![](/media/cache/img/default_profile.jpg.50x50_q85.jpg)
work in progress
Dependencies: FastAnalogIn FastIO USBDevice mbed FastPWM SimpleDMA
Fork of Pinscape_Controller by
Diff: main.cpp
- Revision:
- 23:14f8c5004cd0
- Parent:
- 22:71422c359f2a
- Child:
- 25:e22b88bd783a
--- a/main.cpp Wed Apr 01 22:57:31 2015 +0000 +++ b/main.cpp Wed Jun 03 18:50:34 2015 +0000 @@ -1489,7 +1489,7 @@ // // Note that negative values are allowed. Zero represents the // "park" position, where the plunger sits when at rest. A mechanical - // plunger has a smmall amount of travel in the "push" direction, + // plunger has a small amount of travel in the "push" direction, // since the barrel spring can be compressed slightly. Negative // values represent travel in the push direction. if (pos > cfg.d.plungerMax) @@ -1511,25 +1511,44 @@ // The plunger has moved forward since the previous report. // Watch it for a few more ms to see if we can get a stable // new position. - int pos1 = plungerSensor.lowResScan(); + int pos0 = plungerSensor.lowResScan(); + int pos1 = pos0; Timer tw; tw.start(); while (tw.read_ms() < 6) { - // if we've crossed the rest position, it's a firing event - if (pos1 < cfg.d.plungerZero) + // read the new position + int pos2 = plungerSensor.lowResScan(); + + // If it's stable over consecutive readings, stop looping. + // (Count it as stable if the position is within about 1/8". + // pos1 and pos2 are reported in pixels, so they range from + // 0 to npix. The overall travel of a standard plunger is + // about 3.2", so we have (npix/3.2) pixels per inch, hence + // 1/8" is (npix/3.2)*(1/8) pixels.) + if (abs(pos2 - pos1) < int(npix/(3.2*8))) + break; + + // If we've crossed the rest position, and we've moved by + // a minimum distance from where we starting this loop, begin + // a firing event. (We require a minimum distance to prevent + // spurious firing from random analog noise in the readings + // when the plunger is actually just sitting still at the + // rest position. If it's at rest, it's normal to see small + // random fluctuations in the analog reading +/- 1% or so + // from the 0 point, especially with a sensor like a + // potentionemeter that reports the position as a single + // analog voltage.) Note that we compare the latest reading + // to the first reading of the loop - we don't require the + // threshold motion over consecutive readings, but any time + // over the stability wait loop. + if (pos1 < cfg.d.plungerZero + && abs(pos2 - pos0) > int(npix/(3.2*8))) { firing = 1; break; } - - // read the new position - int pos2 = plungerSensor.lowResScan(); - - // if it's stable, stop looping - if (abs(pos2 - pos1) < int(npix/(3.2*8))) - break; - + // the new reading is now the prior reading pos1 = pos2; }