Scematics review required on ESP- Wroom 32

senudajayalath
Posts: 17
Joined: Sun Jan 03, 2021 8:00 am

Scematics review required on ESP- Wroom 32

Postby senudajayalath » Sun Jan 03, 2021 8:50 am

This is the schematics provided in the official datasheet for ESP Wroom 32. The link to the datasheet is given as https://www.espressif.com/sites/default ... eet_en.pdf
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I have some problem regarding this. Please help me with these problems.

1. I have heard that ESP32 needs to be reset (en pressed and released) and the bootload (GPIo0) pressed and released before a code is uploaded. And also I have heard that GPIO0 should be pulled to high. But neither of the above is satisfied in the above schematics. Am I missing something or is it only valid for ESP32 wrover and not for ESP32 Wroom ?

2. What is the purpose of this ? Is it a mandatory requirement ?
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3. What is the best way to upload code into a ESP32. Will this work ? Is it the best choise
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Can I upload code using the Arduino IDE with this. If so how do I do it?

Thanks for the help!!!!

ESP_Sprite
Posts: 9769
Joined: Thu Nov 26, 2015 4:08 am

Re: Scematics review required on ESP- Wroom 32

Postby ESP_Sprite » Mon Jan 04, 2021 1:36 am

The schematic does have a reset circuit. Look at C3/R1. (The values in the schematic are TBD, but I think the text in the datasheet gives the proper ones.)

JTAG is optional; it can be useful if you want to debug your program using a debugger (in contrast to e.g. putting printf lines in your code).

That USB-to-serial converter will probably work, just make sure you have jumpers or buttons for reset and 'boot option' things in the schematics as you'll need them to put the board into bootloader mode. Alternatively, get an USB-to-serial board that brings out DTR and RTS and build up the two-transistor reset/io0 schematic as seen in e.g. the ESP32-DevkitC schematic (around Q1/D2 there).

senudajayalath
Posts: 17
Joined: Sun Jan 03, 2021 8:00 am

Re: Scematics review required on ESP- Wroom 32

Postby senudajayalath » Mon Jan 04, 2021 8:28 am

ESP_Sprite wrote:
Mon Jan 04, 2021 1:36 am

Alternatively, get an USB-to-serial board that brings out DTR and RTS and build up the two-transistor reset/io0 schematic as seen in e.g. the ESP32-DevkitC schematic (around Q1/D2 there).
I didnt understand this part . Could you please explain. Sorry for any trouble. And also when uploading code from Arduino IDE through USB to serial TTL converter do you need to do anything extra (Like pressing bootload button before or while uploading)

ESP_Sprite
Posts: 9769
Joined: Thu Nov 26, 2015 4:08 am

Re: Scematics review required on ESP- Wroom 32

Postby ESP_Sprite » Tue Jan 05, 2021 1:20 am

You can either have a boot and reset button, in which case you need to press those before uploading, or you can have the little transistor circuit I showed, in which case you need an USB-to-serial converter that brings out RTS/DTR but you don't need to press any button when uploading code.

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