Archive for the ‘decimus’ Category
Tuesday, March 25th, 2008
This micromouse thing is a bit tricky. I have not been happy with the accuracy of the results I have been getting with Decimus. Occasionally, a move is significantly shorter, or longer than intended. Looking at the code does not help - either the code is fine or I just ...
Posted in Hardware, decimus, micromouse | No Comments »
Monday, March 24th, 2008
It is true, I am losing my grip. A while ago I posted a link to a Japanese site demonstrating the grip available from a particular micromouse. A common way of doing this is to lock the wheels and place the mouse on a tilting surface. As the slope ...
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Sunday, March 23rd, 2008
Time to do some tuning of the motion control parameters in Decimus. First I wanted to get some idea of how it is behaving with the initial settings. I have added a simple flight recorder function. A 4 kB buffer can hold up to 2000 integers. These are placed in ...
Posted in decimus, micromouse | 1 Comment »
Saturday, March 22nd, 2008
After a bit of a break, I have done some more work on Decimus, my DC micromouse. With all the peripherals tested and working, I have been concentrating on the motion controller or profiler. This has turned out to be harder than I expected. The basic idea is simple ...
Posted in Primus, decimus, micromouse | No Comments »
Sunday, February 24th, 2008
This one was pretty stupid really. The motor drivers are H-bridges made from complementary pairs of MOSFET (the Zetex ZXMC3A16DN8 (datasheet). These need a proper driver chip to ensure good turn-on and turn-off times because of the gate capacitance. for the driver, I used the common Maxim MAX4427 (datasheet). There ...
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Saturday, February 23rd, 2008
It was all getting too awkward. A bit of short sighted design on my part had the Nokia LCD sharing an SPI port with the motor encoders. This meant that I had to turn off the encoders to write to the LCD. While no motion information would be lost by ...
Posted in decimus | 5 Comments »
Thursday, February 21st, 2008
Now that Decimus has all its bits fitted, it is time to get on with the more serious business of driving it about. The basic code for the motor PWM driver has been tested and suitable drive commands can be sent to them. Since this is a PWM system, a ...
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Thursday, February 21st, 2008
The LS7366 is a 32 bit counter with a direct interface for quadrature signals from incremental encoders. There is also an index channel for marker functions. The interface to the microcontroller is SPI mode 0 making it relatively easy to drive with a variety of common controllers. Decimus has ...
Posted in decimus | 4 Comments »
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