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Firmware Starter — ESP32-S3-WROOM-1-N16R8
Platform & Toolchain
- MCU: ESP32-S3-WROOM-1-N16R8
- Framework: Arduino via PlatformIO
- USB programming: native ESP32-S3 USB Serial/JTAG on GPIO19/GPIO20
Pin Mapping
Table
| Function | ESP32 GPIO | Net | Connected To | Notes |
|---|---|---|---|---|
| USB D- | 19 | USB_DN | USB-C Dn1/Dn2 | Native USB programming/data |
| USB D+ | 20 | USB_DP | USB-C Dp1/Dp2 | Native USB programming/data |
| BOOT | 0 | ESP_BOOT | BOOT button + 10k pull-up | Hold BOOT, tap RESET to enter download mode |
| EN/RESET | EN | ESP_EN | RESET button + 10k pull-up + 1uF | Active low reset |
| IMU SPI SCK | 12 | SPI_SCK | ICM-42688-P AP_SCLK + header pin 3 | SPI clock |
| IMU SPI MOSI | 11 | SPI_MOSI | ICM-42688-P AP_SDI + header pin 4 | SPI data to sensor |
| IMU SPI MISO | 13 | SPI_MISO | ICM-42688-P AP_SDO + header pin 5 | SPI data from sensor |
| IMU CS | 10 | IMU_CS | ICM-42688-P AP_CS + 10k pull-up | Active low |
| IMU INT1 | 9 | IMU_INT1 | ICM-42688-P INT1 | Motion/data-ready interrupt |
| External CS/GPIO | 14 | EXT_CS_GPIO | Header pin 6 | Spare chip-select/GPIO for external SPI sensor |
Header pinout: 1=3V3, 2=GND, 3=SPI_SCK, 4=SPI_MOSI, 5=SPI_MISO, 6=EXT_CS_GPIO.
platformio.ini
Ini
[env:esp32-s3-devkitc-1] platform = espressif32 board = esp32-s3-devkitc-1 framework = arduino monitor_speed = 115200 upload_protocol = esptool build_flags = -DARDUINO_USB_MODE=1 -DARDUINO_USB_CDC_ON_BOOT=1 lib_deps =
Complete Firmware Source
Cpp
#include <Arduino.h> #include <WiFi.h> #include <SPI.h> #define PIN_IMU_SCK 12 #define PIN_IMU_MOSI 11 #define PIN_IMU_MISO 13 #define PIN_IMU_CS 10 #define PIN_IMU_INT1 9 #define PIN_EXT_CS_GPIO 14 #define ICM_REG_WHO_AM_I 0x75 #define ICM_REG_DEVICE_CONFIG 0x11 #define ICM_REG_PWR_MGMT0 0x4E #define ICM_SPI_READ 0x80 const char* WIFI_SSID = "YOUR_SSID"; const char* WIFI_PASSWORD = "YOUR_PASSWORD"; SPIClass imuSPI(FSPI); unsigned long lastReadMs = 0; uint8_t icmReadReg(uint8_t reg) { digitalWrite(PIN_IMU_CS, LOW); imuSPI.transfer(reg | ICM_SPI_READ); uint8_t value = imuSPI.transfer(0x00); digitalWrite(PIN_IMU_CS, HIGH); return value; } void icmWriteReg(uint8_t reg, uint8_t value) { digitalWrite(PIN_IMU_CS, LOW); imuSPI.transfer(reg & 0x7F); imuSPI.transfer(value); digitalWrite(PIN_IMU_CS, HIGH); } bool initICM42688() { pinMode(PIN_IMU_CS, OUTPUT); digitalWrite(PIN_IMU_CS, HIGH); pinMode(PIN_IMU_INT1, INPUT); pinMode(PIN_EXT_CS_GPIO, OUTPUT); digitalWrite(PIN_EXT_CS_GPIO, HIGH); imuSPI.begin(PIN_IMU_SCK, PIN_IMU_MISO, PIN_IMU_MOSI, PIN_IMU_CS); delay(10); uint8_t who = icmReadReg(ICM_REG_WHO_AM_I); Serial.printf("ICM WHO_AM_I = 0x%02X\n", who); icmWriteReg(ICM_REG_DEVICE_CONFIG, 0x01); // soft reset delay(2); icmWriteReg(ICM_REG_PWR_MGMT0, 0x0F); // accel+gyro low-noise mode delay(50); return true; } void initWiFi() { WiFi.mode(WIFI_STA); WiFi.begin(WIFI_SSID, WIFI_PASSWORD); Serial.print("Connecting WiFi"); for (int i = 0; i < 20 && WiFi.status() != WL_CONNECTED; ++i) { delay(500); Serial.print("."); } if (WiFi.status() == WL_CONNECTED) { Serial.printf("\nWiFi OK: %s\n", WiFi.localIP().toString().c_str()); } else { Serial.println("\nWiFi not connected; continuing offline."); } } void setup() { Serial.begin(115200); delay(1000); Serial.println("IRMA vibration IoT firmware starting"); initICM42688(); initWiFi(); } void loop() { if (millis() - lastReadMs >= 1000) { lastReadMs = millis(); uint8_t who = icmReadReg(ICM_REG_WHO_AM_I); Serial.printf("ICM42688 alive, WHO_AM_I=0x%02X, INT1=%d\n", who, digitalRead(PIN_IMU_INT1)); } if (WiFi.status() != WL_CONNECTED) { // Optional: reconnect or buffer vibration data locally. } }
Build & Flash
- Build:
pio run - Flash:
pio run -t upload - Monitor:
pio device monitor - Manual bootloader: hold BOOT, tap RESET, release BOOT, then upload.
Platform & Toolchain
Pin Mapping
platformio.ini
Complete Firmware Source
Build & Flash
