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SPI Updates #13

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SPI Updates #13

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8dc8806
SPI Updates
JSchaenzle Oct 8, 2018
d54f594
Removed enum that ended up being unneeded
JSchaenzle Oct 9, 2018
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16 changes: 10 additions & 6 deletions Adafruit_SSD1306.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -128,21 +128,24 @@ Adafruit_SSD1306::Adafruit_SSD1306(int8_t SID, int8_t SCLK, int8_t DC, int8_t RS
sclk = SCLK;
sid = SID;
hwSPI = false;
spiClass = NULL;
}

// constructor for hardware SPI - we indicate DataCommand, ChipSelect, Reset
Adafruit_SSD1306::Adafruit_SSD1306(int8_t DC, int8_t RST, int8_t CS) : Adafruit_GFX(SSD1306_LCDWIDTH, SSD1306_LCDHEIGHT) {
Adafruit_SSD1306::Adafruit_SSD1306(int8_t DC, int8_t RST, int8_t CS, bool USE_SPI1) : Adafruit_GFX(SSD1306_LCDWIDTH, SSD1306_LCDHEIGHT) {
dc = DC;
rst = RST;
cs = CS;
hwSPI = true;
spiClass = USE_SPI1 ? &SPI1 : &SPI;
}

// initializer for I2C - we only indicate the reset pin!
Adafruit_SSD1306::Adafruit_SSD1306(int8_t reset) :
Adafruit_GFX(SSD1306_LCDWIDTH, SSD1306_LCDHEIGHT) {
sclk = dc = cs = sid = -1;
rst = reset;
spiClass = NULL;
}


Expand All @@ -161,10 +164,11 @@ void Adafruit_SSD1306::begin(uint8_t vccstate, uint8_t i2caddr) {
}
if (hwSPI){
digitalWrite(cs, HIGH);
SPI.setBitOrder(MSBFIRST);
SPI.setClockDivider(SPI_CLOCK_DIV8); // 72MHz / 8 = 9Mhz
SPI.setDataMode(0);
SPI.begin();
spiClass->setBitOrder(MSBFIRST);
spiClass->setClockDivider(SPI_CLOCK_DIV8); // 72MHz / 8 = 9Mhz
spiClass->setDataMode(0);
spiClass->begin(cs); // Passing the chip-select here just sets the pin mode.
// The peripheral won't automatically assert/deassert the pin during operation.
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By not passing the chip select pin here, we were mistakenly allowing the SPI driver to set up the default chip select pin, A2, as an output in addition to the pin that was passed in by the user.

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See https://docs.particle.io/reference/firmware/photon/#begin--3 for details

}
}
else
Expand Down Expand Up @@ -450,7 +454,7 @@ void Adafruit_SSD1306::clearDisplay(void) {
inline void Adafruit_SSD1306::fastSPIwrite(uint8_t d) {

if(hwSPI) {
(void)SPI.transfer(d);
(void)spiClass->transfer(d);
} else {
shiftOut(sid, sclk, MSBFIRST, d); // SSD1306 specs show MSB out first
}
Expand Down
9 changes: 8 additions & 1 deletion Adafruit_SSD1306.h
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Expand Up @@ -111,8 +111,14 @@ All text above, and the splash screen must be included in any redistribution

class Adafruit_SSD1306 : public Adafruit_GFX {
public:

enum SpiPeripheral {
PERIPH_SPI,
PERIPH_SPI1,
};

Adafruit_SSD1306(int8_t SID, int8_t SCLK, int8_t DC, int8_t RST, int8_t CS);
Adafruit_SSD1306(int8_t DC, int8_t RST, int8_t CS);
Adafruit_SSD1306(int8_t DC, int8_t RST, int8_t CS, bool USE_SPI1 = false);
Adafruit_SSD1306(int8_t RST);

void begin(uint8_t switchvcc = SSD1306_SWITCHCAPVCC, uint8_t i2caddr = SSD1306_I2C_ADDRESS);
Expand All @@ -139,6 +145,7 @@ class Adafruit_SSD1306 : public Adafruit_GFX {

private:
int8_t _i2caddr, _vccstate, sid, sclk, dc, rst, cs;
SPIClass * spiClass;
void fastSPIwrite(uint8_t c);

boolean hwSPI;
Expand Down