PRLS Hardware Guide

This page provides guides for physically setting up the electronics and mechanical components provided in the Professional Robotics Learning System (PRLS).

Electronics Guides

Warnings

To prevent damage to the kit electronics, please take the following precautions:

  1. Turn off the power before plugging / unplugging cables
  2. Ensure that all cables are plugged in with the correct orientation prior to applying power to the system
  3. Take care not to allow any short circuits in the electronics. For example, be sure not to power the electronics while they are resting on metal surfaces, and design electronics mounts such that the electronics don’t come in direct contact with any metal screws / structural parts.

System Power

The Module Core is powered from a single source, connected via the Phoenix connectors highlighted in the left picture. The port closer to the top of the board must be positive voltage, while the port closer to the bottom must be ground. It is very important not to plug the power cable in backwards, as this will damage the board. The Module Core and TR Expansion regulate voltages and distribute the power to all the electronics in the PRLS.

The power to the motors and servos can be turned on and off by attaching a switch to the port shown on the right. This allows users to test sensors / algorithms without worrying about the robot driving away. If this functionality is not required, the motor power can also be constantly enabled by simply connecting the two pins using a jumper or wire.

JTAG Programmer

The Module Core is programmed using JTAG, via the ST-LINK adapter (left). The adapter’s ribbon cable must be connected to the JTAG port shown in the right image, after which the adapter can be connected to a PC with a USB cable.

Reset Button & LEDs

The board can be manually reset using the button shown in the left image. This will reset the microcontroller, starting the program over from the beginning.

The Module core also includes a power LED, and three status LEDs (right image). The power LED will be on whenever input power has been supplied to the board. The status LEDs can be set within the user’s program, and can indicate anything from errors to program status.

Motor Submodules

The Motor Submodules provided in the kit (left) can be connected to the ports shown in the right image. Be sure that the orientation of the cable is correct by checking the diagram printed near the ports: The yellow battery line on the cable should be in the top-left corner of the Module Core’s port, while the empty slot in the cable (no-connect, NC) should be in the lower right. Similarly, the battery connection should be closest to the large cylindrical capacitor on the Motor Submodule, while the empty cable slot should be farthest away.

 Servos

The servos provided in the kit (left) can be connected to the ports shown in the right image. Be sure that the orientation of the cable is correct by checking the diagram printed near the ports: The black ground wire should be closer to the top of the board, while the yellow signal wire should be closer to the bottom of the board.

Switches

The switches provided in the kit (left) can be connected to the ports shown in the right image. Since the switches simply connect the two pins when they are pressed, the orientation of the connector does not matter.

Distance Sensors

The distance sensors provided in the kit (left) can be connected to the ports shown in the right image. Be sure that the orientation of the cable is correct by checking the diagram printed near the ports: The red power wire should be to the right side of the board, while the white clock signal wire should be to the left. On the distance sensor board, ensure that the red power wire is attached to the pin labeled VIN, while the white clock signal wire is attached to the SCL pin.

Line Sensors

The line sensors provided in the kit (left) can be connected to the ports shown in the right image. Note, however, that the two ports closest to the top of the board can also be used for the speaker connections (see Speaker section below), so the bottom five ports should typically be filled before the top two are used. Be sure that the orientation of the cable is correct by checking the diagram printed near the ports: The black ground wire should be to the left side of the board, while the green analog signal wire should be to the right. On the line sensor board, ensure that the black ground wire is attached to the pin labeled GND, while the green analog signal wire is attached to the OUT pin. Also note that, while the microphone board connects to the same set of ports, the cables are not interchangeable.

Microphone

The microphone provided in the kit (left) can be connected to the ports shown in the right image. Note, however, that only the two ports closest to the top of the board can also be used for the speaker connections (see Speaker section below), so the bottom five ports should typically be filled before the top two are used. For compatibility with the PRLS example code, the microphone should be plugged into the topmost port. Be sure that the orientation of the cable is correct by checking the diagram printed near the ports: The black ground wire should be to the left side of the board, while the green analog signal wire should be to the right. On the microphone board, ensure that the red power wire is attached to the pin labeled VCC, while the green analog signal wire is attached to the AUD pin. Also note that, while the line sensor board connects to the same set of ports, the cables are not interchangeable.

Speaker

The speaker and amplifier board provided in the kit (left) can be connected to the ports shown in the right image. This board is different from most of the other electronics in that it requires two separate connections: one for power and one for analog signal. Be sure that the orientation of the cables are correct by checking the diagram printed near the ports: The signal cable should be plugged into one of the upper two analog ports (right box in right image), with the black ground wire to the left side of the board and the green analog signal wire to the right. For compatibility with the PRLS example code, the signal cable should be plugged into the second port. The power cable can be plugged into any of the I2C ports (left box in right image), with the red wire towards the right side of the board, and the empty slots to the left.

Mechanical Guides

Board Mounting

The Module Core can be mounted to a robot using three M3 screws through the holes shown above. The provided spacers should be used between the Module Core and expansion board to ensure secure mounting without damaging the connectors.

Wheel Mounting

Wheels (and other hardware) can be mounted to the end of the motor using four M2 screws.

Servo Horn Mounting

A variety of servo horns are available for mounting on the end of the servos. Be sure to only use the black screw provided with each servo to mount the horns to the servos, as some of the other screws in the kit will damage the internal components of the servo if forced in.