Shadowtrance
71 lines
3.0 KiB
C
71 lines
3.0 KiB
C
/*
|
|
* UnitCommon.h - shared I2C helpers for M5Stack STM32-based units
|
|
*
|
|
* All M5Stack Grove units with STM32 firmware require a STOP condition between
|
|
* the register-pointer write and the data read (the STM32 HAL receive callback
|
|
* populates tx_buffer after STOP, before the next START). Using a repeated-START
|
|
* (the default i2c_controller_read_register) causes bus errors on every read.
|
|
*
|
|
* Pattern: write(reg) → STOP → vTaskDelay(2ms) → read(data)
|
|
*/
|
|
#pragma once
|
|
|
|
#include <tactility/device.h>
|
|
#include <tactility/drivers/i2c_controller.h>
|
|
#include <freertos/FreeRTOS.h>
|
|
#include <freertos/task.h>
|
|
#include <cstring>
|
|
|
|
static constexpr uint32_t UNIT_I2C_TIMEOUT_MS = 20;
|
|
static constexpr uint32_t UNIT_I2C_PROBE_TIMEOUT_MS = 10; // shorter timeout for presence checks
|
|
static constexpr uint32_t UNIT_STM32_READ_DELAY_MS = 2; // STM32 needs STOP + delay before read
|
|
static constexpr uint16_t UNIT_MAX_WRITE_PAYLOAD = 32; // max bytes in a single I2C write
|
|
|
|
// I2C addresses of the unit modules this library can drive (excludes PaHub itself
|
|
// and UART-only units like MIDI). Used by PaHub channel probing instead of a full
|
|
// 0x08-0x77 bus scan: the ESP-IDF i2c_master driver's probe op can wedge the bus
|
|
// FSM after heavy NACK traffic, so scanning only known addresses avoids that.
|
|
static constexpr uint8_t KNOWN_UNIT_ADDRS[] = {
|
|
0x28, // UnitRfid2
|
|
0x3E, // UnitLcd
|
|
0x40, // UnitScroll
|
|
0x41, // Unit8Encoder
|
|
0x47, // UnitByteButton
|
|
0x5F, // UnitCardKB2
|
|
0x63, // UnitJoystick2
|
|
};
|
|
|
|
// Probe whether a device exists at the given address on the given I2C bus.
|
|
inline bool unitProbe(Device* dev, uint8_t addr) {
|
|
return i2c_controller_has_device_at_address(
|
|
dev, addr, pdMS_TO_TICKS(UNIT_I2C_PROBE_TIMEOUT_MS)) == ERROR_NONE;
|
|
}
|
|
|
|
// Write [reg, buf...] as a single transaction (STOP at end).
|
|
inline bool unitWriteReg(Device* dev, uint8_t addr, uint8_t reg,
|
|
const uint8_t* buf, uint16_t len) {
|
|
if (len > UNIT_MAX_WRITE_PAYLOAD) return false;
|
|
if (len > 0 && buf == nullptr) return false;
|
|
uint8_t pkt[33];
|
|
pkt[0] = reg;
|
|
if (len) memcpy(pkt + 1, buf, len);
|
|
return i2c_controller_write(dev, addr, pkt, (uint16_t)(len + 1),
|
|
pdMS_TO_TICKS(UNIT_I2C_TIMEOUT_MS)) == ERROR_NONE;
|
|
}
|
|
|
|
// Write register pointer only (no data payload) - convenience wrapper.
|
|
inline bool unitWriteRegPtr(Device* dev, uint8_t addr, uint8_t reg) {
|
|
return i2c_controller_write(dev, addr, ®, 1,
|
|
pdMS_TO_TICKS(UNIT_I2C_TIMEOUT_MS)) == ERROR_NONE;
|
|
}
|
|
|
|
// Read from a register: write pointer → STOP → 2ms delay → read.
|
|
inline bool unitReadReg(Device* dev, uint8_t addr, uint8_t reg,
|
|
uint8_t* buf, uint16_t len) {
|
|
if (len > 0 && buf == nullptr) return false;
|
|
if (!unitWriteRegPtr(dev, addr, reg)) return false;
|
|
vTaskDelay(pdMS_TO_TICKS(UNIT_STM32_READ_DELAY_MS));
|
|
return i2c_controller_read(dev, addr, buf, len,
|
|
pdMS_TO_TICKS(UNIT_I2C_TIMEOUT_MS)) == ERROR_NONE;
|
|
}
|