sl-firmware
eceda99bb5
Implements complete I2C1 driver for TI INA219 power monitoring IC supporting: - Dual sensors on I2C1 (left motor @ 0x40, right motor @ 0x41) - Auto-calibration for 5A max current, 0.1Ω shunt resistance - Current LSB: 153µA, Power LSB: 3060µW (20× current LSB) - Bus voltage: 0-26V @ 4mV/LSB (13-bit, 4mV resolution) - Shunt voltage: ±327mV @ 10µV/LSB (signed 16-bit) - Calibration register computation for arbitrary max current/shunt values - Efficient single/batch read functions (voltage, current, power) - Alert threshold configuration for overcurrent protection - Full test suite: 12 passing unit tests covering calibration, conversions, edge cases Integration: - ina219_init() called after i2c1_init() in main startup sequence - Ready for motor power monitoring and thermal protection logic Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
118 lines
3.3 KiB
C
118 lines
3.3 KiB
C
#ifndef INA219_H
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#define INA219_H
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#include <stdint.h>
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#include <stdbool.h>
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/*
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* ina219.h — INA219 power monitor driver (Issue #214)
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*
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* I2C1 driver for motor current/voltage/power monitoring.
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* Supports 2 sensors (left/right motor) on I2C1 (PB8=SCL, PB9=SDA).
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*
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* INA219 specs:
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* - I2C addresses: 0x40–0x4F (configurable via address pins)
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* - Bus voltage: 0–26V, 4mV/LSB
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* - Shunt voltage: ±327mV, 10µV/LSB
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* - Current: derived from shunt voltage (calibration-dependent)
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* - Power: (Bus V × Current) / internal gain
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*
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* Typical usage for motor monitoring:
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* - 0.1Ω shunt resistor → ~3.27A max (at ±327mV)
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* - Calibration: set max expected current, driver calculates LSB
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* - Read functions return actual voltage/current/power values
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*/
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/* INA219 sensors (2 motors) */
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typedef enum {
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INA219_LEFT_MOTOR = 0, /* Address 0x40 */
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INA219_RIGHT_MOTOR = 1, /* Address 0x41 */
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INA219_COUNT
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} INA219Sensor;
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/* INA219 measurement data */
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typedef struct {
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uint16_t bus_voltage_mv; /* Bus voltage in mV (0–26000) */
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int16_t shunt_voltage_uv; /* Shunt voltage in µV (±327000) */
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int16_t current_ma; /* Current in mA (signed) */
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uint32_t power_mw; /* Power in mW */
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} INA219Data;
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/*
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* ina219_init()
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*
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* Initialize I2C1 and both INA219 sensors (left + right motor).
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* Performs auto-calibration for typical motor current monitoring.
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* Call once at startup after i2c1_init().
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*/
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void ina219_init(void);
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/*
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* ina219_calibrate(sensor, max_current_ma, shunt_ohms_milli)
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*
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* Manually calibrate a sensor for expected max current and shunt resistance.
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* Calculates internal calibration register value.
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*
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* Example:
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* ina219_calibrate(INA219_LEFT_MOTOR, 5000, 100); // 5A max, 0.1Ω shunt
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*/
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void ina219_calibrate(INA219Sensor sensor, uint16_t max_current_ma, uint16_t shunt_ohms_milli);
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/*
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* ina219_read(sensor, data)
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*
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* Read all measurements from a sensor (voltage, current, power).
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* Blocks until measurements are ready (typically <1ms at default ADC resolution).
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*
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* Returns: true if read successful, false on I2C error.
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*/
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bool ina219_read(INA219Sensor sensor, INA219Data *data);
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/*
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* ina219_read_bus_voltage_mv(sensor, voltage_mv)
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*
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* Read bus voltage only (faster than full read).
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* Returns: true if successful.
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*/
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bool ina219_read_bus_voltage_mv(INA219Sensor sensor, uint16_t *voltage_mv);
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/*
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* ina219_read_current_ma(sensor, current_ma)
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*
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* Read current only (requires prior calibration).
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* Returns: true if successful.
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*/
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bool ina219_read_current_ma(INA219Sensor sensor, int16_t *current_ma);
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/*
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* ina219_read_power_mw(sensor, power_mw)
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*
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* Read power consumption only.
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* Returns: true if successful.
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*/
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bool ina219_read_power_mw(INA219Sensor sensor, uint32_t *power_mw);
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/*
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* ina219_alert_enable(sensor, current_limit_ma)
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*
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* Enable alert pin when current exceeds limit (overcurrent protection).
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* Alert pin: GPIO, active high, open-drain output.
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*/
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void ina219_alert_enable(INA219Sensor sensor, uint16_t current_limit_ma);
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/*
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* ina219_alert_disable(sensor)
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*
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* Disable alert for a sensor.
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*/
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void ina219_alert_disable(INA219Sensor sensor);
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/*
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* ina219_reset(sensor)
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*
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* Perform soft reset on a sensor (clears all registers to default).
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*/
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void ina219_reset(INA219Sensor sensor);
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#endif /* INA219_H */
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