Canandgyro

Message/wire format spec, version 2024-offseason.

The device spec for Redux products will not change in a backwards-incompatible fashion in-season, from the first official release for a given year until after the FIRST Championship.

General properties

Property	Value
FRC CAN Device Type	0x4
DBC File	Link
Inherits from	[CanandDevice]

The DBC files assumes a device id of 0. For more information on the CAN device type, see CanandDevice

Messages

Message summary:

API Index	Message	Description
0x1f	YAW_OUTPUT	Yaw angle frame
0x1e	ANGULAR_POSITION_OUTPUT	Angular position quaternion frame
0x1d	ANGULAR_VELOCITY_OUTPUT	Angular velocity frame
0x1c	ACCELERATION_OUTPUT	Acceleration frame
0x1b	CALIBRATE	Trigger Calibration
0x1a	CALIBRATION_STATUS	Calibration Status
0xb	ENUMERATE	Device enumerate response
0x7	PARTY_MODE	Party mode
0x6	STATUS	Status frame
0x5	CLEAR_STICKY_FAULTS	Clear device sticky faults
0x4	REPORT_SETTING	Setting value report from device
0x3	SET_SETTING	Update setting on device
0x2	SETTING_COMMAND	Setting control command

YAW_OUTPUT

Periodic frame with the Canandgyro’s yaw value at full 32-bit float precision in radians.

Properties

Property	Value
API Index	0x1f
Message length	6 bytes
Transmission direction	Device -> robot
Frame period setting	YAW_FRAME_PERIOD
Default frame period	10 milliseconds

Signals

Signal name	Signal type	Optional	Description
yaw	yaw	❌	Yaw value

ANGULAR_POSITION_OUTPUT

Periodic frame with an angular position quaternion. The quaternion is normalized and all values are scaled between -1.0 to 1.0 inclusive.

Properties

Property	Value
API Index	0x1e
Message length	8 bytes
Transmission direction	Device -> robot

Signals

Signal name	Signal type	Optional	Description
w	quat16	❌	Quaternion w term
x	quat16	❌	Quaternion x term
y	quat16	❌	Quaternion y term
z	quat16	❌	Quaternion z term

CALIBRATE

Manually triggers gyro calibration. This takes about 5 seconds.

Properties

Property	Value
API Index	0x1b
Message length	8 bytes
Transmission direction	Robot -> device

Signals

Signal name	Signal type	Optional	Description
calibration_type	CALIBRATION_TYPE	❌	Calibration type
reserved	pad56_t	❌	Reserved

Settings

SET_YAW

Updates the yaw (Z-axis) rotation with the new sent angular position.

$$ \left[\cos\left(\frac{1}{2}(\phi_n - \phi)\right) + \sin\left(\frac{1}{2}(\phi_n - \phi)\right)\hat{\mathbf{k}}\right] \cdot \left(w + x \hat{\mathbf{i}} + y\hat{\mathbf{j}} + z\hat{\mathbf{k}}\right) $$

Property	Value
Setting index	0xfb
Type	yaw
Default value	n/a
Readable	❌
Writable	✅
Resets on factory default	❌

GYRO_ZRO_OFFSET_TEMPERATURE

Saved temperature associated with the saved x/y/z-axis zero-motion angular velocity offset.

Property	Value
Setting index	0xf2
Type	rfloat32
Default value	25
Readable	✅
Writable	✅
Resets on factory default	❌

Types

yaw

Yaw frame data. The absolute (single-turn) yaw is broadcast in radians between -pi inclusive and pi exclusive. Multiturn yaw can be computed by taking $\text{yaw} + \text{wraparound} * 2\pi$.

Name	Type	Default value	Description
yaw	float32_t	0.0	Yaw angle
wraparound	int16_t	0	Wraparound counter

faults

Flag index	Flag name	Default value	Description
0	power_cycle	0	Device first boots.
1	can_id_conflict	0	CAN id conflict.
2	can_general_error	0	CAN general error.
3	out_of_temperature_range	0	Out of temperature range (0-70°C).
4	hardware_fault	0	Hardware fault.
5	calibrating	0	Device is currently calibrating.
6	angular_velocity_saturation	0	Saturation of angular velocity.
7	acceleration_saturation	0	Saturation of acceleration.

Enums

CALIBRATION_TYPE

Enum index	Variant name	Description
0x0	NORMAL	Normal calibration routine
0x1	SAVE_ZRO	Save ZRO at calibration complete
0x2	TEMP_CAL_0	Temperature calibrate slot 0
0x3	TEMP_CAL_1	Temperature calibrate slot 1