Parameters

Parameters are used in config.h to configure the behavior of the firmware, by enabling/disabling features, or adjusting value.

Battery Management

For parameters related to Battery Management, please visit following wiki section.

Variant specific parameters

Variant specific parameters are covered in the wiki section of for each variant.

Input Calibration

For Parameters related to Input Calibration, please visit following wiki section.

Further Input processing

After the inputs have been mapped to the MIN, MID and MAX value that have been calibrated, following parameters can help adjust the behavior of the firmware.

Deadband

DEADBAND parameter is used to set a dead area around the MIN value that will still map to a zero input value.
This is for example used with PWM variant to prevent jitters at standstill due to signal noise.
It can also help in addition to the auto-calibration if your joystick is not perfectly centered.

Rate limiting

DEFAULT_RATE parameter is used to limit the rate of change of the inputs in the main loop between 2 loop iterations.
This helps smooth out the final ouput to the motor control model.
The default value is 480 in fixed-point, which corresponds to 30 value in single precision.

This means if the input goes from 0 to 300, the firmware will limit the increment to 30 for each loop iteration (5ms)

Iteration	Time	Input Value	Limited Value
0	0ms	0	0
1	5ms	300	30
2	10ms	300	60
3	15ms	300	90
4	20ms	300	120
5	25ms	300	150
6	30ms	300	180
7	35ms	300	210
8	40ms	300	240
9	45ms	300	270
10	50ms	300	300

A rate of 32767 in fixed-point means the value can increase/decrease by an increment of 2047, so basically there is no limiting.
Please don't change this parameter if you don't know what you are doing, this can lead to issues.
⚠ Don't set the RATE parameter higher than 32767, this corresponds to a Negative Rate in single precision value.

Filtering

DEFAULT_FILTER parameter is used to smooth out (low-pass filter) the output value to the motor control.
The default value is 6553 in fixed-point, which corresponds to a filter of 0.1 in single precision.
This means if the input goes from 0 to 300, the output value will be 90% of the previous value + 10% of the new value

Iteration	Time	Input Value	Filtered Value
0	0ms	0	0
1	5ms	300	90% of 0 + 10% of 300 = 30
2	10ms	300	90% of 30 + 10% of 300 = 57
3	15ms	300	90% of 57 + 10% of 300 = 81

A filter of 65535 in fixed-point, which corresponds to 1 in single precision, means no filter will be applied.
You can also define parameter FILTER for a specific variant, it will overwrite DEFAULT_FILTER parameter (e.g. NUNCHUK Variant is using a smoother filter of 3276->0.05 ).

Coefficients

DEFAULT_STEER_COEFFICIENT and DEFAULT_SPEED_COEFFIENT parameters can be used to scale INPUT1 and INPUT2 respectively.
The default value for the speed coefficient is 16384 in fixed-point, which corresponds to 1.0 in single precision, it means INPUT2 is not scaled.
A value of 8192 in fixed-point means the input value is multiplied by 0.5.
A value of 32767 in fixed-point means the input value is multiplied by 2.
A value higher than 32767 in fixed-point means the coefficient is negative(e.g. NUNCHUK variant has a negative STEER_COEFFICIENT).

After the coefficients have been applied, Steer and Speed value are mixed to control left and right motor.
If you don't need steering, you can define STEER_COEFFICIENT parameter as 0, it will overwrite DEFAULT_STEER_COEFFICIENT.

Invert wheel direction

By default, the firmware assumes the wheels are side by side.
You can use INVERT_R_DIRECTION or INVERT_L_DIRECTION parameter to invert the direction of one wheel. (e.g. on a scooter, both wheels are facing the same direction).

Single wheel use

If you only want to use a single wheel/motor, the firmware will go into error mode because it will detect a motor is missing.
Comment out parameter MOTOR_LEFT_ENA or MOTOR_RIGHT_ENA to disable the wheel you don't need.