Auto Upload Circuit?

m.rowe
Posts: 4
Joined: Fri Mar 13, 2020 3:52 pm

Auto Upload Circuit?

Postby m.rowe » Fri Mar 13, 2020 4:34 pm

I see many references on implementing an auto upload circuit for the ESP32.
Most are variants of this circuit:
ESP32_Auto_Upload.png
ESP32_Auto_Upload.png (7.78 KiB) Viewed 1817 times
Having set the back-story, my question is this: The Arduino IDE is using a USB to Serial Module (model unspecified) to send the program to the ESP32 in response to the GUI Upload command. How, when and by What are the DTR &/or RTS signals generated?

If the Arduino Upload was being handled by the "Upload by Programmer" I would go looking for an answer in the programmers.txt file.

An additional confusion to me (not very difficult!), if I look to a genuine FTDI TTL-232R device (https://www.farnell.com/datasheets/814049.pdf), the DTR control line is not shown?

Regards, Martin

pipi61
Posts: 34
Joined: Fri Dec 23, 2016 10:58 pm

Re: Auto Upload Circuit?

Postby pipi61 » Fri Mar 13, 2020 6:32 pm

Use another type usb/serial converter/adapter. Before buy check connector pinout, or chip type on adapter.
In adapter if not wire the required signal to connector, then wire directly from chip pin.
Check power/gpio voltage level on adapter, and select 3V3 type.
I use simple wiring, RX,TX, GND, RTS to EN(reset), DTR to GPIO0

m.rowe
Posts: 4
Joined: Fri Mar 13, 2020 3:52 pm

Re: Auto Upload Circuit?

Postby m.rowe » Sat Mar 14, 2020 6:09 pm

Hi,
Thank you for the response.
When you say: "I use simple wiring, RX,TX, GND, RTS to EN(reset), DTR to GPIO0"
Do you mean that RTS is connected DIRECTLY to EN? You are not using any interface or timing circuitry?
Like this?
ESP32_Auto_upload2.png
ESP32_Auto_upload2.png (2.73 KiB) Viewed 1758 times
Regards, Martin

pipi61
Posts: 34
Joined: Fri Dec 23, 2016 10:58 pm

Re: Auto Upload Circuit?

Postby pipi61 » Mon Mar 16, 2020 6:32 pm

Yes, directly. I use this ch340 adapter https://www.aliexpress.com/item/3278945 ... 4c4dl0bJvQ This adapter connector does not have a DTR signal but a wire soldered directly to the ch340 pin, The power jumper select 3,3V position on adapter. The usb 5V power signal is connected to the esp32cam module's 5V power supply

m.rowe
Posts: 4
Joined: Fri Mar 13, 2020 3:52 pm

Re: Auto Upload Circuit?

Postby m.rowe » Mon Mar 16, 2020 9:06 pm

Thank you.

All understood & working now.

Regards,

Who is online

Users browsing this forum: phoenix2000 and 20 guests