Technical Specifications

The VMX-pi circuit board and official firmware provide inertial and magnetic measurements, with a range, accuracy and update rate as described on this page, as well as a broad range of I/O and Digital Communication capabilities and flexible Power Management.

Note that certain IMU performance specifications are only valid after a start-up Gyroscope/Accelerometer Calibration period, during which time the VMX-pi circuit board must be held still.

Additional details can be found in the VMX-pi-datasheet.

Additionally, the specifications for the connector cables with come with each VMX-pi are also documented on this page.

Electrical Specifications
Input Voltage: 6-16V DC
Output Voltages: 5V, 3.3V
Protection Features: Input Voltage Clamps;
Under-voltage management;
Output Current Limiting
Communications Interface: USB, I2C, SPI, CAN,UART
Power Connector: 2-Pin JST VH Connector
USB Connector: USB Micro-B
IMU Performance Specifications
Startup Calibration Period: 15 seconds
Gyro Sensitivity: +/- 2000 degrees/sec
Accel Sensitivity: +/- 2 g
Magnetometer Sensitivity: 1.3 Gauss
Yaw angle accuracy: ~1 degree of drift/minute
Yaw angle accuracy (when still): ~.25 degree of drift/minute
Orientation Data Update Rate: 4-200 Hz
Magnetometer Raw Update Rate: 4 Hz
Magnetometer Angular Accuracy: +/- 2 degrees
Pitch/Roll Angular Accuracy: +/- 1.5 degrees
Analog Input Specifications
Number of Channels: 4
Resolution: 12 bits
Digital IO Specifications
Total Number of Channels: 30
Number of Input-capable & Interrupt-capable Channels: 25
Number of Output-capable & PWM-capable Channels: 27
Number of Quadrature Encoder Channel Pairs (HW-decode): 5
Digital Communication Specifications
CAN Protocol (2.0b) 1mbps
SPI Protocol 8 Mhz
I2C Protocol 400 kHz
USB Protocol 12 mbps
UART Protocol 115 kbps

 

Battery Adapter Cable Specifications
Input Voltage: 6-16V DC
Wire Gauge: 20 AWG (rated for use at 3A)
VMX-pi Connector: JST-VH
Wire Colors Red (power), Black (ground)
Free End: Stripped and Tinned
Cable Length: 25cm
 The Battery Adapter Cable provides power for VMX-pi, Raspberry Pi and external devices – and is designed to be easily connect VMX-pi to a robot battery or power distribution switch.

 

Wall-wart Adapter Cable Specifications
Input Voltage: 6-16V DC
Wire Gauge: 20 AWG (rated for use at 3A)
VMX-pi Connector: JST-VH
Wire Colors Red (power), Black (ground)
Wall-wart Jack Center Positive; 2.1mm Inner Diameter; 5.5mm Outer Diameter
Cable Length: 25cm
 The Wall-wart Adapter Cable provides power for VMX-pi, Raspberry Pi and external devices – and is designed to be used with a standard, center-positive AC-DC Adapter which outputs up to 3A at from 6-16VDC.  Note:  an AC-DC Adapter must be purchased separately.