ESC Telemetry/RPM/Bidirectional DShot Issues: Holybro BLHeli_S/Bluejay V0.21, Pixhawk 6C, Ardupilot

ArduCopter Copter 4.5
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1

Edit: Issue was resolved by updating the firmware to bdshot specific firmware, see here.

Hi all,

I’m trying to get ESC telemetry data, specifically RPM data.

Currently seeing no ESC data for any esc’s in the “status” tab, no RPM for RPM1 in the QUICK menu, no ESC data logged in the Dataflash Log.

Wondering if there’s a setting I’ve missed, or something else to try.

Thanks for any input!

Specs:

  • Arducopter 4.5.4
  • Mission Planner 1.3.82
  • Holybro Pixhawk 6C
  • Holybro BLHeli_S flashed with Bluejay v0.21 using https://esc-configurator.com/
  • Setup>Mandatory Hardware>ESC Calibration>ESC Type set to DShot600, also tried 300.

Notes:

  1. ESC’s are plugged into the FMU/PWM Out port on the Pixhawk.
  2. BLH Pass through worked for flashing.
  3. The motors are all working on channels 9-12, as per the Configure Servo Functions section here.
  4. Setup > Optional Hardware > Motor Tests works as expected.
  5. RC Banner is correct as per the Check RC Banner section here.

Following Chris Rosser’s excellent tuning video…

Harmonic Notch Stuff:
INS_HNTCH_ENABLE = 1
INS_HNTCH_HMNCS = 7
INS_HNTCH_MODE = 3
INS_HNTCH_OPTIONS=0

RPM/ESC Stuff:
RPM1_TYPE = 5 (ESC Telemetry Motors Bitmask)
RPM1_ESC_MASK = 3840 (For channels 9-12)
SERVO_BLH_AUTO = 1 (From flashing esc’s)
SERVO_BLH_BDMASK = 3840 (For channels 9-12)
SERVO_BLH_POLES = 12 (Counted, Holybro Motors)
SERVO_DSHOT_ESC= 2 (BLHeli_S/Bluejay)

2

Notch is irrelevant and disable the RPM parameters. Or, just post the Parameter file.

1 Like
3

Thanks for the response, I set all the Notch settings back to their defaults but still am not getting any ESC data.

Here’s the p
WR2_Param_3-19-25_10-55.param (18.0 KB)
aram file:

4

Set RPM1_TYPE,0

That’s only needed if you’re using a specific ESC telemetry wire to a UART. Not needed for BDShot.

5

Gotcha, here’s an updated Param list. Still no luck-- going to try a firmware update on the Pixhawk to see if that helps.

WR2_Param_3-19-25_11-25.param (17.9 KB)

6

Try

SERVO_BLH_MASK,0
7

Dumb mistake :sweat_smile: I did not realize that there are two versions of the copter firmware, one “regular” and one “bdshot”

Everything is working now with an upgrade to Arducopter 4.5.7-bdshot

For reference, in Mission Planner > Setup > Install Firmware > Copter V4.5.7 OFFICIAL > Use the dropdown to install the bdshot specific firmware.

bdshot_update_screen
bdshot_update_screen534×392 6.29 KB

1 Like
8

A better method IMO is to download the exact firmware (.apj file) you need from the repository and flash it with Mission Planners “load custom firmware” option.