Diff: main.cpp

Revision:

0:3ca2fd0d22ba

Child:

1:f66778df0d8d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Jul 08 23:56:34 2016 +0000
@@ -0,0 +1,156 @@
+// TLC5940 Tester
+//
+// This is a simple test bed for the TLC5940 chips.  We use the same
+// interface class used in the Pinscape v2 firmware, but omit all of the
+// other functionality of the Pinscape software.  This does nothing
+// besides drive the TLC5940 chips.
+//
+// The GPIO pin connections to the TLC5940 chips are configured by default 
+// for the Pinscape Expansion Boards.  Edit the "TLC5940 configuration" 
+// section below to change the pin assignments.
+
+#include "mbed.h"
+#include "TLC5940.h"
+
+// Operation mode:
+//
+//   0 = ALL ON mode - all outputs continuously turned on
+//
+//   1 = Up/Down mode - all outputs ramped from off to full brightness
+//       and back every couple of seconds
+//
+//   2 = Sweep mode - outputs ramped up one at a time then ramped 
+//       down one at a time
+//
+const int MODE = 2;           
+
+// TLC5940 configuration
+const int NCHIPS    = 2;      // number of TLC5940 chips in daisy chain
+const PinName SCLK  = PTC5;
+const PinName SIN   = PTC6;
+const PinName GSCLK = PTA1;
+const PinName BLANK = PTC7;
+const PinName XLAT  = PTC10;
+
+
+// diagnostic LED segments
+DigitalOut ledR(LED1), ledG(LED2), ledB(LED3);
+
+// adjust an output value by an increment, keeping it within range
+static void adjustOut(int &out, int inc)
+{
+    out += inc;
+    if (out < 0)
+        out = 0;
+    else if (out > 4095)
+        out = 4095;
+}
+
+int main() 
+{
+    // set up the tlc5940 interface
+    TLC5940 tlc5940(SCLK, SIN, GSCLK, BLANK, XLAT, NCHIPS);
+    
+    // start the tlc5940 clock
+    tlc5940.start();
+    
+    // enable the outputs
+    tlc5940.enable(true);
+    
+    // current status for ramp mode
+    struct
+    {
+        int dir;
+        int val;
+    } ramp = { 1, 0 };
+    
+    // current status for sweep mode
+    struct
+    {
+        int out;
+        int dir;
+        int val;
+    } sweep = { 0, 4, 0 };
+     
+    // in MODE 0, set all outputs to full on initially
+    if (MODE == 0)
+    {
+        for (int i = 0 ; i < NCHIPS*16 ; ++i)
+            tlc5940.set(i, 4095);
+    }
+    
+    // heartbeat flasher
+    int t = 0;
+    int hb = 0;
+
+    // send tlc updates forever
+    for (;;)
+    {
+        // send TLC updates as needed
+        tlc5940.send();
+        
+        // pause between operations
+        wait_us(500);
+        
+        // update outputs according to the current mode
+        switch (MODE)
+        {
+        case 1:
+            // ramp up/down mode - all outputs ramp on every loop
+            
+            // switch direction if at the top or bottom of the ramp
+            if ((ramp.dir > 0 && ramp.val == 4095) || (ramp.dir < 0 && ramp.val == 0))
+                ramp.dir = -ramp.dir;
+                
+            // adjust all outputs
+            adjustOut(ramp.val, ramp.dir);
+            for (int i = 0 ; i < NCHIPS*16 ; ++i)
+                tlc5940.set(i, ramp.val);
+               
+            // done 
+            break;
+            
+        case 2:
+            // sweep up/down mode - adjust one output at a time
+            
+            // at top or bottom, move to next output
+            if ((sweep.dir > 0 && sweep.val == 4095) || (sweep.dir <= 0 && sweep.val == 0))
+            {
+                // advance to the next output
+                if (++sweep.out < NCHIPS*16)
+                {
+                    // at next out - start at other end of ramp
+                    sweep.val = (sweep.dir > 0 ? 0 : 4095);
+                }
+                else
+                {
+                    // past last output - wrap and reverse the ramp direction
+                    sweep.out = 0;
+                    sweep.dir = -sweep.dir;
+                }
+            }
+            
+            // adjust this output
+            adjustOut(sweep.val, sweep.dir);
+            tlc5940.set(sweep.out, sweep.val);
+            
+            // done
+            break;
+        }
+        
+        // update the heartbeat if needed
+        if (t++ > 1000)
+        {
+            ledR = 1; ledB = 1; ledG = 1;
+            switch (hb++)
+            {
+            case 0: ledR = 0; ledG = 0; break;  // yellow
+            case 1: ledB = 0; ledR = 0; break;  // purple
+            case 2: ledG = 0; break;            // green
+            case 3: ledB = 0; break;            // blue
+            }
+            hb %= 3;
+            t = 0;
+        }
+    }
+}