Kbot Firmware

From scratch firmware rewrite in python. Intent is to keep it as small and as simple as possible. Minimize complexity --> Minimize bugs.

Control loop overview

Loop runs at 50Hz. Roundtrip time is around 4.5ms. We then wait 15.5ms to get to 50hz. The actuators independently run a PD controller at 1kHz.

Loop:

• Read sensor values from actuators, imu, etc
• Forward pass through policy network
• Send policy actions to motors

Installation

git clone https://www.github.com/kscalelabs/pyfirmware
cd pyfirmware

make setup # installs conda env
conda activate firmware
pip install .

Usage

Test the actuators with a simple sinewave at low pd gains:

kbot-sine

Run Kscale policies:

kbot-run

Run your policies:

POLICY_DIR=<your-policy-dir> kbot-run

Commands

Kbot accepts keyboard (wasd) or UDP commands.

Keyboard Control

Key(s)	Command	Change
w / s	x-vel	±0.1
a / d	y-vel	±0.1
q / e	yaw ω	±0.1
= / -	base height	±0.05
r / f	base roll	±0.1
t / g	base pitch	±0.1
0	reset cmds	0
z	wave	-
x	salute	-
c	raise arms	-
v	boxing guard	-
b	left punch	-
n	right punch	-
i	base cone	-

UDP Control

Kbot accepts two types of UDP commands:

• Policy commands: for arm teleop while walking/standing
• Direct joint commands: for individual joint control like grippers or upper-body-only robots

⚠️ Direct joint commands override the full body controller and give you direct control.

1. Policy Commands

Command	Default
xvel	0
yvel	0
yawrate	0
baseheight	0
baseroll	0
basepitch	0
rshoulderpitch	0
rshoulderroll	0
rshoulderyaw	0
relbowpitch	0
rwristroll	0
lshoulderpitch	0
lshoulderroll	0
lshoulderyaw	0
lelbowpitch	0
lwristroll	0

2. Joint Commands

Full Name
dof_left_shoulder_pitch_03
dof_left_shoulder_roll_03
dof_left_shoulder_yaw_02
dof_left_elbow_02
dof_left_wrist_00
dof_left_wrist_gripper_05
dof_right_shoulder_pitch_03
dof_right_shoulder_roll_03
dof_right_shoulder_yaw_02
dof_right_elbow_02
dof_right_wrist_00
dof_right_wrist_gripper_05
dof_left_hip_pitch_04
dof_left_hip_roll_03
dof_left_hip_yaw_03
dof_left_knee_04
dof_left_ankle_02
dof_right_hip_pitch_04
dof_right_hip_roll_03
dof_right_hip_yaw_03
dof_right_knee_04
dof_right_ankle_02

Example

Send JSON-formatted UDP commands to port 10000 on localhost (127.0.0.1) or robot IP.

{
   "type": "normal",
    "commands": {
        // Policy commands
        "xvel": 0.5,
        "yvel": 0.0,
        "yawrate": 0.0,
        "baseheight": 0.8,
        "baseroll": 0.0,
        "basepitch": 0.0,
        // Direct joint commands
        "dof_left_wrist_gripper_05": 0.57
    }
}

{
    "type": "reset"
}

Dev usage (internal use only)

⚠️ WARNING: BETA POLICIES ⚠️

Untested, unlabeled, incompatible policies that WILL break your bot:

kbot-deploy [--gstreamer] [--command-source keyboard|udp]

Known bugs

• critical faults raise an error, stopping the firmware, rather than gracefully handling