Diff: TLC5940Servo.cpp

Revision:

0:9fc434ff7a03

Child:

2:1d2251574d35

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TLC5940Servo.cpp	Tue Oct 21 00:02:48 2014 +0000
@@ -0,0 +1,71 @@
+#include "TLC5940Servo.h"
+
+TLC5940Servo::TLC5940Servo(PinName MOSI, PinName SCLK, PinName XLAT, PinName BLANK, 
+        PinName GSCLK, const int number) : number(number), spi(MOSI, NC, SCLK), gsclk(GSCLK),
+                                           blank(BLANK), xlat(XLAT), newData(false), need_xlat(false)
+{   
+    // Configure SPI to 12 bits and SPI_SPEED
+    spi.format(12, 0);
+    spi.frequency(SPI_SPEED);
+    
+    // Set output pin states
+    xlat = 0;
+    blank = 1;
+    
+    // Call the reset function every 4096 PWM outputs
+    reset_ticker.attach_us(this, &TLC5940Servo::reset, (1000000.0/GSCLK_SPEED) * 4096.0);
+    
+    // Configure FastPWM output for GSCLK frequency at 50% duty cycle
+    gsclk.period_us(1000000.0/GSCLK_SPEED);
+    gsclk.write(.5);
+
+    // Create a data buffer to store the current Servo states
+    dataBuffer = new int[16 * number]();
+}
+
+TLC5940Servo::~TLC5940Servo()
+{
+    // Delete the buffer
+    delete[] dataBuffer;
+}
+
+
+int& TLC5940Servo::operator[](int index)
+{
+    // Return the start of the correct data chunk
+    newData = true;
+    return dataBuffer[index];
+}
+
+void TLC5940Servo::reset()
+{
+    gsclk.write(0); // turn off gsclk
+    blank = 1; // start reset
+    
+    // latch data if new data was written
+    if (need_xlat) {
+        xlat = 1;
+        xlat = 0;
+        
+        need_xlat = false;
+    }
+    
+    blank = 0; // turn off reset
+    gsclk.write(.5); // restart gsclk
+
+    if (newData) {
+        
+        // Send GS data backwards - this makes the GS_buffer[0] index correspond to OUT0 
+        for (int i = (16 * number) - 1; i >= 0; i--)
+        {
+            // Get the lower 12 bits of the buffer and send
+            spi.write(dataBuffer[i] & 0xFFF);
+        }
+        
+        // Latch after current GS data is done being displayed
+        need_xlat = true;
+        
+        // No new data to send (we just sent it!)
+        newData = false;
+    }
+}
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