Micropython with Heltec LoRa (V3)

#1

I install Micropython ESP32C3.
Reboot show invalid header: 0xffffffff

Can anyone point me to the right bin for heltec V.3?

#2

Hi, I’m totally new with this board and, besides I like the features it has, I’m facing the same issue.
I’ve tried several Firmware from the micropython repo for the ESP32-S3 version (https://micropython.org/download/ESP32_GENERIC_S3/), where it states: This firmware supports configurations with and without SPIRAM (also known as PSRAM) and will auto-detect a connected SPIRAM chip at startup and allocate the MicroPython heap accordingly. However if your board has Octal SPIRAM, then use the “spiram-oct” variant.

I’ve just spent a couple of evenings trying to build a binary file without the PSAM, and still no result.
This is the printout at Shell, if I reset the board:

MPY: soft reboot
MicroPython v1.25.0-preview.393.gf1018ee5c on 2025-03-24; Generic ESP32S3 module with ESP32S3

Type "help()" for more information.

>>> ESP-ROM:esp32s3-20210327
Build:Mar 27 2021
rst:0x1 (POWERON),boot:0x28 (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:1
load:0x3fce3820,len:0x105c
load:0x403c9700,len:0x4
load:0x403c9704,len:0xbd8
load:0x403cc700,len:0x2e38
entry 0x403c989c
E (291) quad_psram: PSRAM ID read error: 0x00ffffff, PSRAM chip not found or not supported, or wrong PSRAM line mode
E (291) esp_psram: PSRAM enabled but initialization failed. Bailing out.
MicroPython v1.25.0-preview.393.gf1018ee5c on 2025-03-24; Generic ESP32S3 module with ESP32S3
Type "help()" for more information.
>>>

Do you, or anybody else, has a solution for this ?

#3

Perhaps too obvious a question, but if you ignore the PSRAM error messages, does the rest of it work?

There aren’t too many MicroPython users around these parts so you may want to ask on the MP forums.

#4

Hi Nick, thanks for your response—good question!

Both of my Heltec WiFi LoRa 32 V3 boards work fine when connected via USB to the PC, but they randomly freeze when running on a 3.7V LiPo battery, anywhere between 10 minutes to 10 hours. This is why I’m looking for a better-matched BIN file.

With a WDT enabled, the system reboots after freezing and runs again for another unpredictable period. My test code logs battery voltage and other data, but I haven’t found a clear cause yet. I’m still running tests to identify patterns.

Any suggestions are welcome!

#5

More likely to be the power hardware. Is this with the same battery? Can you try another one? Does it do anything taxing on power? If so, can you run an empty program that just counts to the serial port once a second as that’s not much load - whereas some WiFi radio bursts can be up to +300mA