On 2013-12-22 04:25, Charles Steinkuehler wrote: > On 12/21/2013 6:40 PM, Bas de Bruijn wrote: >> Hi There, >> >> I try to run LinuxCNC on the BeagleBone Black, with a BeBoPr+ >> (bridge) board which I acquired via Bas Laarhoven and arrived >> yesterday. Goal is to run LinuxCNC with my delta printer. >> >> I have a strange behaviour though. The temperature readings bars in >> axis which show the temperature from Extruder and Heated bed swing >> wildly. > > Exactly what does "swing wildly" mean? There is quite a bit of noise > when using the on-chip A/D converter on the BeagleBone, but for me it > works out to around one degree Centigrade or so of noise.
the values in the temperature bars of Axis range from -7 to 30 changing very rapidly. > If you're > seeing significantly more than that, check your wiring. Make sure > all > connections are solid, route the thermistor wires (which should be > twisted to reduce noise pickup) away from the heater and motor wires, > etc. I have connected 2 thermistors with short prototype wires. approx 5 cm lomg. I have not yet added motors and stepper driver boards, nor heater. Basically just to test the board and get comfortable with them and LinuxCNC. Removing the thermistor(s) does not make a difference in varying ADC values, and I expected to see that the value would go to minus something, indicating it's not connected. Maybe some clash regarding mapping of ADC pins? I'll take a closer look at that. (any nudge if I'm taking the wrong approach will be appreciated) > Alternately, you could use the TI ADC that Bas has provisions for on > the > BeBoPr (see his github wiki for details). I haven't tried this > myself, > but I have the kernel modules available and it is reported to work > quit > well. I'll have a look at that, I'm comfortable with electronics and some programming. Although I'm not an expert. Talking about kernel modules gives me goosebumps and sets my knees to rattle :) There's a first thing for everything. ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
