Added SPI burst mode to spi 8 bit.

Dependents:   Bicycl_Computer_NUCLEO-F411RE Bicycl_Computer_NUCLEO-L476RG

Fork of UniGraphic by GraphicsDisplay

Added SPI burst mode to this graphics driver. If whoever wants this rolled in to repository let me know. I replaced _spi.write(); with fastWrite(); and clearRX();

SPI8.cpp

// need to re-create SPI firmware to access SPI handle
static SPI_HandleTypeDef SpiHandle;

void SPI8::fastWrite(int data) {
    
      SpiHandle.Instance = SPI1;
    // Check if data is transmitted
    while ((SpiHandle.Instance->SR & SPI_SR_TXE) == 0);
    SpiHandle.Instance->DR = data;
}
    
void SPI8::clearRX( void ) {
        SpiHandle.Instance = SPI1;
    //Check if the RX buffer is busy
    //While busy, keep checking
    while (SpiHandle.Instance->SR & SPI_SR_BSY){   
        // Check RX buffer readable
        while ((SpiHandle.Instance->SR & SPI_SR_RXNE) == 0);
        int dummy = SpiHandle.Instance->DR;
    }
}      
Revision:
11:b842b8e332cb
Parent:
7:bb0383b91104
Child:
20:14daa48ffd4c
--- a/Protocols/PAR16.cpp	Thu Feb 19 00:33:27 2015 +0000
+++ b/Protocols/PAR16.cpp	Fri Feb 20 21:32:25 2015 +0000
@@ -150,12 +150,12 @@
     _CS = 1;
 #endif
 }
-unsigned short PAR16::rd_gram()
+unsigned short PAR16::rd_gram(bool convert)
 {
 #ifdef USE_CS
     _CS = 0;
 #endif
-    unsigned short r=0;
+    unsigned int r=0;
     _DC = 1; // 1=data
    _port.input();
    
@@ -167,12 +167,22 @@
 //    _RD = 0; // add wait
     r |= _port.read();
     _RD = 1;
-    
+    if(convert)
+    {
+        r <<= 8;
+        _RD = 0;
+  //      _RD = 0; // add wait
+        r |= _port.read()>>8; //MSB of port read is blue, LSB is red of next pixel
+        _RD = 1;
+        // gram is 18bit/pixel, if you set 16bit/pixel (cmd 3A), during writing the 16bits are expanded to 18bit
+        // during reading, you read the raw 18bit gram
+        r = RGB24to16((r&0xFF0000)>>16, (r&0xFF00)>>8, r&0xFF);// 18bit pixel padded to 24bits, rrrrrr00_gggggg00_bbbbbb00, converted to 16bit
+    }
 #ifdef USE_CS
     _CS = 1;
 #endif
     _port.output();
-    return r;
+    return (unsigned short)r;
 }
 unsigned int PAR16::rd_reg_data32(unsigned char reg)
 {