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Topic: What ESP32 UART Auto Program Circuit Alternatives are there? (Read 1 time) previous topic - next topic

emre_mutlu

Hi Guys,


(IMPORTANT: you can find the pictures of the circuits I am talking about in the following link also:
https://electronics.stackexchange.com/questions/528832/what-esp32-uart-auto-program-circuit-alternatives-are-there)


I am currently designing a board centered around the esp32. I want to implement an auto program circuit for conviniences sake. Because I dont want to hold a boot button eacht time I want to program it. My question is why is the below circuit that most ESPs use, designed the way it is. Because this circuit fails to initiate the upload more often than I would like and I end up having to press the boot button. So I somehow think there is something with the design that causes this, as I had this problem with more than 1 ESP at different times. Picture here "Unbennant4".



Why not use something like this for instance? This is a thought experiment I made using the logic table and KV diagrames.


(1)EN = not(DTR) + RTS


(2)IO0 = not(RTS) + DTR


From this I have developed a circuit: (Unbennant 6)

So I know this can propably be done better but maybe this will solve the reliability problem that I have. Or maybe I should use the relation I found on (1) and (2) to build the same circuit using OR-Gates. In any case any thoughts on Optimization or help on the matter would be appriciated.





Best Regards,


Emre







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