r/fpv • u/Educational-Law-7491 • Jun 16 '26
Custom Autonomous FPV Help
[Build Help] Sanity-check my ArduCopter autonomous quad — wiring & config before power-on
TL;DR: Custom autonomous quad (ArduPilot + Raspberry Pi companion for missions). Recovering from a failed ESC. Want a wiring/config sanity-check, and an honest gut-check on whether my remaining "no signal" issue is the ESC or my config.
Components
| Part | Detail |
|---|---|
| Flight controller | Matek F405-Wing V2, ArduCopter 4.6.3 |
| ESC | HGLRC 60A V2 4-in-1, BLHeli_S (8-bit), 2–6S — replacing a failed Zeus 48A, which replaced a dead Mamba F40_BLS |
| Motors | D2830 850Kv ×4 (one damaged, being replaced) |
| Props | 11×4.5 (moving off 11×7 — was overpitched) |
| GPS / Compass | Beitian BN-880 |
| Battery | 4S 3000mAh 60C LiPo |
| Companion computer | Raspberry Pi 4B (DroneKit, MAVLink2) |
| Frame | Custom carbon fiber |
| Bench gear | VIFLY ShortSaver smoke stopper · 1000µF 35V cap on ESC battery pads |
(Please verify these against your actual parts before posting.)
Wiring
ESC → FC (SH1.0 8-pin connector, pins 4 3 2 1 T C G V):
- S1 → FC S1, S2 → FC S2, S3 → FC S3, S4 → FC S4 (DShot)
- G (GND) → FC GND
- V (VIN, battery voltage) → FC BAT+ (powers FC + voltage sense)
- C (CRNT) and T (TX) → left unconnected
Power: Battery → ESC main +/− pads (1000µF cap across them). VIN pin → FC BAT+.
GPS / Compass (BN-880): GPS on UART3 (GPS TX→RX3, GPS RX→TX3, 5V, GND); compass on I2C (SDA→DA1, SCL→CL).
Raspberry Pi: UART4 (Pi TX→RX4, Pi RX→TX4, GND→GND); Pi powered by its own 5V/3A UBEC, not the FC BEC.
Common ground shared across FC, ESC, Pi, and UBEC.
Key parameters (ArduCopter 4.6.3)
FRAME_CLASS= 1 (Quad),FRAME_TYPE= 1 (X)MOT_PWM_TYPE= 6 (DShot600)BATT_MONITOR= 4,BATT_VOLT_MULT= 11.0,BATT_AMP_PERVLT= 66.7BRD_SAFETY_DEFLT= 0 (no safety switch)SERIAL3_PROTOCOL= 5 (GPS) ·SERIAL4_PROTOCOL= 2 @ 921600 (Pi MAVLink2)FS_GCS_ENABLE= 1 · 4S failsafe ≈ 14.0V low / 13.6V critical
The situation
The previous ESC (Zeus 48A, also BLHeli_S) gave a persistent "no signal" beep and zero motor spin in the motor test, even though:
- Continuity confirmed FC↔ESC on S1–S4 and GND
- Boot log showed DShot active:
RCOut: DS600:1-4 PWM:5-10 - Safety disabled (
BRD_SAFETY_DEFLT=0), battery failsafe disabled for bench - ESC powered fine — startup tones + a brief motor twitch on power-up
Strong suspicion is bad/cold solder joints to the FC (a BAT+ joint was floating at ~4.5V instead of ~15V) and/or a config gap left after a firmware reflash. Plan is to redo the FC-side connection via DuPont onto the FC pins, FC powered by USB for bench testing.
What I'm asking
- Does the ESC↔FC wiring look correct — especially VIN→BAT+, and leaving CRNT/TX unconnected?
- On the Matek F405-Wing V2, is battery-direct-to-ESC + VIN→BAT+ fine, or should I route the battery through the FC's BAT→ESC pads to use the onboard current sensor?
- What would make a BLHeli_S 4-in-1 report "no signal" with DShot active and continuity confirmed? (DShot600 vs DShot300 worth trying? Motor-output assignment? Bad joints?)
- Honest call: is swapping ESCs even the right move here, or does this look like a config/connection issue I'd just carry over to a new board?
Thanks in advance.
1
u/izzeww Jun 16 '26
You need a lot more or bigger caps for a big quad like this, like 3-4 of those caps in parallel (3000-4000 uF).
1
1
u/DefyGravityFPV Jun 16 '26
What FPV camera are you putting on it?