Shadowtrance
dbf850c434
- M5 Unit Modules library + M5 Unit Test app - Minor fixes for TodoList, TwoEleven, Snake, Brainfuck and Breakout - Fixed SerialConsole to use the uart controller as it was broken in one of the many updates - Fixed keyboard input in TwoEleven, Breakout, Magic8Ball and Snake - Bluetooth Media Keys app, supports pressing physical keys to trigger the corresponding buttonmatrix button - Epub Reader app
57 lines
2.5 KiB
C
57 lines
2.5 KiB
C
/*
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* UnitCommon.h - shared I2C helpers for M5Stack STM32-based units
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*
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* All M5Stack Grove units with STM32 firmware require a STOP condition between
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* the register-pointer write and the data read (the STM32 HAL receive callback
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* populates tx_buffer after STOP, before the next START). Using a repeated-START
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* (the default i2c_controller_read_register) causes bus errors on every read.
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*
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* Pattern: write(reg) → STOP → vTaskDelay(2ms) → read(data)
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*/
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#pragma once
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#include <tactility/device.h>
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#include <tactility/drivers/i2c_controller.h>
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#include <freertos/FreeRTOS.h>
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#include <freertos/task.h>
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#include <cstring>
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static constexpr uint32_t UNIT_I2C_TIMEOUT_MS = 20;
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static constexpr uint32_t UNIT_I2C_PROBE_TIMEOUT_MS = 10; // shorter timeout for presence checks
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static constexpr uint32_t UNIT_STM32_READ_DELAY_MS = 2; // STM32 needs STOP + delay before read
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static constexpr uint16_t UNIT_MAX_WRITE_PAYLOAD = 32; // max bytes in a single I2C write
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// Probe whether a device exists at the given address on the given I2C bus.
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inline bool unitProbe(Device* dev, uint8_t addr) {
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return i2c_controller_has_device_at_address(
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dev, addr, pdMS_TO_TICKS(UNIT_I2C_PROBE_TIMEOUT_MS)) == ERROR_NONE;
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}
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// Write [reg, buf...] as a single transaction (STOP at end).
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inline bool unitWriteReg(Device* dev, uint8_t addr, uint8_t reg,
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const uint8_t* buf, uint16_t len) {
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if (len > UNIT_MAX_WRITE_PAYLOAD) return false;
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if (len > 0 && buf == nullptr) return false;
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uint8_t pkt[33];
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pkt[0] = reg;
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if (len) memcpy(pkt + 1, buf, len);
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return i2c_controller_write(dev, addr, pkt, (uint16_t)(len + 1),
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pdMS_TO_TICKS(UNIT_I2C_TIMEOUT_MS)) == ERROR_NONE;
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}
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// Write register pointer only (no data payload) - convenience wrapper.
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inline bool unitWriteRegPtr(Device* dev, uint8_t addr, uint8_t reg) {
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return i2c_controller_write(dev, addr, ®, 1,
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pdMS_TO_TICKS(UNIT_I2C_TIMEOUT_MS)) == ERROR_NONE;
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}
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// Read from a register: write pointer → STOP → 2ms delay → read.
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inline bool unitReadReg(Device* dev, uint8_t addr, uint8_t reg,
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uint8_t* buf, uint16_t len) {
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if (len > 0 && buf == nullptr) return false;
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if (!unitWriteRegPtr(dev, addr, reg)) return false;
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vTaskDelay(pdMS_TO_TICKS(UNIT_STM32_READ_DELAY_MS));
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return i2c_controller_read(dev, addr, buf, len,
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pdMS_TO_TICKS(UNIT_I2C_TIMEOUT_MS)) == ERROR_NONE;
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}
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