USART1 IDLE interrupt (DMA circular RX) was calling HAL_UART_IRQHandler
mid-frame during polling HAL_UART_Transmit, resetting gState and causing
leading nulls / truncated frames on the Jetson telemetry link at 921600 baud.
Fix: introduce jlink_tx_locked() which disables USART1_IRQn around every
blocking HAL_UART_Transmit call, preventing IRQHandler from corrupting
gState while the TX loop is running. A s_tx_busy flag drops any
re-entrant caller (ESC debug, future USART6/VESC paths).
Both jlink_send_telemetry (50 Hz) and jlink_send_power_telemetry (1 Hz)
now use jlink_tx_locked(). Also correct the stale config.h comment that
misidentified the Jetson link as USART6 (it moved to USART1 in Issue #120).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Implements TIM4 PWM driver for 2-servo camera mount with:
- 50 Hz PWM frequency (standard servo control)
- CH1 (PB6) pan servo, CH2 (PB7) tilt servo
- 0-180° angle range → 500-2500 µs pulse width mapping
- Non-blocking servo_set_angle() for immediate positioning
- servo_sweep() for smooth pan-tilt animation (linear interpolation)
- Independent sweep control per servo (pan and tilt move simultaneously)
- 15 comprehensive unit tests covering all scenarios
Integration:
- servo_init() called at startup after power_mgmt_init()
- servo_tick(now_ms) called every 1ms in main loop
- Ready for camera/gimbal control automation
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Adds STM32F7 STOP-mode power management with <10ms wake latency:
- power_mgmt.c: state machine (ACTIVE→SLEEP_PENDING→SLEEPING→WAKING),
30s idle timeout (PM_IDLE_TIMEOUT_MS), 3s LED fade before STOP,
gate SPI3/I2S3+SPI2+USART6+UART5 on sleep (clock-only, state preserved),
EXTI1(PA1/CRSF)+EXTI7(PB7/JLink)+EXTI4(PC4/IMU) wake sources,
PLL restore after STOP (PLLM=8/N=216/P=2 → 216MHz), uwTick save/restore
- Peripheral gating: I2S3, SPI2(OSD), USART6, UART5 disabled during STOP;
SPI1(IMU), UART4(CRSF), USART1(JLink), I2C1 remain active as wake sources
- Sleep LED: triangle-wave pulse (2s period) on LED1 during SLEEP_PENDING,
software PWM in main loop (1-bit, pm_pwm_phase vs brightness)
- IWDG: fed just before WFI; <10ms wake << 50ms WATCHDOG_TIMEOUT_MS
- JLink: JLINK_CMD_SLEEP=0x09, JLINK_TLM_POWER=0x81 (11-byte power frame
at 1Hz: power_state, est_total_ma, est_audio_ma, est_osd_ma, idle_ms)
- main.c: power_mgmt_init(), activity() on CRSF/JLink/armed, tick() when
disarmed, sleep_req handler, LED PWM, JLINK_TLM_POWER telemetry
- config.h: PM_* constants, PM_CURRENT_*_MA estimates, PM_TLM_HZ
- test_power_mgmt.py: 72 tests passing (state machine, LED, gating,
current estimates, JLink protocol, wake latency, hardware constants)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
On boot, before the main loop, sample 1000 gyro readings (~1s) while
board is held still. Compute per-axis mean offset (sensor-frame raw LSBs)
and subtract from all subsequent readings in mpu6000_read().
- mpu6000_calibrate(): LED1+LED2 solid ON during 1s sample window,
resets filter state to zero once bias is known
- mpu6000_is_calibrated(): gate; main loop blocks arming and USB
streaming until calibration completes
- Bias subtracted in sensor frame before CW270 axis transform + scale,
so all three axes (pitch/roll/yaw rate) benefit
- config.h: GYRO_CAL_SAMPLES=1000
- No flash storage — recalibrate fresh each boot (bias varies with temp)
Closes#21 (3.5°/s yaw drift), #23 (gyro bias calibration on boot).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adds motor_driver.c/h between the balance PID and the raw
hoverboard UART driver:
- Differential drive: balance_cmd → speed, steer_cmd → steer
- Steer-only ramping at MOTOR_STEER_RAMP_RATE (balance PID keeps
full immediate authority — no ramp on speed channel)
- Headroom clamp: reduces steer so |speed|+|steer|<=MOTOR_CMD_MAX
ensuring ESC never clips the balance command
- Emergency stop: latches on TILT_FAULT, clears on BALANCE_DISARMED;
send path stays in 50Hz ESC tick to avoid flooding UART
main.c: replace bare hoverboard_send() with motor_driver_update();
config.h: MOTOR_CMD_MAX=1000, MOTOR_STEER_RAMP_RATE=20 counts/ms
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
