ACADA Robotics • Documentation • ROSRider • Pinmaps and Connections

> Pinmaps and Connections

Left Motor Connector

This standard 6-wire encoder motor connector is compatible with various motors and can be used with standard cables.

Right Motor Connector

The right motor connector is a mirrored version of the left motor connector.

Servo Connector

The ROSRider card can control two standard servos. The servos are powered by auxiliary power, which must be enabled via software before use.

AUX Power Port

Software controllable auxillary power port, will generate 5V when turned on.

Power Control Port

This is an internal connector, that can be used to control buttons on the board remotely. The connector is not soldered, and left for future expansion.

Communications Port

This pin header can be used for both I2C0 and serial port communication. The reset pin is decoupled with a 150nF capacitor to isolate it from the internal reset.

I2C QWIC Port A

This is a standard QWIC port, which can be connected by a standard QWIC cable. The VCC from QWIC cable is used to wake up the board from hibernate state and is isolated from device.

I2C QWIC Port B

There are two identical QWIC ports, that can be used to connect other QWIC devices, or piggyback another ROSRider card.

Serial Port

Serial Port debug connector, this can be connected to ROS2RPI card for accessing serial port. DO NOT connect to a QWIC port, as this may short the power supply.

Power Connector

XT30 Power Connector. Apply maximum 12V.

Backup Battery

Use CR1225 3V coin battery.

Connecting ROSRider to Raspberry PI

This wiring diagram illustrates direct I2C communication with the Raspberry PI. To enable I2C communication on a Raspberry Pi running Ubuntu, first ensure I2C is enabled by adding dtparam=i2c_arm=on to /boot/firmware/config.txt and rebooting.

Use jumper wires to connect your Raspberry PI using GPIO pins 2 (SDA) and 3 (SCL). After installation, verify the connection using sudo i2cdetect -y 1 to detect connected devices.

Detecting I2C Devices

For troubleshooting purposes, you may want to detect I2C devices connected to your computer. To do this, you can use the i2cdetect command in the terminal. Run the following command to install i2c-tools: sudo apt install i2c-tools. Use the i2cdetect command to scan the I2C bus and identify connected devices:

sudo i2cdetect -y -r 1

This command will display a table of I2C addresses. The default address of the ROSRider is 0x3C, and the default address of the ROS2RPI card is 0x20. If you only have a ROSRider connected directly, you should only see the address 0x3C.

Connecting ROSRider to NVIDIA Jetson

The NVIDIA Jetson has two I2C ports accessible via the header. To ensure proper communication with I2C devices, it’s crucial to configure the I2C voltage level. This is accomplished using a jumper (J514) on the board. To select 3.3V I2C, position the jumper accordingly. To ensure proper I2C communication, verify that I2C is enabled at the kernel level and that your user account has the necessary permissions to access the I2C bus on the host computer.

There are two I2C ports on the Jetson AGX:

Jetson AGX I2C Port 0

Jetson AGX I2C Port 1

Next Chapter: Updating Firmware

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