As always with life, things happen and I have been distracted by work and family. I have been slowly working on the Brick Buddy 2 platform. The layout is now complete as the picture below shows.
You can see the TYPE C connector on the right, the Bluetooth module in the center top and the brick interface on the left.
The Brick Interface has four motor connectors using the same style connector as before. Above that are the four input connectors, using a similar style connector only smaller. What is good about this connector style is that pre-built cables are readily available from Digi-Key. Above that are the 10 connectors for the LEDs. The first nine are connected to the LP5569 LED controller and thus will have multiple possibilities in lighting control. This uses the same connector that BrickStuff is using with their LED product line.
In the center left is the connector for the Mass Storage, MP3 player and amplifier, but we will go into further detail about this later...
Finally I changed the external power connector to the same one as the motor connection, since this breaks out to a Power Functions connector. It allows the Brick Buddy 2 to receive power from any Lego power source.
In my last post I talked about design decisons that needed to be made. Here is what happened since then, I went with two spare pins where both are generic inputs and one of them can be an Interrupt input. If needed I also still have the two programming pins and the Rx pin in the console port.
The motor control pins were complex. There are only 5 PWM (Pulse Width Modulated) outputs in this version of the PIC32 microcontroller. You could control the motors with one PWM pin on one side of the motor and a static line on the other side of the motor, but I am worried about reliability. The pins were chosen so that the PWM outputs can be mapped to either side. Not sure how responsive this is going to be, but I hope it will work.
Next time I will be describing the brick interface in more detail.
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