The efuse blues

[krismc]

After a long & confusing few hours with gemini we managed to blow an efuse on an esp32 ,
BLOCK3 (BLOCK3) Variable Block 3
= 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
but am unable to read it on chip in upython. Is this definitive or might there be a work around?

[bixb922]

Fuses are most easily burnt with espefuse, see https://docs.espressif.com/projects/esptool/en/latest/esp32/espefuse/index.html

AFAIK there is no MicroPython driver to read efuses. You would have to read memory registers yourself, for example using machine.mem32(). The description of registers is in https://documentation.espressif.com/esp32_technical_reference_manual_en.pdf chapter 5. It seems to be enough to read memory address EFUSE_BLKn_RDATAm_REG. The base address is shown in table Table 3.3-6. The offset is in section 5.4 registers summary.

Here is an example reading a ADC related efuse: https://github.com/matthias-bs/MicroPython-ADC_Cal