ESP32 Forum

Does ESP have any documentation or tools for using the JTAG interface for factory flashing of the module. Specifically the ESP32s3 WROOM module. I am looking into this as a way to speed up programming time at the factory. Since JTAG is a clocked protocol theoretically it should be able to reach faster transfer times for code transfer. However I see no documentation that esptool supports flashing over JTAG.

Thanks,
Shawn

esptool does not support that, it's usually OpenOCD that's used for JTAG. Note that JTAG isn't usable out of the box like that, though: normally, JTAG is routed to the built-in USB-serial-JTAG converter, and you'd need to blow a fuse (via the serial port, usually) to get GPIO JTAG to work.

(In my experience, if you use either UART at a relatively high clock speed or USB, most of the bottleneck wrt writing flash actually is in the erase/write speed of the flash rather than the transport mechanism, by the way.)

We just use a ESP32-S3 with 16MB of flash, and have 8MB set apart for NVS storage that is loaded with the production firmware.
Then use a USB-C male to male cable from it to the production product to flash it. Just takes a few seconds.
We also made the programmer so that when its powered up if it detects it's plugged into a PC it acts like a portable hard drive.
So you can just simply drag your .bin files to it.

We just use a ESP32-S3 with 16MB of flash, and have 8MB set apart for NVS storage that is loaded with the production firmware.
Then use a USB-C male to male cable from it to the production product to flash it. Just takes a few seconds.
We also made the programmer so that when its powered up if it detects it's plugged into a PC it acts like a portable hard drive.
So you can just simply drag your .bin files to it.