The Furaday cape says it has 5v PWM outputs on P1.... https://docs.google.com/spreadsheets/d/1D2rlEZcO0M6Qlk-UZ7ufp3wbE0IHuzRvnHuqvfVDcJY/edit#gid=1554435935
Maybe you're using a field output as PWM? If you can't get around that these are cheap and worth a try..... https://www.amazon.com/24V-Optocoupler-Voltage-Level-Converter/dp/B01EY767S8?th=1 You can feed the 24v PWM into the input and it will output an inverted 5v PWM. I don't have a BBB but looking at hal_pru the pwmgen component has a scale pin and it looks like a value of -1 will invert the PWM and cancel the boards inversion out if it matters which it probably doesn't. You can just use an optocoupler output on that cape to pull the F/R pin to speed_gnd on the driver board to change directions. The cape handles 0-5v analog outputs as well so you could use that too. The KB drive is just a PIA at that point. You can use the serial thing but I'm not sure what difference you think it makes. The only thing that serial can do is command a speed output to the driver board. You still have to close the loop with feedback coming from something else, like an encoder which doesn't change regardless of whether you use PWM/serial/or analog. If you command a speed of 300rpms No matter which you choose all it can do is command an output that you tune to be as close to relate to 300RPM as you can. So if you go to take a cut and the spindle bogs down there is no way to detect that unless you have an encoder and run a PID loop. The PID will compensate for the slowdown by increasing or decreasing the output command to hold steady, it could be a serial command to speed up, a PWM duty cycle increase, or an analog voltage increase, it doesn't matter if the PID is setup right. Analog is a bit more susceptible to noise than PWM. Serial is fine if you really want to deal with it but I'm not sure I see why you would. It looks like if you configure the outputs on your BBB/cape right all really don't need anything extra. On Monday, July 15, 2019 at 9:31:48 PM UTC-4, Aurelien wrote: > > Yes i have found this controler firstly by schearching something with PWM > input and possible reverse. > > My problem with the ebay controler is to convert my furaday 0/24v PWM to > 0/5v PWM isolated, unfortunatly i'm not able to design something like this > myself. > The seller send to me only the 3 first attached documents after waiting > and ask again and again from 4 month. > (edit : i have think about keep the k24p-10v with the ebay controler and > use the reverse function the easy way) > > The KBMG is retrofited when start the project, in reality i like to keep > this controler if i can found for reversing (maybee find someone and pay > some money for a ready to use solution for this one or for the PWM ebay) > > For the suggestion about retrofit AC motor it's i think for a lathe with > motor integrated to the spindle this not the best way. > > Many thanks for your interest > > > Ps : Finally you think it is better for spindle accuracy to have a simple > PWM (or PWM/analog) with pru or a complex C code comp file with serial > communication or this is only more easy to use PWM ? (I'm lost : finalize > the order or not lol) > -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. To view this discussion on the web visit https://groups.google.com/d/msgid/machinekit/e7259d91-14b5-449d-8331-42da6cf33279%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
