ESP32 Forum

Not really a ESP32 project but this helps to realize an ESP32 project.
This is why i want to share it with you.

I found a lot of JTAG debuggers that could be used with the ESP32. But most of them are out of stock or discontinued. Others too expensive. So i decided to make my own JTAG debugger. It is based on the FTDI FT2232H so it is USB Hi-Speed 488Mbis/s and Full Speed 12MBit/s compatible.

Important for me are the following features:
JTAG Interface: TDI, TDO, TMS, TCK, TRST, RST (ARM compatible connector because I'm also using STM32 µControllers)
UART Interface: TxD, RxD, RTS, CTS
Accepted JTAG voltage level range: 2.3 ... 3.6V (works 1.7 ... 5V)
Accepted UART voltage level range: same as JTAG interface.

Schematics:
http://www.rf-link.de/FTDI-H_JTAG.pdf




Most other Debuggers contain no UART interface or a standard RS-232 with +/- 15V levels which is useless for ESP32 applications
because the ESP32 has the same UART output levels as ist supply voltage. This is in the range of 2.2V...3.6V. That's what my debugger supports.

So it is possible to use the UART as printf UART for debug messages or listening to UART devices that are attached to the ESP32 like a GPS module.

I built 10 units, as i only need two I'll give away the other eight. If one is interested to have one please contact me.

Hello,
Looks very interesting.

Do you know about the ESP-Prog??
https://github.com/espressif/esp-iot-so ... uide_en.md

What are the main differences? Or is your programmer the same?

Hi!

To be honest the project you mentioned was unknown to me. In principal they are similar. Mine is using real level shifters. That means it works reliable over the full ESP32 supply voltage range. The other one is only 3.3V.

Mine is available, the other one is only a reference design.


Regards,

STBESP32

Thanks for your answer!
I would be interested in getting one of the spare ones you have, how much?

If I understood correctly, it supports USB/Serial programming + communication, and also JTAG debugging right? And both things can be connected at the same time?

At the link I posted earlier, please look at sections 3.2.3 and 3.2.4, do you have anything similar to those circuits?

Thank you!

Edit: is it necessary to upload any custom firmware to the FTDI? In order to make it work as JTAG?

Hi !

If I understood correctly, it supports USB/Serial programming + communication, and also JTAG debugging right? And both things can be connected at the same time?

Yes, correct. You can use the serial connaection also not only for viewing printf outputs. You can use it also for sniffung e.g. a GPS module.

At the link I posted earlier, please look at sections 3.2.3 and 3.2.4, do you have anything similar to those circuits?

That is not included.

Edit: is it necessary to upload any custom firmware to the FTDI? In order to make it work as JTAG?

No it is not.

I would be interested in getting one of the spare ones you have, how much?

35EUR plus shipping. Where do you come from?

Regards,

STBESP32

STBESP32 wrote:I found a lot of JTAG debuggers that could be used with the ESP32. But most of them are out of stock or discontinued. Others too expensive.

Cool project!

I'm curious though - what do you consider "too expensive"? I have a C232HM that works well with the ESP32, and they are US$26 (ex. shipping) each:

https://www.mouser.com/ProductDetail/FT ... hrMA%3D%3D

It is based on the FT232H device. I've used it for JTAG debugging and JTAG flash programming. You can't use the UART at the same time, but I have the USB serial console for that.

I'm curious though - what do you consider "too expensive"? I have a C232HM that works well with the ESP32, and they are US$26 (ex. shipping) each

This cable has no level shifting but you are right in principle it works but not as reliable as a debug adapter with level shifting to the used ESP32 supply voltage. As I'm often work with low power/low voltage applications it was not the best fit for me.

it would be sweet if you could support an ESP running at 1.8v, and I could use full JTAG and Console

The debugger is able to do that. The ESP32 not.

I assume that these are all gone by now ?