October 2009 - Micromouse Online

Decimus 2 takes shape

Post author:Peter Harrison
Post published:October 28, 2009
Post category:Micromouse
Post comments:1 Comment

Decimus has been running reasonably well and each competition sees the plucky little micromouse improving in some way or another. It is clear though that it is not going to be fast enough to compete in South East Asia with any great chance of success. There are at least two faults on it. One is a damaged motor and another, I think, is a dry-joint somewhere on the PCB. Every so often, it will just do something unexpected like turn through a completely wrong angle. When I made Decimus, I ordered extra boards. This week the new motors came so, with only a short time to the all-Japan contest, I am trying to put another mouse together….

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Another STM32 Project Template

Post author:Peter Harrison
Post published:October 20, 2009
Post category:STM32
Post comments:3 Comments

Earlier this year, I wrote about the fun I had setting up the GCC ARM compiler to run under MAC OS X. This kept me occupied for a few days and, eventually, I got it all working. Francois Gervais read the post and kindly offered to share his recipe for building ARM Cortex M3 projects using the GCC compiler. Read on for his notes about the project template…

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Bi level stepper driver

Post author:Peter Harrison
Post published:October 1, 2009
Post category:Hardware
Post comments:4 Comments

At the 2007 Minos micromouse conference, Martin Barratt gave a talk about his stepper motor driving scheme. For best performance, steppers really need to be driven by a high voltage. However, the current will need to be limited to prevent the motor overheating. Normally this is done with dropper resistors which waste all the energy or with chopper drives that can be relatively complex. Martin has an alternative approach that provides the high voltage needed to produce fast step rates and the low current needed to reduce dissipation and keep the battery size under control.

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