first commit

2025-07-22 15:27:00 +02:00
commit 6c6451c92c
205 changed files with 44418 additions and 0 deletions
--- a/RHSoftwareSPI.cpp
+++ b/RHSoftwareSPI.cpp
@@ -0,0 +1,166 @@
+// SoftwareSPI.cpp
+// Author: Chris Lapa (chris@lapa.com.au)
+// Copyright (C) 2014 Chris Lapa
+// Contributed by Chris Lapa
+
+#include <RHSoftwareSPI.h>
+
+RHSoftwareSPI::RHSoftwareSPI(Frequency frequency, BitOrder bitOrder, DataMode dataMode)
+    :
+    RHGenericSPI(frequency, bitOrder, dataMode)
+{
+    setPins(12, 11, 13);
+}
+
+// Caution: on Arduino Uno and many other CPUs, digitalWrite is quite slow, taking about 4us
+// digitalWrite is also slow, taking about 3.5us
+// resulting in very slow SPI bus speeds using this technique, up to about 120us per octet of transfer
+uint8_t RHSoftwareSPI::transfer(uint8_t data) 
+{
+    uint8_t readData;
+    uint8_t writeData;
+    uint8_t builtReturn;
+    uint8_t mask;
+    
+    if (_bitOrder == BitOrderMSBFirst)
+    {
+	mask = 0x80;
+    }
+    else
+    {
+	mask = 0x01;
+    }
+    builtReturn = 0;
+    readData = 0;
+
+    for (uint8_t count=0; count<8; count++)
+    {
+	if (data & mask)
+	{
+	    writeData = HIGH;
+	}
+	else
+	{
+	    writeData = LOW;
+	}
+
+	if (_clockPhase == 1)
+	{
+	    // CPHA=1, miso/mosi changing state now
+	    digitalWrite(_mosi, writeData);
+	    digitalWrite(_sck, ~_clockPolarity);
+	    delayPeriod();
+
+	    // CPHA=1, miso/mosi stable now
+	    readData = digitalRead(_miso);
+	    digitalWrite(_sck, _clockPolarity);
+	    delayPeriod();
+	}
+	else
+	{
+	    // CPHA=0, miso/mosi changing state now
+	    digitalWrite(_mosi, writeData);
+	    digitalWrite(_sck, _clockPolarity);
+	    delayPeriod();
+
+	    // CPHA=0, miso/mosi stable now
+	    readData = digitalRead(_miso);
+	    digitalWrite(_sck, ~_clockPolarity);
+	    delayPeriod();
+	}
+			
+	if (_bitOrder == BitOrderMSBFirst)
+	{
+	    mask >>= 1;
+	    builtReturn |= (readData << (7 - count));
+	}
+	else
+	{
+	    mask <<= 1;
+	    builtReturn |= (readData << count);
+	}
+    }
+
+    digitalWrite(_sck, _clockPolarity);
+
+    return builtReturn;
+}
+
+/// Initialise the SPI library
+void RHSoftwareSPI::begin()
+{
+    if (_dataMode == DataMode0 ||
+	_dataMode == DataMode1)
+    {
+	_clockPolarity = LOW;
+    }
+    else
+    {
+	_clockPolarity = HIGH;
+    }
+		
+    if (_dataMode == DataMode0 ||
+	_dataMode == DataMode2)
+    {
+	_clockPhase = 0;
+    }
+    else
+    {
+	_clockPhase = 1;
+    }
+    digitalWrite(_sck, _clockPolarity);
+
+    // Caution: these counts assume that digitalWrite is very fast, which is usually not true
+    switch (_frequency)
+    {
+	case Frequency1MHz:
+	    _delayCounts = 8;
+	    break;
+
+	case Frequency2MHz:
+	    _delayCounts = 4;
+	    break;
+
+	case Frequency4MHz:
+	    _delayCounts = 2;
+	    break;
+
+	case Frequency8MHz:
+	    _delayCounts = 1;
+	    break;
+
+	case Frequency16MHz:
+	    _delayCounts = 0;
+	    break;
+    }
+}
+
+/// Disables the SPI bus usually, in this case
+/// there is no hardware controller to disable.
+void RHSoftwareSPI::end() { }
+
+/// Sets the pins used by this SoftwareSPIClass instance.
+/// \param[in] miso master in slave out pin used
+/// \param[in] mosi master out slave in pin used
+/// \param[in] sck clock pin used
+void RHSoftwareSPI::setPins(uint8_t miso, uint8_t mosi, uint8_t sck)
+{
+    _miso = miso;
+    _mosi = mosi;
+    _sck = sck;
+
+    pinMode(_miso, INPUT);
+    pinMode(_mosi, OUTPUT);
+    pinMode(_sck, OUTPUT);
+    digitalWrite(_sck, _clockPolarity);
+}
+
+
+void RHSoftwareSPI::delayPeriod()
+{
+    for (uint8_t count = 0; count < _delayCounts; count++)
+    {
+	__asm__ __volatile__ ("nop");
+    }
+}
+