Greetings all; Some confusion about useing the mesa pwmgens in a 5i25 with the 5i25_7i76_1px2d.bit file loaded. this bitfile fails to wire up the dir output, but is as close to driveing a stock bob on p2 as there is.
In order to use both pwmgens, I have added and ABS module for each pwmgen, feeding it the pwmgen.xx.value, and using the sign bit output in place of the missing pwmgen.01 mode=1 DIR line. But because I needed both polarities to control the H-bridge, something I can get out of pwmgen.00, I've swapped the spindle duties to pwmgen.01 which only needs one dir signal, and put the A axis on pwmgen.00 where I can get the complimentary DIRs out of TB3 on the 7i76D. It almost works. I can run the spindle either direction but it runs it slightly rough because the pwm output is in groups of pulses, making perhaps 20 pulses, then stopping for a few milliseconds, then making another group of pulses. Looking at the encoder output with a real scope, the speed variation is nearly 50% while averaging the requested 100 revs. I thought my encoder was going out but its still tightly coupled to the motor shaft, so there isn't any slippage unless its internal, and I have about made up my mind to obtain another encoder. Until I started up wireing up that car seat H-bridge from olymex to drive the A axis as a servo. That motors encoder is wired up in hal, but is not yet connected to the bobs inputs 1,2,3 for encoder.01's IDX,encA,encB. The IDX will be a switch on the BS-1, used for a home switch, not wired up yet because the motor is yt to be mounte. So there is not any A feedback. For testing, pid.A.FF0 is 1, the remaining pid inputs are all zero'd. So theoreticly pid.A.output is straight thru from the [] keys. The cobbled up abs.A.sign works, giving a plus DIR signal to which ever side of the top half of H-bridge you want the motor to run, while the bottom half is pulsed by the pwm. And it switches the stepgen#3 outputs at exactly 0.00000 at the pwmgen.00.value just like I expected. But the pulses from that pwmgen.00 are coming out in groups, then silence, basicly acting quite like the other pwmgen.01 now driving the spindle rather noisily. I'm stumped. The DC supplies running the cards are solid at 5.1 and 12.05 for field power. Has anyone a clue what I might be fighting with? The FUNCTION's shown in the man page I assume do not exist for the mesa versions, so there are no addf lines for them. Should there be? There are these addf's first: addf hm2_5i25.0.read_gpio servo-thread addf hm2_5i25.0.read servo-thread couple more pages of addf's # and finally, update machine addf hm2_5i25.0.write_gpio servo-thread addf hm2_5i25.0.write servo-thread I do note that hm2_5i25.0.dpll.phase-error-us is dancing wildly, over about a +-50 range, much wilder than the other 2 machines that have that pin in the halmeter menu. They are only showing a +-1 or 2 dance. Thanks all. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
