Added readcommand8 to GFX (#220)

Author: makermelissa

Adafruit_SPITFT.cpp

@@ -1729,6 +1729,29 @@ void Adafruit_SPITFT::sendCommand(uint8_t commandByte, const uint8_t *dataBytes,
     SPI_END_TRANSACTION();
 }
 
+/*!
+ @brief   Read 8 bits of data from display configuration memory (not RAM).
+ This is highly undocumented/supported and should be avoided,
+ function is only included because some of the examples use it.
+ @param   command
+ The command register to read data from.
+ @param   index
+ The byte index into the command to read from.
+ @return  Unsigned 8-bit data read from display register.
+ */
+/**************************************************************************/
+uint8_t Adafruit_SPITFT::readcommand8(uint8_t commandByte, uint8_t index) {
+  uint8_t result;
+  startWrite();
+  SPI_DC_LOW();     // Command mode
+  spiWrite(commandByte);
+  SPI_DC_HIGH();    // Data mode
+  do {
+    result = spiRead();
+  } while(index--); // Discard bytes up to index'th
+  endWrite();
+  return result;
+}
 
 // -------------------------------------------------------------------------
 // Lowest-level hardware-interfacing functions. Many of these are inline and

Adafruit_SPITFT.h

@@ -189,6 +189,7 @@ class Adafruit_SPITFT : public Adafruit_GFX {
     void         endWrite(void);
     void         sendCommand(uint8_t commandByte, uint8_t *dataBytes = NULL, uint8_t numDataBytes = 0);
     void         sendCommand(uint8_t commandByte, const uint8_t *dataBytes, uint8_t numDataBytes);
+    uint8_t      readcommand8(uint8_t commandByte, uint8_t index = 0);
 
     // These functions require a chip-select and/or SPI transaction
     // around them. Higher-level graphics primitives might start a

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit GFX Library
-version=1.4.14
+version=1.5.0
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=Adafruit GFX graphics core library, this is the 'core' class that all our other graphics libraries derive from.