Mike R / Mbed 2 deprecated Pinscape_Controller_V2

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Dependencies:   mbed FastIO FastPWM USBDevice

Fork of Pinscape_Controller by Mike R

plunger.h@43:7a6364d82a41, 2016-02-06 (annotated)

Committer:
mjr
Date:
Sat Feb 06 20:21:48 2016 +0000
Revision:
43:7a6364d82a41
Parent:
35:e959ffba78fd
Child:
44:b5ac89b9cd5d
Before floating point plunger ranging

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mjr 35:e959ffba78fd 1 // Plunger Sensor Interface
mjr 35:e959ffba78fd 2 //
mjr 35:e959ffba78fd 3 // This module defines the abstract interface to the plunger sensors.
mjr 35:e959ffba78fd 4 // We support several different physical sensor types, so we need a
mjr 35:e959ffba78fd 5 // common interface for use in the main code.
mjr 35:e959ffba78fd 6 //
mjr 35:e959ffba78fd 7
mjr 35:e959ffba78fd 8 #ifndef PLUNGER_H
mjr 35:e959ffba78fd 9 #define PLUNGER_H
mjr 35:e959ffba78fd 10
mjr 35:e959ffba78fd 11 class PlungerSensor
mjr 35:e959ffba78fd 12 {
mjr 35:e959ffba78fd 13 public:
mjr 35:e959ffba78fd 14
mjr 35:e959ffba78fd 15 PlungerSensor() { }
mjr 35:e959ffba78fd 16 virtual ~PlungerSensor() { }
mjr 35:e959ffba78fd 17
mjr 35:e959ffba78fd 18 // Number of "pixels" in the sensor's range. We use the term "pixels"
mjr 35:e959ffba78fd 19 // here for historical reasons, namely that the first sensor we implemented
mjr 35:e959ffba78fd 20 // was an imaging sensor that physically sensed the plunger position as
mjr 35:e959ffba78fd 21 // a pixel coordinate in the image. But it's no longer the right word,
mjr 35:e959ffba78fd 22 // since we support sensor types that have nothing to do with imaging.
mjr 35:e959ffba78fd 23 // Even so, the function this serves is still applicable. Abstractly,
mjr 43:7a6364d82a41 24 // it represents the physical resolution of the sensor in terms of
mjr 43:7a6364d82a41 25 // the number of quanta over the full range of travel of the plunger.
mjr 43:7a6364d82a41 26 // For sensors that inherently quantize the position reading at the
mjr 43:7a6364d82a41 27 // physical level, such as imaging sensors and quadrature sensors,
mjr 43:7a6364d82a41 28 // this should be set to the total number of position steps over the
mjr 43:7a6364d82a41 29 // range of travel. For devices with physically analog outputs, such
mjr 43:7a6364d82a41 30 // as potentiometers or LVDTs, the reading still has to be digitized
mjr 43:7a6364d82a41 31 // for us to be able to work with it, which means it has to be turned
mjr 43:7a6364d82a41 32 // into a value that's fundamentally an integer. But this happens in
mjr 43:7a6364d82a41 33 // the ADC, so the quantization scale is hidden in the mbed libraries.
mjr 43:7a6364d82a41 34 // The normal KL25Z ADC configuration is 16-bit quantization, so the
mjr 43:7a6364d82a41 35 // quantization factor is usually 65535. But you might prefer to set
mjr 43:7a6364d82a41 36 // this to the joystick maximum so that there are no more rounding
mjr 43:7a6364d82a41 37 // errors in scale conversions after the point of initial conversion.
mjr 35:e959ffba78fd 38 //
mjr 43:7a6364d82a41 39 // IMPORTANT! This value MUST be initialized in the constructor for
mjr 43:7a6364d82a41 40 // each concrete subclass.
mjr 35:e959ffba78fd 41 int npix;
mjr 35:e959ffba78fd 42
mjr 35:e959ffba78fd 43 // Initialize the physical sensor device. This is called at startup
mjr 35:e959ffba78fd 44 // to set up the device for first use.
mjr 35:e959ffba78fd 45 virtual void init() = 0;
mjr 35:e959ffba78fd 46
mjr 35:e959ffba78fd 47 // Take a high-resolution reading. Sets pos to the current position,
mjr 35:e959ffba78fd 48 // on a scale from 0 to npix: 0 is the maximum forward plunger position,
mjr 35:e959ffba78fd 49 // and npix is the maximum retracted position, in terms of the sensor's
mjr 35:e959ffba78fd 50 // extremes. This is a raw reading in terms of the sensor range; the
mjr 35:e959ffba78fd 51 // caller is responsible for applying calibration data and scaling the
mjr 35:e959ffba78fd 52 // result to the the joystick report range.
mjr 35:e959ffba78fd 53 //
mjr 35:e959ffba78fd 54 // Returns true on success, false on failure. Return false if it wasn't
mjr 35:e959ffba78fd 55 // possible to take a good reading for any reason.
mjr 35:e959ffba78fd 56 virtual bool highResScan(int &pos) = 0;
mjr 35:e959ffba78fd 57
mjr 35:e959ffba78fd 58 // Take a low-resolution reading. This reports the result on the same
mjr 35:e959ffba78fd 59 // 0..npix scale as highResScan(). Returns true on success, false on
mjr 35:e959ffba78fd 60 // failure.
mjr 35:e959ffba78fd 61 //
mjr 35:e959ffba78fd 62 // The difference between the high-res and low-res scans is the amount
mjr 35:e959ffba78fd 63 // of time it takes to complete the reading. The high-res scan is allowed
mjr 35:e959ffba78fd 64 // to take about 10ms; a low-res scan take less than 1ms. For many
mjr 35:e959ffba78fd 65 // sensors, either of these time scales would yield identical resolution;
mjr 35:e959ffba78fd 66 // if that's the case, simply take a reading the same way in both functions.
mjr 35:e959ffba78fd 67 // The distinction is for the benefit of sensors that need significantly
mjr 35:e959ffba78fd 68 // longer to read at higher resolutions, such as image sensors that have
mjr 35:e959ffba78fd 69 // to sample pixels serially.
mjr 35:e959ffba78fd 70 virtual bool lowResScan(int &pos) = 0;
mjr 35:e959ffba78fd 71
mjr 35:e959ffba78fd 72 // Send an exposure report to the joystick interface. This is specifically
mjr 35:e959ffba78fd 73 // for image sensors, and should be omitted by other sensor types. For
mjr 35:e959ffba78fd 74 // image sensors, this takes one exposure and sends all pixels to the host
mjr 35:e959ffba78fd 75 // through special joystick reports. This is used for PC-side testing tools
mjr 35:e959ffba78fd 76 // to let the user check the sensor installation by directly viewing its
mjr 35:e959ffba78fd 77 // pixel output.
mjr 35:e959ffba78fd 78 virtual void sendExposureReport(class USBJoystick &js) { }
mjr 35:e959ffba78fd 79 };
mjr 35:e959ffba78fd 80
mjr 35:e959ffba78fd 81 #endif /* PLUNGER_H */