The ESP32-S3 4.2 inch E-ink display.
| Test | Item | Description |
|---|---|---|
| T0 | System Startup | Serial init, EPD init, welcome screen |
| T1 | EPD Display | White / Black / Red fill + text demo |
| T2 | WS2812 RGB LED | RED > GREEN > BLUE > WHITE cycle |
| T3 | Buttons | AP key and BOOT key press detection |
| T4 | ES8311 CODEC | I2C probe (0x18) + I2S 1 kHz tone |
| T5 | DMIC Mic | LMD4737 voice recording + RMS check |
| T6 | AHT20 Sensor | Temperature & humidity via I2C |
| T7 | Battery ADC | ADC voltage reading (skip if not fitted) |
| T8 | WiFi Scan | 2.4 GHz AP scan, expect ≥1 network |
| T9 | SD Card R/W | FSPI mount, write & read verify |
| T10 | LoRa SPI Bus | Reset chip, check BUSY low |
| T11 | Summary | Overall PASS / FAIL report |