MCRobbie

MCRobbie

See more in-depth documentation on the official documentation site.

What is it?

An advanced motor controller with an i2c interface.

That means it is something that you connect to using an i2c interface and it generates the control signals needed by the motor drivers for up to 4 motors. The 'advanced' part is because the controller can take care of acceleration for your motors. So if you are using this to control the wheels of a robot (which is the original application that it was designed for) than you can just send the desired speed and the controller can take care of accelerating to that speed so that the robot moves smoothly.

The controller can provide signals to control up to 4 motors independently. The motor drivers can be either 2- or 3- wire drivers.

Why would I use this?

You may want to use this if you:

• have a limited number of pins for control on your project
• not have enough pins on your Arduino to run as many motors as you need
• want to control motors from a raspberry pi
• want your motors to accelerate without adding programming overhead
• want to use the i2c interface on your controller
• want your control signals to be cleaner than the signals generated by the normal Arduino libraries (see note below)

You may not want to use this if you:

• have plenty of pins
• don't want your motors to do anything other than move at one speed
• don't have an i2c interface on your controller
• have no way to program the controller or to buy a programmed one

Note about Arduino:

The Arduino libraries and boards have worked very well for us. We made this because it is much less expensive (an uno costs about 20 euro, the PIC used costs around 2 euro), the control signals generated by Arduinos have been somewhat inconsistent when rapidly changing motor speed, and, the PIC is much smaller than the Ardunio boards and we can integrate it into our custom PCB designs.

How do I use this?

We are in the process of creating detailed tutorials.

At the moment the only hardware this has been tested on is a PIC18f14k50 controller. It is an 8-bit microcontroller sold by microchip. If you have a compatible programmer (I am using the PICKit 3) you can just load this code and program the controller normally. If you order from microchip they can program the device before sending it to you, although I have not yet tried this.

This same code should work without changes on the PIC18f14k22, and possibly on other PIC18 chips, but that has not yet been tested. One of our priorities now is to port this code onto some Atmel chips that can be programmed using an Arduino, and into code that can be put on an Arduino directly. The purpose of this controller is that it is very cheap (about 2 euro for the chip and it doesn't require any external components), a lot of people have Arduinos already so using one could be a cheaper option for some.

An important note

This is a controller, not a driver. The controller generates the signals needed to make a motor move in the direction and at the speed you want, a motor driver is needed to supply the power to the motor.