ESP32

The ESP32 is the most fully-featured CONDUYT target. It supports every transport (Serial, BLE, MQTT, TCP, WebSocket) and has WiFi for networked projects.

Specs

Firmware setup

PlatformIO

; platformio.ini
[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
lib_deps = conduyt

pio run --target upload

Arduino IDE

1. Go to File → Preferences
2. In Additional Board Manager URLs, add:

   https://espressif.github.io/arduino-esp32/package_esp32_index.json
   

3. Go to Tools → Board → Boards Manager, search for esp32, and install the ESP32 package by Espressif
4. Select ESP32 Dev Module from Tools → Board → ESP32 Arduino
5. Select your port from Tools → Port
6. Click Upload

Transports

The ESP32 supports all CONDUYT transports. Pick the one that fits your project:

// USB Serial (simplest - just plug in)
ConduytSerial transport(Serial, 115200);

// Bluetooth Low Energy (wireless, no network needed)
#define CONDUYT_TRANSPORT_BLE
ConduytBLE transport("MyDevice");

// MQTT over WiFi (networked, needs a broker)
#define CONDUYT_TRANSPORT_MQTT
#include <WiFi.h>
#include <PubSubClient.h>
WiFiClient wifi;
PubSubClient mqtt(wifi);
ConduytMQTT transport(mqtt, "device-001");

// TCP over WiFi (direct network connection, no broker)
#include <WiFi.h>
WiFiServer server(3333);
ConduytTCP transport(server);

See the transport-specific guides for full setup:

• Connect over Serial
• Connect over BLE
• Connect over MQTT

Built-in LED

Pin 2 on most ESP32 dev boards (DevKitC, NodeMCU-32S, DOIT). Some boards differ:

• ESP32-S3 - uses an addressable RGB NeoPixel instead of a simple LED
• ESP32-C3 - pin 8 on some boards

If in doubt, check your board's pinout diagram.

Browser flashing

Go to the Playground, click Flash, select ESP32, and click Install CONDUYT Firmware. The web flasher auto-detects your chip variant and handles bootloader, partitions, and firmware.

Some boards require holding the BOOT button during flashing. If the flash fails, hold BOOT, click Flash again, and release BOOT after flashing starts.

OTA updates

Enable over-the-air firmware updates by adding the build flag:

build_flags = -DCONDUYT_OTA

The host can then push new firmware using OTA_BEGIN, OTA_CHUNK, and OTA_FINALIZE commands.

Common issues

• Upload fails: Hold the BOOT button while clicking Upload. Release after the upload starts. Some boards auto-reset, others don't.
• WiFi won't connect: The ESP32 only supports 2.4 GHz networks. 5 GHz SSIDs are invisible to it. Also verify SSID and password are correct (case-sensitive).
• BLE disconnects when WiFi is active: BLE and WiFi share the same 2.4 GHz radio. Running both simultaneously can cause instability. Pick one transport per project when possible.
• Inaccurate analog readings: The ESP32's 12-bit ADC has known nonlinearity issues. For precision measurements, use an external ADC (ADS1115, MCP3008).
• GPIO 6-11: These are connected to the internal SPI flash. Do not use them as GPIO - it will crash the board.