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esp32_Adafruit_BusIO
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only write MOSI if its changed

This commit is contained in:
lady ada 2020-07-18 15:57:15 -04:00
parent a830055740
commit a552fae34e
1 changed files with 7 additions and 3 deletions
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10
Adafruit_SPIDevice.cpp
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@ -123,6 +123,8 @@ void Adafruit_SPIDevice::transfer(uint8_t *buffer, size_t len) {
startbit = 0x80; startbit = 0x80;
} }
bool towrite, lastmosi = ! (buffer[0] & startbit);
// for softSPI we'll do it by hand // for softSPI we'll do it by hand
for (size_t i = 0; i < len; i++) { for (size_t i = 0; i < len; i++) {
// software SPI // software SPI
@ -138,15 +140,17 @@ void Adafruit_SPIDevice::transfer(uint8_t *buffer, size_t len) {
// Serial.print(send, HEX); // Serial.print(send, HEX);
for (uint8_t b = startbit; b != 0; b = (_dataOrder == SPI_BITORDER_LSBFIRST) ? b << 1 : b >> 1) { for (uint8_t b = startbit; b != 0; b = (_dataOrder == SPI_BITORDER_LSBFIRST) ? b << 1 : b >> 1) {
if (_dataMode == SPI_MODE0 || _dataMode == SPI_MODE2) { if (_dataMode == SPI_MODE0 || _dataMode == SPI_MODE2) {
if (_mosi != -1) { towrite = send & b;
if ((_mosi != -1) && (lastmosi != towrite)) {
#ifdef BUSIO_USE_FAST_PINIO #ifdef BUSIO_USE_FAST_PINIO
if (send & b) if (towrite)
*mosiPort |= mosiPinMask; *mosiPort |= mosiPinMask;
else else
*mosiPort &= ~mosiPinMask; *mosiPort &= ~mosiPinMask;
#else #else
digitalWrite(_mosi, send & b); digitalWrite(_mosi, towrite);
#endif #endif
lastmosi = towrite;
} }
#ifdef BUSIO_USE_FAST_PINIO #ifdef BUSIO_USE_FAST_PINIO