SENTRx is a library for receiving and decoding data using the SENT (Single Edge Nibble Transmission) protocol. It is implemented in C and designed to work with STM32 microcontrollers using the HAL library for timer input capture.
- Supports decoding SENT fast and slow channel messages.
- Implements input capture via STM32 HAL timers.
- Provides callback mechanisms for received messages.
- Supports both standard and enhanced slow channel messages.
- Includes automatic synchronization and error checking via CRC validation.
sent_rx.h- Header file containing the SENTRx API, data structures, and macros.sent_rx.c- Implementation of the SENTRx receiver functions.
A handle structure containing:
- Base SENT handle (
SENTHandle_t) - User data pointer
- Capture timing data
- Receiver state machine
- Message buffers for fast and slow channels
- Callback functions for received messages
- Buffers for slow channel bit collection
SENTRxCallback_t- Called when a fast channel message is received.SENTRxSlowCallback_t- Called when a slow channel message is received.
uint8_t SENTRx_init(SENTRxHandle_t *const handle, SENTHandleInit_t *const init, SENTRxCallback_t rx_callback, SENTRxSlowCallback_t slow_rx_callback, void *user_data);
Initializes the SENT receiver with the given timer and callbacks.
Starts the SENT receiver by enabling timer input capture.
Handles incoming pulse capture events, processes nibbles, and triggers the state machine.
- The receiver synchronizes based on a predefined pulse width corresponding to the SENT sync frame.
- Nibbles are collected and converted into a full message.
- CRC validation is performed before invoking the callback.
- Uses a state machine to collect slow channel data bits.
- Supports both short and enhanced slow messages.
void SENT_MessageCallback(SENTMsg_t *const msg, void *user_data) {
// Process fast channel message
}
void SENT_SlowMessageCallback(SENTSlowMsg_t *const msg, void *user_data) {
// Process slow channel message
}
SENTRxHandle_t sent_rx;
SENTHandleInit_t init = { .htim = &htim1, .channel = TIM_CHANNEL_1 };
if (SENTRx_init(&sent_rx, &init, SENT_MessageCallback, SENT_SlowMessageCallback, NULL)) {
SENTRx_start(&sent_rx);
}- STM32 HAL library (for timer handling)
sent.h(base SENT protocol definitions and utilities)
This project is released under the MIT License.