Beginning of a New Project: The Pmod Racing Ruler

Hello and welcome to the Digilent blog!

Having now conquered (or at least tamed) the force that is gravity, James and his projects are moving onto the next measure of greatness: A Digilent PCB Ruler Racer.

Levitation of a Ping Pong ball.

The idea behind this new project is to create (using Pmods and the PCB Ruler) a small speedster that will bump into solid objects, then stop. James aims to achieve this by using the PmodDHB1 and PmodACL. The PmodDHB1 is a duel H-bridge, capable of driving up to four different motors. James is using it to drive the two motors that connect to the back wheels. The PmodACL will determine whether or not the racer has bumped into an object or not by detecting spikes in acceleration.

In a rare and unprecedented turn of events, the electronics today were working perfectly. As anyone with electrical engineering experience can attest,  this sort of miracle is a precious one.

However despite a strong showing from the circuitry, the mechanical side(s) of the project were not as up to speed. The connection between the front ruler and the front wheels was a bit wayward, and it was preventing the racer from moving as intended (and sometimes from moving at all).

The issue is the precariousness of the connection. The wheels need only be fixed and to prevent the front from dragging on the ground, however, it is extremely difficult to make the contact between the tip of the metal axle and the rectangular front of the ruler secure.


James has tried duct tape but it is not secure enough to withstand more than a few seconds of movement.


And if that wasn’t enough of a headache, when tested the racer has an infuriating habit of rearing up and raising its front wheels before moving forward, then proceeding to slam them down on the ground….triggering the accelerator.


Stay tuned to find out whether or not he finds a solution! Will he stay and drive on with his need for speed? Or will he pursue something else fast but that won’t make him furious?

We will follow James as he tackles these challenges and post updates on his progress. Also if you happen to have any suggestions for solutions to the outlined issues, please feel free to detail your ideas in the comments!



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About Miranda Hansen

I enjoy creative writing, engineering, thinking, building, exploring and sharing with people. Huge aficionado of spending time thinking about things that “don’t matter.” I am very interested in unconstrained creativity. I love cross-discipline ideas and all of their integration into complete original systems. And I like things that do things.

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