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Showing posts from February, 2019

Auric: Learning from testing

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It's amazing what you learn when testing in the real world... Auric went out for a long drive last weekend, while things went pretty well, there are always things to learn: 1.  Solving a performance problem Halfway through the long test I noticed that Auric was pulling to the left, and I suspected a motor drive problem.  After putting the machine up on a bench for a closer look I noticed something, well, "green" Upon closer inspection, Auric had decided to become an autonomous lawn mower and managed to wrap a 60cm grass runner around the front left drive.  Side effect was that the motor was loaded down and that caused thermal protection in the driver board to kick in. The final insult was when the imaging detected off-course behaviour and resulted in the motion controller trying to drive the jammed motor even harder, resulting in a vicious cycle. The end result of all of this is twofold.  Firstly, removing said grass solved the problem, and I wish t...

Auric: All about batteries

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Batteries are really important if you're living off them OK, so this is going to be pretty boring, but it is important so bear with me. I learned from my experiments with the self-driving car that battery performance is critical, and to be honest last time I didn't pay enough attention.  I am making up for that oversight this time around. The Lovbio car used a 6V lead-acid battery to run it's motor.  Because that didn't give me too much headroom for my 5V powered electronics I had to run a separate 7.4V LiPo pack (commonly known as a "2S" pack) to run the electronics.  While it worked in the short term and helped the car to meet it's goals, it was not a viable solution . Because Auric is a ground-up design I had the opportunity to address a lot of the shortcomings from the last car and one of those was the power supply.  This time, it's a single battery and it's a big one, a 6200mAh 2S LiPo pack.  Basically it was the highest capacity...