// ADC0838.java by JWB, June 1, 2006 // based on ADC0831 and multi3 code // this class could not be found by compilier..so it was redone as ADC_0838 //package stamp.peripheral.io.ADC; import stamp.core.*; import stamp.util.text.Format; public class ADC0838 { // Pin Constants unique to chip private int enablePin; // ADC0838 enable pin #18 private int dataPin; // ADC0838 data pin #14 in, #17 out private int clockPin; // ADC0838 clock pin #16 private int clockIn; private int muxbyte; private int readSize = 9; // #Bits to Read on the ADC0838 private int nBits = 5; // #bits to Send public ADC0838(int dataPin, int clockPin, int enablePin){ // update protected variables this.dataPin = dataPin; this.clockPin = clockPin; this.enablePin = enablePin; //resolution = 256; // Range of the ADC0838 CPU.writePin(enablePin, true); // set ready to trigger with high to low CPU.delay(100); }// end constructor: ADC0838 /** * Read value from A to D chip.

* Multiple channels are available on the ADC0838 * @param channel dummy value for ADC0831 to conform to base class * @return raw value from chip */ public int read(int channel){ CPU.writePin(clockPin, false); // set clockpin low for + pulses //muxbyte = %11000 | ((channel &%001) << 2) | ((channel & %110) >> 1); // %11000 = 24, %001 = 1, %110 = 6 clockIn = 0; muxbyte = 24 | ((channel & 1) << 2) | ((channel & 6) >> 1); Format.printf(" muxbyte=%i",muxbyte); Format.printf(" dataPin=%i",dataPin); Format.printf(" clockPin=%i",clockPin); Format.printf(" enablePin=%i",enablePin); Format.printf(" readSize=%i",readSize); CPU.writePin(enablePin,false); // trigger data xfer CPU.shiftOut(dataPin, clockPin, nBits, CPU.SHIFT_MSB, muxbyte <<11); //CPU.shiftOut(dataPin, clockPin, nBits, CPU.SHIFT_MSB, muxbyte <<8); clockIn = CPU.shiftIn(dataPin,clockPin,readSize,CPU.POST_CLOCK_MSB); CPU.writePin(enablePin,true); //reset for next read clockIn = clockIn & 0x00FF; // clear 9th bit, as per Jon Williams Format.printf(" clockIn=%i",clockIn); //clockIn = clockIn >>8; // data byte must go to RHS after xfer //clockIn = CPU.shiftIn(dataPin,clockPin,readSize,CPU.PRE_CLOCK_MSB); CPU.delay(100); //lastRaw = clockIn; // raw is protected return clockIn; }// end method: read }// end class: ADC0838