126 lines
3.9 KiB
C++
126 lines
3.9 KiB
C++
#ifndef ADS7818_h
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#define ADS7871_h
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//------------------------------------------------------------------------------
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/** nop to tune soft SPI timing */
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#define nop asm volatile ("nop\n\t")
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//------------------------------------------------------------------------------
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/** doxygen can't handle __attribute__ very well */
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#define STATIC_ALWAYS_INLINE static inline __attribute__((always_inline))
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//------------------------------------------------------------------------------
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template<uint8_t ClkPin, uint8_t ConvPin, uint8_t DataPin>
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/** ADS7818 class */
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class ADS7818 {
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public:
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//----------------------------------------------------------------------------
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/** Set pin modes and initial levels. */
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void begin() {
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fastPinMode(ClkPin, 1);
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fastDigitalWrite(ClkPin, 0);
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fastPinMode(ConvPin, 1);
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fastDigitalWrite(ConvPin, 1);
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fastPinMode(DataPin, 0);
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}
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//----------------------------------------------------------------------------
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/** Read ADS7818 12-bit ADC
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* \return 16-bit value read.
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*/
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inline __attribute__((always_inline))
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uint16_t read() {
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uint16_t v = 0;
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fastDigitalWrite(ConvPin, 0);
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fastDigitalWrite(ClkPin, 1);
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fastDigitalWrite(ClkPin, 0);
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fastDigitalWrite(ConvPin, 1);
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fastDigitalWrite(ClkPin, 1);
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fastDigitalWrite(ClkPin, 0);
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readBitFast16(v, 11);
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readBitFast16(v, 10);
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readBitFast16(v, 9);
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readBitFast16(v, 8);
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readBitFast16(v, 7);
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readBitFast16(v, 6);
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readBitFast16(v, 5);
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readBitFast16(v, 4);
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readBitFast16(v, 3);
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readBitFast16(v, 2);
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readBitFast16(v, 1);
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readBitFast16(v, 0);
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return v;
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}
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private:
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//----------------------------------------------------------------------------
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inline __attribute__((always_inline))
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void readBitFast16(uint16_t &v, uint8_t b) {
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fastDigitalWrite(ClkPin, 1);
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if (fastDigitalRead(DataPin)) v |= (1 << b);
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fastDigitalWrite(ClkPin, 0);
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}
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};
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#if 0
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/** initialize I/O ports */
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STATIC_ALWAYS_INLINE void adcBegin() {
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fastPinMode(ADC_CLK_PIN, 1);
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fastDigitalWrite(ADC_CLK_PIN, 0);
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fastPinMode(ADC_CONV_PIN, 1);
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fastDigitalWrite(ADC_CONV_PIN, 1);
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fastPinMode(ADC_DATA_PIN, 0);
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}
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//------------------------------------------------------------------------------
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/** clock for don't care bits
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*\param[in] delayBefore if true, delay before raising clock*/
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STATIC_ALWAYS_INLINE void fastDummy(bool first) {
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if (!first) nop;
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fastDigitalWrite(ADC_CLK_PIN, 1);
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nop;
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fastDigitalWrite(ADC_CLK_PIN, 0);
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}
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//------------------------------------------------------------------------------
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/** read next bit fast as possible
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* \param[in] v word to receive bit
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* \param[in] b bit number to be set. v |= (1 << b) if next bit is high.
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*/
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STATIC_ALWAYS_INLINE void readBitFast16(uint16_t &v, uint8_t b) {
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fastDigitalWrite(ADC_CLK_PIN, 1);
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if (fastDigitalRead(ADC_DATA_PIN)) v |= (1 << b);
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fastDigitalWrite(ADC_CLK_PIN, 0);
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}
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//------------------------------------------------------------------------------
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/** Read AD7680 16-bit ADC in less than 8 microseconds
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* cs is chip select pin
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*/
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STATIC_ALWAYS_INLINE uint16_t adcRead(bool centered = false) {
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uint16_t v = 0;
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fastDigitalWrite(ADC_CONV_PIN, 0);
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fastDigitalWrite(ADC_CLK_PIN, 1);
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fastDigitalWrite(ADC_CLK_PIN, 0);
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fastDigitalWrite(ADC_CONV_PIN, 1);
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fastDigitalWrite(ADC_CLK_PIN, 1);
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fastDigitalWrite(ADC_CLK_PIN, 0);
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// uint16_t v = 0;
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// fastDummy(1);
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// fastDummy(0);
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// fastDummy(0);
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// fastDummy(0);
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// readBitFast16(v, 15);
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// readBitFast16(v, 14);
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// readBitFast16(v, 13);
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// readBitFast16(v, 12);
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readBitFast16(v, 11);
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readBitFast16(v, 10);
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readBitFast16(v, 9);
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readBitFast16(v, 8);
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readBitFast16(v, 7);
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readBitFast16(v, 6);
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readBitFast16(v, 5);
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readBitFast16(v, 4);
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readBitFast16(v, 3);
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readBitFast16(v, 2);
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readBitFast16(v, 1);
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readBitFast16(v, 0);
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return centered ? v ^ 0X8000 : v;
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}
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#endif // 0
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#endif // ADS7818_h
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