SERVO_BLH_ parameters

12 parameters in the SERVO_BLH_ family. ArduCopter 4.7 only — other vehicles share many of these names but not always the same ranges or meanings.

SERVO_BLH_3DMASK

BLHeli bitmask of 3D channels

Mask of channels which are dynamically reversible. This is used to configure ESCs in ‘3D’ mode, allowing for the motor to spin in either direction. Note that setting an ESC as reversible with this option on AM32 will result in the forward direction of the ESC changing. You can combine with parameter with the SERVO_BLH_RVMASK parameter to maintain the same direction when the ESC is in 3D mode as it has in unidirectional (non-3D) mode.

Reboot required	Yes — the change takes effect after a reboot.
User level	Advanced

Bitmask

Value	Meaning
0	Channel1
1	Channel2
2	Channel3
3	Channel4
4	Channel5
5	Channel6
6	Channel7
7	Channel8
8	Channel9
9	Channel10
10	Channel11
11	Channel12
12	Channel13
13	Channel14
14	Channel15
15	Channel16
16	Channel 17
17	Channel 18
18	Channel 19
19	Channel 20
20	Channel 21
21	Channel 22
22	Channel 23
23	Channel 24
24	Channel 25
25	Channel 26
26	Channel 27
27	Channel 28
28	Channel 29
29	Channel 30
30	Channel 31
31	Channel 32

SERVO_BLH_AUTO

BLHeli pass-thru auto-enable for multicopter motors

If set to 1 this auto-enables BLHeli pass-thru support for all multicopter motors

Reboot required	Yes — the change takes effect after a reboot.
User level	Standard

Values

Value	Meaning
0	Disabled
1	Enabled

SERVO_BLH_BDMASK

BLHeli bitmask of bi-directional dshot channels

Mask of channels which support bi-directional dshot telemetry. This is used for ESCs which have firmware that supports bi-directional dshot allowing fast rpm telemetry values to be returned for the harmonic notch.

Reboot required	Yes — the change takes effect after a reboot.
User level	Advanced

Bitmask

Value	Meaning
0	Channel1
1	Channel2
2	Channel3
3	Channel4
4	Channel5
5	Channel6
6	Channel7
7	Channel8
8	Channel9
9	Channel10
10	Channel11
11	Channel12
12	Channel13
13	Channel14
14	Channel15
15	Channel16
16	Channel 17
17	Channel 18
18	Channel 19
19	Channel 20
20	Channel 21
21	Channel 22
22	Channel 23
23	Channel 24
24	Channel 25
25	Channel 26
26	Channel 27
27	Channel 28
28	Channel 29
29	Channel 30
30	Channel 31
31	Channel 32

SERVO_BLH_DEBUG

BLHeli debug level

When set to 1 this enabled verbose debugging output over MAVLink when the blheli protocol is active. This can be used to diagnose failures.

User level

Standard

Values

Value	Meaning
0	Disabled
1	Enabled

SERVO_BLH_MASK

BLHeli Channel Bitmask

Enable of BLHeli pass-thru servo protocol support to specific channels. This mask is in addition to motors enabled using SERVO_BLH_AUTO (if any)

Reboot required	Yes — the change takes effect after a reboot.
User level	Advanced

Bitmask

Value	Meaning
0	Channel1
1	Channel2
2	Channel3
3	Channel4
4	Channel5
5	Channel6
6	Channel7
7	Channel8
8	Channel9
9	Channel10
10	Channel11
11	Channel12
12	Channel13
13	Channel14
14	Channel15
15	Channel16
16	Channel 17
17	Channel 18
18	Channel 19
19	Channel 20
20	Channel 21
21	Channel 22
22	Channel 23
23	Channel 24
24	Channel 25
25	Channel 26
26	Channel 27
27	Channel 28
28	Channel 29
29	Channel 30
30	Channel 31
31	Channel 32

SERVO_BLH_OTYPE

BLHeli output type override

When set to a non-zero value this overrides the output type for the output channels given by SERVO_BLH_MASK. This can be used to enable DShot on outputs that are not part of the multicopter motors group.

Reboot required	Yes — the change takes effect after a reboot.
User level	Advanced

Values

Value	Meaning
0	None
1	OneShot
2	OneShot125
3	Brushed
4	DShot150
5	DShot300
6	DShot600
7	DShot1200

SERVO_BLH_POLES

BLHeli Motor Poles

This allows calculation of true RPM from ESC’s eRPM. The default is 14.

Range	1 to 127
Reboot required	Yes — the change takes effect after a reboot.
User level	Advanced

SERVO_BLH_PORT

Control port

This sets the mavlink channel to use for blheli pass-thru. The channel number is determined by the number of serial ports configured to use mavlink. So 0 is always the console, 1 is the next serial port using mavlink, 2 the next after that and so on.

User level

Advanced

Values

Value	Meaning
0	Console
1	Mavlink Serial Channel1
2	Mavlink Serial Channel2
3	Mavlink Serial Channel3
4	Mavlink Serial Channel4
5	Mavlink Serial Channel5

SERVO_BLH_RVMASK

BLHeli bitmask of reversed channels

Mask of channels which are reversed. This is used to configure ESCs to reverse motor direction. Note that when combined with SERVO_BLH_3DMASK this will change what direction is considered to be forward.

Reboot required	Yes — the change takes effect after a reboot.
User level	Advanced

Bitmask

Value	Meaning
0	Channel1
1	Channel2
2	Channel3
3	Channel4
4	Channel5
5	Channel6
6	Channel7
7	Channel8
8	Channel9
9	Channel10
10	Channel11
11	Channel12
12	Channel13
13	Channel14
14	Channel15
15	Channel16
16	Channel 17
17	Channel 18
18	Channel 19
19	Channel 20
20	Channel 21
21	Channel 22
22	Channel 23
23	Channel 24
24	Channel 25
25	Channel 26
26	Channel 27
27	Channel 28
28	Channel 29
29	Channel 30
30	Channel 31
31	Channel 32

SERVO_BLH_TEST

BLHeli internal interface test

Setting SERVO_BLH_TEST to a motor number enables an internal test of the BLHeli ESC protocol to the corresponding ESC. The debug output is displayed on the USB console.

User level

Advanced

Values

Value	Meaning
0	Disabled
1	TestMotor1
2	TestMotor2
3	TestMotor3
4	TestMotor4
5	TestMotor5
6	TestMotor6
7	TestMotor7
8	TestMotor8

SERVO_BLH_TMOUT

BLHeli protocol timeout

This sets the inactivity timeout for the BLHeli protocol in seconds. If no packets are received in this time normal MAVLink operations are resumed. A value of 0 means no timeout

Units	s
Range	0 to 300
User level	Standard

SERVO_BLH_TRATE

BLHeli telemetry rate

This sets the rate in Hz for requesting telemetry from ESCs. It is the rate per ESC. Setting to zero disables telemetry requests

Units	Hz
Range	0 to 500
User level	Standard