Revision 0:b4a97c42da72, committed 2014-07-03

Comitter:

acracan

Date:

Thu Jul 03 07:40:40 2014 +0000

Commit message:

InterruptIn demonstration.

Changed in this revision

diff -r 000000000000 -r b4a97c42da72 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jul 03 07:40:40 2014 +0000
@@ -0,0 +1,151 @@
+#include "mbed.h"
+
+InterruptIn sig(D5);
+Timer sigTimer;
+Serial pc(USBTX, USBRX);
+
+int sigPeriod = 0;
+
+// Define display ports
+const PinName cellPins[] = {A0, A1, A2, A3};
+const PinName segPins[] = {D13, D12, D11, D10, D9, D8, D7, D6};
+                        //  A    B    C    D   E   F   G   Dot
+DigitalOut *cellPorts[4];
+DigitalOut *segPorts[8];
+
+Timer displayTimer;
+
+namespace SevenSegments{
+    enum Element {
+      SegA = 1,
+      SegB = 2,
+      SegC = 4,
+      SegD = 8,
+      SegE = 16,
+      SegF = 32,
+      SegG = 64,
+      SegDot = 128
+    };
+    
+    const uint8_t digits[] = {
+      SegA | SegB | SegC | SegD | SegE | SegF,
+      SegB | SegC,
+      SegA | SegB | SegG | SegE | SegD,
+      SegA | SegB | SegG | SegC | SegD,
+      SegF | SegB | SegG | SegC,
+      SegA | SegF | SegG | SegC | SegD,
+      SegA | SegF | SegG | SegE | SegC | SegD,
+      SegA | SegB | SegC,
+      SegA | SegB | SegC | SegD | SegE | SegF | SegG,
+      SegA | SegB | SegG | SegF | SegC | SegD
+    };
+};
+
+uint8_t cellValues[4];
+
+Timer periodUpdateTimer;
+
+// Function prototypes
+void displaySevenSegs(uint8_t cellValues[]);
+void valueToBcd(int val, uint8_t cellValues[]);
+void updateDisplayedValue(int val, uint8_t cellValues[]);
+void onRisingEdge();
+
+int main()
+{
+    displayTimer.start();
+    // Initialize cell ports
+    for (int i = 0; i < 4; i++) {
+      cellPorts[i] = new DigitalOut(cellPins[i]);
+      *cellPorts[i] = 1;
+    }
+    // Initialize segment ports
+    for (int i = 0; i < 8; i++)
+      segPorts[i] = new DigitalOut(segPins[i]);
+
+    sig.mode(PullNone);
+    sig.rise(onRisingEdge);
+    sigTimer.start();
+    periodUpdateTimer.start();
+    while(1) {
+        displaySevenSegs(cellValues);
+        updateDisplayedValue(sigPeriod, cellValues);
+    }
+}
+
+void onRisingEdge()
+{
+    static int queue[128], queueStart = 0, queueEnd = 0;
+    static uint64_t sum = 0;
+    int time;
+    
+    time = sigTimer.read_us();
+    sigTimer.reset();
+    if (queueStart == queueEnd && sum != 0) {
+        sum -= queue[queueStart];
+        queueStart = (queueStart + 1) & 127;
+    }
+    sum += time;
+    queue[queueEnd] = time;
+    queueEnd = (queueEnd + 1) & 127;
+    
+    if (queueStart == queueEnd)
+        sigPeriod = sum / 128;
+    else
+        sigPeriod = sum / ((queueEnd + 128 - queueStart) & 127);
+}
+
+void bcdToSevenSegs(uint8_t val)
+{
+  uint8_t segs;
+
+  segs = SevenSegments::digits[val];
+  for (int s = 0; s < 8; s++) {
+    if (segs & (1 << s))
+      // Enable segment
+      *segPorts[s] = 1;
+    else
+      // Disable segment
+      *segPorts[s] = 0;
+  }
+}
+
+void displaySevenSegs(uint8_t cellValues[])
+{
+    static bool activeCells[5] = {true, false, false, false, false};
+        
+    if (displayTimer.read_us() < 1000)
+        return;
+    displayTimer.reset();
+    for (int i = 4; i > 0; i--)
+    activeCells[i] = activeCells[i - 1];
+    activeCells[0] = activeCells[4];
+    // Turn off all cells
+    for (int i = 0; i < 4; i++)
+    *cellPorts[i] = 1;
+    // Change cell value
+    for (int i = 0; i < 4; i++)
+    if (activeCells[i])
+        bcdToSevenSegs(cellValues[i]);
+    // Turn on active cell
+    for (int i = 0; i < 4; i++)
+    if (activeCells[i])
+      *cellPorts[i] = 0;
+}
+
+
+void valueToBcd(int val, uint8_t cellValues[])
+{
+  for (int i = 3; i >= 0; i--) {
+    cellValues[i] = val % 10;
+    val /= 10;
+  }
+}
+
+void updateDisplayedValue(int val, uint8_t cellValues[])
+{
+    if (periodUpdateTimer.read_ms() < 100)
+        return;
+    periodUpdateTimer.reset();
+    valueToBcd(val, cellValues);
+}
\ No newline at end of file

diff -r 000000000000 -r b4a97c42da72 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Jul 03 07:40:40 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/04dd9b1680ae
\ No newline at end of file