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Feb 26, 2013, 05:39 AM
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Stm32f4 pwm


So the STM32F4 had another linker anomaly where an object file had to be near the start or 3 of the PWM pins would stop working after calling a routine jump. In the past, complete crashes were caused by 32 bit jumps being called the wrong way in 16 bit ARM thumb instructions. There seem to be more cases where the compiler isn't handling 32 bit jumps properly.

Despite not being an ARM thumb expert, I do know a 32 bit jump requires loading a register 1st, then jumping to the register, while a 16 bit jump can be done to a literal.



Simply integrating the gyros was how Mikrokopter originally worked & it seemed to be real stable & fast. So the same thing was done on Marcy2 with pretty bad results, on the bench. At least it updates at over 1000hz. Doing the full quaternion rotation would be quite unpleasant & slow. The theory is a fast, inaccurate AHRS would be better for an indoor vehicle than the complete quaternion. This is all because of the lack of time to bring up the full floating point functionality & desire to have something that would work on a simpler micro.



Finally, the bench is made of wood & wifi doesn't work when the antenna is near wood. Not surprisingly, the board can't be used at all when lying on the bench.
Last edited by Jack Crossfire; Feb 26, 2013 at 07:03 AM.
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