The Brain Box

The brain box is the center of the kit, it controls power, provides you with useful electronics and is where your code runs. Do NOT open the brain box unless given written permission by Hills Road RoboCon.

The brain box

Power

The distributes power to the robot from the battery. It provides both 12V and 5V power out. All power must go through the brain box and the fuse should never be replaced.

The On|Off switch also plugs into the BrainBox as well as the Start button which is used to start your robot code running.

Motors & 12V Power

The specifications for the motor board can be found here, however to summarize:

Condition per channel Maximum Value
Continuous current 10A
Peak current (10 seconds) 30A
Operating Voltage 12V

TIP

You can toggle the 12V which allows you to turn 12V devices on and off easily. However this will also cut power to the motor board.

GPIO

GPIO - Out

All of the Brain boxes GPIO pins are connected in-series with a 1K Ohm resistor, to provide current limiting. This means that you can plug devices such as LED's straight into your brain box.

Nominally they operate at 5V but depending on your load the true output will vary. You can calculate the voltage you will get across your load by measuring its resistance, then doing the sum:

(5*Load_resistance)/(Load_resistance+1000)

GPIO - In

We advise against you using analogue inputs with an impedance (You can think of impedance as "effective resistance in an analogue circuit") of greater than 9K Ohm's as this will result in values which do not necessarily correspond to what you'd expect.

If you need to sense something with an impedance of more than 9K then you will need to use an Op-amp to buffer the input. If you would like more details on how to do this please contact us on the forums.

GPIO - Limits

Do not try and sink or source more than 25mA into the brainbox's GPIO, it may damage some of the internal components.

PWM Pins

PWM (Pulse Width Modulation) is a technique used for sending signals to a device for how much it should do a thing. This could be how fast to spin a motor, or the position to turn an RC Servo to. It does this by sending regular pulses, which vary in width. The length of the pulse tells the device how much to do the thing. If you are interested you can find out more about using PWM for control here.

Please note you will not be able to drive large motors over the PWM pin's supplied as the maximum which they can supply is 3A.

The PWM pins ranges:

Value Pulse
0 1.5ms
100 2ms
-100 1ms
178 2.39ms
-178 0.61ms

Pin Out

USB's

USB's

Motors

Motors

GPIO

GPIO

Front

Front

Expansion I2C, UART & USB

For expansion please see the expansion page.