sl-controls
6dfb5640db
Add src/mpu6000.c implementing a complementary filter (α=0.98) on top of the existing icm42688 SPI driver. Fixes wrong scale factors in balance.c (was ±250°/s / ±2g; hardware is configured ±2000°/s / ±16g). Fusion now lives in the IMU driver layer; balance_update() consumes IMUData directly. - mpu6000_init(): calls icm42688_init(), seeds filter state - mpu6000_read(): reads raw SPI, applies complementary filter, returns fused pitch (degrees) + pitch_rate (°/s) + accel_x/z (g) - balance.c: removes duplicated fusion code, uses IMUData.pitch - main.c: switches to mpu6000_init()/mpu6000_read(), updates telemetry Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
#include "balance.h"
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#include "config.h"
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#include <math.h>
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void balance_init(balance_t *b) {
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b->state = BALANCE_DISARMED;
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b->pitch_deg = 0.0f;
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b->pitch_rate = 0.0f;
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b->integral = 0.0f;
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b->prev_error = 0.0f;
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b->motor_cmd = 0;
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/* Default PID — conservative starting point */
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b->kp = PID_KP;
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b->ki = PID_KI;
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b->kd = PID_KD;
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b->setpoint = 0.0f;
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/* Safety defaults from config */
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b->max_tilt = MAX_TILT_DEG;
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b->max_speed = MAX_SPEED_LIMIT;
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}
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void balance_update(balance_t *b, const IMUData *imu, float dt) {
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if (dt <= 0.0f || dt > 0.1f) return; /* Sanity check dt */
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/* Consume fused angle from mpu6000 complementary filter */
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b->pitch_deg = imu->pitch;
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b->pitch_rate = imu->pitch_rate;
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/* Safety: tilt cutoff */
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if (b->state == BALANCE_ARMED) {
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if (fabsf(b->pitch_deg) > b->max_tilt) {
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b->state = BALANCE_TILT_FAULT;
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b->motor_cmd = 0;
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b->integral = 0.0f;
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return;
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}
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}
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if (b->state != BALANCE_ARMED) {
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b->motor_cmd = 0;
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b->integral = 0.0f;
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b->prev_error = 0.0f;
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return;
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}
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/* PID */
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float error = b->setpoint - b->pitch_deg;
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/* Proportional */
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float p_term = b->kp * error;
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/* Integral with anti-windup */
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b->integral += error * dt;
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if (b->integral > PID_INTEGRAL_MAX) b->integral = PID_INTEGRAL_MAX;
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if (b->integral < -PID_INTEGRAL_MAX) b->integral = -PID_INTEGRAL_MAX;
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float i_term = b->ki * b->integral;
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/* Derivative on measurement (avoids setpoint kick) */
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float d_term = b->kd * (-b->pitch_rate);
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/* Sum and clamp */
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float output = p_term + i_term + d_term;
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if (output > (float)b->max_speed) output = (float)b->max_speed;
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if (output < -(float)b->max_speed) output = -(float)b->max_speed;
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b->motor_cmd = (int16_t)output;
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b->prev_error = error;
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}
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void balance_arm(balance_t *b) {
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if (b->state == BALANCE_DISARMED) {
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/* Only arm if roughly upright */
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if (fabsf(b->pitch_deg) < 10.0f) {
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b->integral = 0.0f;
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b->prev_error = 0.0f;
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b->motor_cmd = 0;
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b->state = BALANCE_ARMED;
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}
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}
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}
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void balance_disarm(balance_t *b) {
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b->state = BALANCE_DISARMED;
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b->motor_cmd = 0;
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b->integral = 0.0f;
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}
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