Diff: main.cpp

Revision:

111:47b0267b8dd4

Parent:

110:e80444a6fe3a

Child:

112:2af5a1ac47d5

--- a/main.cpp	Tue Oct 05 13:18:23 2021 +0000
+++ b/main.cpp	Tue Nov 09 20:33:18 2021 +0000
@@ -1,45 +1,77 @@
 /*
-    Project: 21_BC_Improved_v5 (Improved Binary Counter (while loop) Version)
+    Project: 21_7segmentTest_v5 (Lab Wk 10)
     File: main.cpp
     
-    Displays 8-bit binary count on bar graph display. This version uses a while 
-    loop which provides a much better starting point for an Up/Down counter.
-    
-    Error in pow function use corrected in v. 1.0.
+    This test program confirms hardware operation and demonstrates use of the 
+    7-segement display. It will also be used as the starting point for the 
+    Week 10 lab practical.
+
+    Display "value" from 0 to F_16 to DP (16_10) to all off (17_10) to all on 
+    (17_10) on 7-segment display.
     
-    Note: I tried to use count for the loop counter but this resulted in an 
-    ambiguous name error.
-        
+    Note: This display function takes an integer argument to be display and a 
+    BusOut object (passed by reference) on which to display it as arguments.
+    This differs from the Week 8 Lab display function.
+    
     Written by: Dr. C. S. Tritt
-    Created: 10/5/21 (v. 1.1)
+    Created: 11/9/21 (v. 1.0)
 */
 #include "mbed.h"
 
-DigitalIn uB(USER_BUTTON); // Button is active low (up = 1, down = 0).
-const int bits = 8; // Number of bits to use.
-const int c_max = pow(2, bits) - 1; // Maximum count. pow is type double.
-const int sleepTime = 100; // Sleep time in milliseconds.
-int myCount = 0; // Count to be displayed. Loop counter.
-BusOut barGraph(D2, D3, D4, D5, D6, D7, D8, D9);  // The display.
+void display(int disVal, BusOut &disBus);
+
+Serial pc(USBTX, NC, 9600); // Use for debugging.
+
+const int SLP_TIME = 1000; // Update once per second.
 
-int main() {
+int main(void)
+{
+    // Note that bit sequence is the oposite of what I initially thought they 
+    // would be. That is, pins are listed in low order to high order sequence.
+    BusOut disBus(D9, D8, D7, D6, D5, D4, D3, D2); // The display.
+    int myCount = 0; // Loop count. Rolls over at 18.
+    
     // Test the wiring.
-    ThisThread::sleep_for(400); // For 0.4 seconds.
-    barGraph = 0b01010101;  // Odd bars on (binary).
-    ThisThread::sleep_for(400); // Test even bars for 0.4 seconds. 
-    barGraph = 0b10101010;  // Even bars on (binary).   
-    ThisThread::sleep_for(400); // Test even bars for 0.4 seconds.
-    barGraph = 0xFF;  // All bars on. Hex.
-    ThisThread::sleep_for(400); // For 0.4 seconds.  
+    display(18, disBus);  // All on (binary).
+    ThisThread::sleep_for(2000); // Test even bars for 0.4 seconds.
+    display(17, disBus);  // All off (binary).
+    ThisThread::sleep_for(2000); // Test even bars for 0.4 seconds.
+    
+    // Enter main loop.
+    while(true) {
+        display(myCount, disBus); // Display myCount (count).
+        pc.printf("In main myCount = %d.\n", myCount); // Send count to PC.
+        myCount++; // Increment the count.
+        if (myCount > 18) myCount = 0; // Rollover!
+        ThisThread::sleep_for(SLP_TIME);  // Display value for 1 second.
+    }
+}
 
-    barGraph = myCount; // Initialize the display to myCount.
-    // Enter main loop. 
-    while(true) {
-        while (myCount >= 0 && myCount <= c_max) {
-            barGraph = myCount; // Set display to myCount.
-            ThisThread::sleep_for(sleepTime);  // Display value for 0.1 seconds.
-            myCount++;
-        }
-        myCount = 0;
-    }
+void display(int disVal, BusOut &disBus){
+    // 7-segment, active low look-up-table. Displays Hex 0 to F, dp, all off 
+    // and all on. 
+    const int lutAL[] = { 
+    0b00000011, // 0 = 0
+    0b10011111, // 1 = 1
+    0b00100101, // 2 = 2
+    0b00001101, // 3 = 3
+    0b10011001, // 4 = 4
+    0b01001001, // 5 = 5
+    0b01000001, // 6 = 6
+    0b00011111, // 7 = 7
+    0b00000001, // 8 = 8
+    0b00001001, // 9 = 9
+    0b00010001, // 10 = a
+    0b11000001, // 11 = b
+    0b11100101, // 12 = c
+    0b10000101, // 13 = d
+    0b01100001, // 14 = e
+    0b01110001, // 15 = f
+    0b11111110, // 16 = dp
+    0b11111111, // 17 = All off
+    0b00000000  // 18 = All on
+    //abcdefg_dp – 7-segement output codes 0 to 18.
+    };
+    disBus = lutAL[disVal];
+    pc.printf("In display, disVal = %d\n", disVal);
 }
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