ESP32 eFuse Chip Revision Read Error

In this tutorial, you'll learn about ESP32 eFuse Chip Revision Read Error. We cover key concepts, practical examples, and best practices.

The Problem

ESP32 chip revision read via eFuse returns incorrect version or fails.

Quick Fix

Wrong

Serial.printf("Chip rev: %d\n", ESP.getChipRevision());  // May be wrong

Chip revision: 0 (but chip is actually revision 3)

Right

uint32_t rev = 0;
esp_efuse_read_field_blob(ESP_EFUSE_CHIP_VER_REV1, &rev, 8);
uint32_t rev2 = 0;
esp_efuse_read_field_blob(ESP_EFUSE_CHIP_VER_REV2, &rev2, 3);
uint32_t fullRev = (rev2 << 8) | rev;
Serial.printf("Chip revision: %d (0x%03X)\n", fullRev, fullRev);

Chip revision: 3 (0x003)
(Matches printed label on chip package)

Prevention

Use ESP-IDF functions for revision, not Arduino ESP.getChipRevision(). Chip revision affects errata workarounds. Revision 3 fixes ADC2 and touch sensor issues. Revision 1 has Bluetooth issues fixed in rev 2.

DodaTech engineers apply these same patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro for production IoT reliability.

FAQ