u/SandHK

Looking for suggestions/guides, how tos, on using the ESP32 OTA function to program other MCUs, ideally the Pico2040 using Arduino IDE.
I have no problem using OTA on a ESP32 to update itself but not sure how to program a separate MCU.

Edit:
Apologies, my question was not very clear. I would like to use the ESP32 to program the Pico2024. I would like to upload the new Pico2020 firmware using a webapp served by the ESP32.
I had hoped I could use the ESP32 OTA function (or part of it) to upload the firmware but it seems not possible. Now looking at uploading the Pico2040 firmware (blob) to the ESP32 via normal HTML/js and then have the ESP32 program the 2040 using the uploaded file. At this time I not not worried about file size just the methods to get this working.

What additions/changes should I make to use a 2K 3900pp PTC rather than the required 2K 3500ppm PTC used in the schematic?

I have looked at the following and don't understand enough to be able to work it out myself:
Combining LT73 2k 3900ppm & 2k 3000ppm for Yusynth VCO - MOD WIGGLER
electro-music.com :: View topic - Tempco Resistor Question
https://www.elby-designs.com/webtek/datasheets/tempco.pdf

Alternatively, can the resistor be changed to something else? For example a thermistor?

Circuit can be viewed in the original thread at https://electro-music.com/forum/viewtopic.php?t=54623

Is there a browser that works well on older, lower powered devices?