Summary¶

Betaflight is the open-source flight controller firmware running on libdrone's Matek H7A3-SLIM. Initial setup requires flashing the correct firmware target, applying the base configuration diff via CLI, setting board orientation, calibrating battery voltage and current sensing, configuring UART port assignments, and verifying motor direction. The base configuration diff (LD_V245_Betaflight_base) covers all mandatory settings in a single paste operation. No default Betaflight profile produces a flyable libdrone — the diff must be applied before the maiden flight.

Concept¶

Firmware target and versions¶

Betaflight firmware is compiled per flight controller hardware. The correct target for the H7A3-SLIM is MATEKH743. Flashing any other target will produce a non-functional build. Betaflight 4.5 is the tested version for libdrone V2.4.5/V2.4.6. Do not use 4.4 (missing filter improvements) or pre-release builds.

Configuration diff vs full dump¶

Betaflight stores configuration as key-value pairs. A "diff" is the minimal set of settings that differ from Betaflight defaults — it can be applied cleanly on top of a fresh flash without carrying over stale settings from a previous build. A "dump" is the complete configuration including defaults — it can produce unexpected results when applied to a different firmware version.

Always start from a fresh flash, then apply the libdrone diff. Never apply a dump from a different firmware version.

UART assignment must match physical wiring¶

The diff configures specific UARTs for specific functions. The physical wiring on the H7A3-SLIM must match the UART assignments in the configuration. If a device is soldered to UART2 but the diff configures UART2 as VTX and UART1 as GPS, nothing will work correctly. Verify physical connections before applying the diff, or apply the diff first and then wire to match.

Reference¶

Betaflight base configuration diff (LD-FW-001)¶

Apply in Betaflight Configurator → CLI tab. Paste the entire block and press Enter after save.

```

MIXER / MOTORS¶

mixer QUADX set motor_poles = 14 set motor_pwm_protocol = DSHOT600 set dshot_bidir = ON set motor_direction_inversion = ON

RECEIVER¶

set receiver_type = SERIAL set serialrx_provider = CRSF

FEATURES¶

feature GPS feature TELEMETRY feature OSD feature AIRMODE feature BLACKBOX

FAILSAFE / GPS RESCUE¶

set failsafe_procedure = GPS-RESCUE set gps_rescue_angle = 32 set gps_rescue_min_sats = 8 set gps_rescue_throttle_min = 1150 set gps_rescue_throttle_max = 1700 set gps_rescue_throttle_hover = 1400 set gps_rescue_sanity_checks = RESCUE_SANITY_ON

BATTERY (SUMMER DEFAULT)¶

set vbat_min_cell_voltage = 35 set vbat_warning_cell_voltage = 36 set vbat_max_cell_voltage = 43 set current_meter = ESC set battery_capacity = 1800

PIDs — V2.4.5 starting values (Profile 1)¶

profile 1 set p_roll = 47 set i_roll = 85 set d_roll = 32 set f_roll = 105 set p_pitch = 50 set i_pitch = 85 set d_pitch = 36 set f_pitch = 105 set p_yaw = 42 set i_yaw = 85 set d_yaw = 0 set f_yaw = 100 set iterm_relax_cutoff = 15 set iterm_relax = RPY set iterm_rotation = ON set anti_gravity_gain = 5

FILTERS¶

set gyro_lowpass_hz = 200 set gyro_lowpass2_hz = 0 set dterm_lowpass_hz = 100 set dterm_lowpass2_hz = 0 set dyn_notch_count = 3 set dyn_notch_min_hz = 100 set dyn_notch_max_hz = 600 set dyn_notch_q = 250

BLACKBOX¶

set blackbox_device = ONBOARD_FLASH set blackbox_rate_num = 1 set blackbox_rate_denom = 2 set blackbox_record_acc = ON

save ```

UART port assignments¶

Configure in Betaflight Configurator → Ports tab:

Board orientation¶

If the FC is mounted with the arrow pointing forward: no adjustment needed. If mounted rotated (common to avoid connector conflicts), set in Configuration tab → Board and Sensor Alignment → Yaw Degrees = actual rotation.

Procedure¶

Initial setup sequence¶

1. Flash MATEKH743 target with Betaflight 4.5 via Configurator.
2. Connect to Configurator. Go to CLI tab.
3. Type defaults nosave to reset to factory defaults without rebooting.
4. Paste the entire diff block above. Press Enter. Wait for save to complete.
5. Reboot (Configurator will reconnect automatically).
6. Go to Ports tab. Set UART assignments per the table above.
7. Go to Configuration tab → Battery Voltage → calibrate scale factor to match handheld multimeter reading within 0.2V.
8. Go to Motors tab → verify all four motors report eRPM when spun up (props removed, battery connected).
9. Verify motor directions in Motors tab — all must match expected rotation.
10. Go to Setup tab → rotate drone on all axes → verify 3D model responds correctly.

Rationale¶

Why the diff starts with profile 1¶

Betaflight supports multiple PID profiles. The diff explicitly sets Profile 1 as the base (chase) configuration. Profile 2 is left for the low-speed compliance overlay. Applying the diff without specifying profile 1 first would write the PID values to whichever profile was last active — a non-deterministic and error-prone outcome.

Connections¶

requires: - flight-controller-hardware - dshot-protocol - rpm-filter related: - betaflight-profiles - betaflight-gps-rescue - pid-derivative-term - pro-variant leads_to: - betaflight-profiles - betaflight-gps-rescue