Specifications

Rev B.1 (September 2020)

Dimensions

Parameter	Value	Comments
Degrees of Freedom (DoF)	22
Legs DoF (each)	6	ankle pitch and roll, knee yaw and pitch, hip pitch and roll
Legs Actuators	6 x 2XL430	each leg contains 3 2XL430-W250 Dynamixel Actuators
Arms Dof (each)	4	shoulder pitch and roll, elbow yaw and pitch
Arms Actuators	8 x XL430	each arm contains 4 XL430-W250 Dynamixel Actuators
Head DoF	2	pitch and yaw
Head Actuators	1 x 2XL430	one 2XL430-W250 Dynamixel Actuator

Parameter	Value	Comments
Batteries	2 x 2500mAh 3S LiPo batteries	Batteries are located in the feet and are hot-swap; there is no need to turn off the main controller to change the batteries
External power	2.5mm power jack 12V	Optionally the robot can be powered with a 12V power adapter using a standard 2.5mm barrel jack
Autonomy	3 hours	(preliminary estimates)
Monitoring	voltage	ADC used to provide reading for Dynamixel bus voltage, 5V railing and 3.3V railing.

Parameter	Value	Comments
Main controller	Raspberry Pi CM4 8GB RAM	We use the Waveshare CM4 IO Board A to expand the peripherals.
Add on board	Robotics HAT for Raspberry Pi	The board includes: 1. high speed dual Dynamixel bus 2. IMU (Gyroscope and Accelerometer) 3. 5V 3A power switch for RPi 4. ADC for monitoring power 5. WM8960 codec with stereo mics and speakers 2 x 1W output 6. PWM fan control 7. USB to UART converter for direct USB console access for RPi
Foot sensors	SPR2010	Each foot includes a circuit that: 1. ideal diode allowing LiPo batteries hot-swap 2. battery voltage and current monitoring with 4 LED level indicator, low voltage buzzer and very low voltage cut-off 3. four force sensing resistors (FSR) for accurate positioning of the CoM 4. Dynamixel bus communication interface up to 2Mbs
Display	Waveshare 2.4" TFT display	A 2.4'' 320x 240 TFT display connected on SPI with console support
Camera	Two RPi FPC Cameras MIni Size	Connected on the two CSI camera connectors on the IO Board, 69.8 degree FoV, max 1080p30
WiFi	Built-in 5Ghz frequency -WiFi and second dongle	The built in configures a low-latency (5GHz band) Access Point (AP) and the second Wi-Fi can connect to an exiting infrastructure. It is especially efficient for running distributed ROS nodes
Bluetooth	Builtin Bluetooth 5.0 BLE	Bluetooth keyboard for remote control and interface navigation.

Parameter	Value	Comments
OS	Raspbian (Debian Buster)	Kernel drivers added for: - SC16IS762 (SPI to UART dual bus used for Dynamixel actuators) - ST7789V (TFT display) - WM8960 (sound) - ADS1015 (for voltage monitoring ADC) - fan_control
Software	ROS Noetic	ROS Noetic is installed using RoboStack
Custom ROS packages	here	- Dynamixel controller - UI for robot TFT - URDF with support for RViz and Gazebo - "director" package that that process scripted moves - vision (in progress)

There are a number of exciting upgrades to the platform that we expect to deliver soon:

Area	Improvement
2nd Controller	Add a second controller Raspberry Pi CM4 in the head for vision processing with dedicated add-on board for cameras, power, fan and console access.
Coral support	Integrate a Coral Board M.2 (B+M version) using the M-key connector on the Waveshare IO Board