Henrik Ekblad
2fd948fc66
Upgraded RF24 to latest version which supports SoftSPI. Added DigitalIO and UTFT libraries to support the new example. Fix problem reported in RelayWithButtonActuator example.
126 lines
3.9 KiB
C++
126 lines
3.9 KiB
C++
#ifndef MCP355X_h
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#define MCP355X_h
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#include <DigitalIO.h>
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// Overflow values.
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const int32_t MCP355X_OVH = 2097152L;
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const int32_t MCP355X_OVL = -2097153L;
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const int32_t MCP355X_ERR = 0X80000000;
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const uint8_t MCP355X_TO_MS = 100;
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//==============================================================================
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template<uint8_t CsPin, uint8_t SckPin, uint8_t SdoPin>
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class MCP355X {
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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(bool singleMode = true) {
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m_singleMode = singleMode;
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fastPinMode(SdoPin, 0);
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fastPinMode(SckPin, 1);
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fastDigitalWrite(SckPin, 1);
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fastPinMode(CsPin, 1);
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fastDigitalWrite(CsPin, 1);
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if (!m_singleMode) {
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// Wait for conversion to complete.
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delay(100);
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// Start continuous conversion mode.
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fastDigitalWrite(CsPin, 0);
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}
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}
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//----------------------------------------------------------------------------
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/** Read MCP355X 22-bit ADC
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* \return 22-bit value.
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*/
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inline __attribute__((always_inline))
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int32_t read() {
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uint8_t t = 0;
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uint8_t v3 = 0;
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if (m_singleMode) {
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// Start conversion.
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fastDigitalWrite(CsPin, 0);
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// Delay at least 10 usec to avoid RDY glitch on exit from Shutdown.
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delay(1);
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// Toggle CsPin to indicate single conversion mode.
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fastDigitalWrite(CsPin, 1);
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// Wait for conversion to complete.
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while (1) {
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delay(1);
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fastDigitalWrite(CsPin, 0);
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// Delay while RDY settles.
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delayCycles(4);
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if (!fastDigitalRead(SdoPin)) break;
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fastDigitalWrite(CsPin, 1);
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if (t++ > MCP355X_TO_MS) return MCP355X_ERR;
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}
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} else {
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while (1) {
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if (!fastDigitalRead(SdoPin)) break;
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delay(1);
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if (t++ > MCP355X_TO_MS) return MCP355X_ERR;
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}
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}
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uint8_t v2 = readByte();
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uint8_t v1 = readByte();
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uint8_t v0 = readByte();
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// The 25th falling edge of SCK changes SDO/RDY from Data mode to RDY mode.
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uint8_t dummy = 0;
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readBit(dummy, 0);
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if (m_singleMode) {
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fastDigitalWrite(CsPin, 1);
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}
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if ((v2 & 0XE0) == 0X20) {
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// Negative in range so extend sign bit.
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v2 |= 0XC0;
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v3 = 0XFF;
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} else if (v2 & 0X40) {
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// Overflow high. Cause value to be >= MCP355X_OVH.
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if (v2 & 0X20) v2 &= 0X3F;
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} else if (v2 & 0X80) {
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// Overflow low. Cause value to be <= MCP355X_OVH.
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if ((v2 & 0X20) == 0) v2 |= 0X40;
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v3 = 0XFF;
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}
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uint16_t v_high = (v3 << 8) | v2;
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uint16_t v_low = (v1 << 8) | v0;
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return ((uint32_t)v_high << 16) | v_low;
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}
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private:
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//----------------------------------------------------------------------------
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/** delay n nops
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* \param[in] n nops to delay, must be a constant so compiler optimizes if().
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*/
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inline __attribute__((always_inline))
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void delayCycles(uint8_t n) {
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if (n & 1) asm volatile("nop\n\t");
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if (n & 2) asm volatile("nop\n\t" "nop\n\t");
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if (n & 4) asm volatile("nop\n\t" "nop\n\t" "nop\n\t" "nop\n\t");
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}
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//----------------------------------------------------------------------------
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// Default delay yields about 2 MHz clock.
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inline __attribute__((always_inline))
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void readBit(uint8_t &v, uint8_t b, uint8_t delayRead = 0) {
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fastDigitalWrite(SckPin, 0);
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delayCycles(2 + delayRead);
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fastDigitalWrite(SckPin, 1);
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if (fastDigitalRead(SdoPin)) v |= (1 << b);
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delayCycles(delayRead);
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}
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//----------------------------------------------------------------------------
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inline __attribute__((always_inline))
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uint8_t readByte() {
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uint8_t v = 0;
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readBit(v, 7);
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readBit(v, 6);
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readBit(v, 5);
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readBit(v, 4);
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readBit(v, 3);
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readBit(v, 2);
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readBit(v, 1);
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readBit(v, 0);
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return v;
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}
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//----------------------------------------------------------------------------
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bool m_singleMode;
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};
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#endif // MCP355X_h
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