mirror of https://github.com/ArduPilot/ardupilot
79 lines
1.4 KiB
C
79 lines
1.4 KiB
C
/*
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ADS7844 register emulation
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Code by Andrew Tridgell November 2011
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*/
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#ifndef _SITL_ADC_H
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#define _SITL_ADC_H
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#include <stdlib.h>
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#include <math.h>
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#include "util.h"
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// this implements the UDR2 register
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struct ADC_UDR2 {
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uint16_t value, next_value;
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uint8_t idx;
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float channels[8];
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ADC_UDR2() {
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// constructor
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for (uint8_t i=0; i<8; i++) {
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channels[i] = 0xFFFF;
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}
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value = next_value = 0;
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idx = 0;
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}
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/*
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assignment of UDR2 selects which ADC channel
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to output next
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*/
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ADC_UDR2& operator=(uint8_t cmd) {
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float next_analog;
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uint8_t chan;
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switch (cmd) {
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case 0x87: chan = 0; break;
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case 0xC7: chan = 1; break;
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case 0x97: chan = 2; break;
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case 0xD7: chan = 3; break;
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case 0xA7: chan = 4; break;
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case 0xE7: chan = 5; break;
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case 0xB7: chan = 6; break;
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case 0xF7: chan = 7; break;
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case 0:
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default: return *this;
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}
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next_analog = channels[chan];
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idx = 1;
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if (next_analog > 0xFFF) next_analog = 0xFFF;
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if (next_analog < 0) next_analog = 0;
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next_value = ((unsigned)next_analog) << 3;
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return *this;
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}
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/*
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read from UDR2 fetches a byte from the channel
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*/
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operator int() {
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uint8_t ret;
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if (idx & 1) {
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ret = (value&0xFF);
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value = next_value;
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} else {
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ret = (value>>8);
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}
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idx ^= 1;
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return ret;
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}
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/*
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interface to set a channel value from SITL
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*/
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void set(uint8_t i, float v) {
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channels[i] = v;
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}
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};
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#endif // _SITL_ADC_H
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