reset and EN) it started working:
Any advise?
