Modbus RTU Master Monitor

Summary

Firmware for a Modbus RTU master gateway on ESP32 TTGO LORA 32 V2.1 based on RS485, schedules periodic readings, normalizes data and transmits it via LoRaWAN (LMIC) within a FreeRTOS environment.

Dependencies

• FreeRTOS: tasks, queues, semaphores and synchronization.
• Arduino core ESP32 + SPI/UART + ModbusClientRTU.
• LMIC (LoRaWAN) and associated HAL stack.
• PlatformIO as recommended toolchain.

Groups

• Modbus Core: Pure Modbus (discovery, scheduler, EventManager, callbacks, tokens).
• Data Format & Payload: parsing and response normalization.
• LoRaWAN: LMIC and transmission.

General flow

1. Startup: setup() initializes Serial/SPI, ModbusClientRTU, queues and tasks.
2. Discovery: initialDiscoveryTask issues FC03→EventManager orders, which delegates to MB; parseAndStoreDiscoveryResponse fills slaveList.
3. Scheduling: initScheduler derives scheduleList; DataRequestScheduler publishes sampling events to queueEventos_Scheduler.
4. Event management: EventManager prioritizes scheduler vs peripheral, creates tokens, invokes MB.addRequest and registers context in requestBuffer.
5. Modbus callbacks: handleData/handleError encapsulate responses and send them to queueRespuestas, updating failures and cleaning scheduler as needed.
6. Formatting: DataFormatter decides if response is discovery or sampling; uses BitPacker and formatAndEnqueueSensorData to generate SensorDataPayload and sends them to queueSensorDataPayload.
7. Aggregation: DataAggregatorTask consumes payloads, builds an Activate Byte and constructs the final message with construirPayloadUnificado, which deposits to queueFragmentos.
8. LoRaWAN transmission: tareaLoRa takes fragments, waits for semaforoEnvioCompleto and calls LMIC_setTxData2; tareaRunLoop maintains os_runloop_once.

Queues and synchronization

• queueEventos_Peripheral and queueEventos_Scheduler: input to EventManager.
• queueRespuestas: bridge callbacks → formatter.
• queueSensorDataPayload: normalized data ready for aggregation.
• queueFragmentos: packets ready for LMIC.
• schedulerMutex and semaforoEnvioCompleto: critical synchronization.