Download is taking too long

I’m using 2 x ESP-32 on a win-10 machine.

My program is becoming fairly large.

What can I do to download my code faster?


Depends. Do you also take “compiling” into the downloading time or just uploading to the microcontroller?

In the first case you would need more CPU cores, the second one is dependent on the upload method. If you’re using a serial method of uploading (over a COM port), you can control the speed by setting upload_speed in the platformio.ini with the to be used baudate. 921600 is a fairly high baud rate, but you may be able to go beyond that if the ESP32 and the USB-serial converter chip of the board allows.

A different approach would be to upload via a JTAG adapter (e.g. esp-prog). JTAG download speeds can go 20MHz and beyond compared to the ~1MHz (/MBit) of serial uploads. JTAG speeds can be set in the openocd-esp32 configuration files.

In PIO I compile and then download. I can see that the download (via % complete) is longer than I like.

You suggested 2 approaches.

  1. PIO.ini file, I will try this

  2. I also have JTAG. adapter (esp-prog) any suggestions on where I would go to set this up? Possibly something that you have used and think it’s good presentation for setup.


All upload settings are to be declared in the platformio.ini. The documentation and this good online article has hands-on information.

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