SendIt - ADC Input Multitool
SendIt is an open-hardware, open-firmware controller designed as a multi use tool for handling various inputs with a focus on DIY marine usage. It runs on the Yarrboard Framework and provides a clean web UI for configuration, and multiple different APIs for accessing your data.
Built on the ESP32-S3, SendIt has 8 channels of 16-bit ADC with configurable input circuits. This board can handle these types of inputs:
- 4-20ma Transducers/Senders
- 240-30 ohm / 0-180 ohm senders
- Positive Switching
- Negative Switching
- 0-32v Input
- 0-5v Input
- 0-10k ohm resistance
- Thermistors
- Raw ADC Input
User Interface

- Local HTML5 web interface served from the ESP32
- Fast, mobile-friendly design
- Works on phones, laptops, and supported MFDs
- Real-time dashboard with sensor readings
- Web based UI config - no manually editing config files
Integrations
- MQTT
- SignalK
- Home Assistant
- HTTP/REST endpoints
- WebSocket real-time control
