EmbeddedArtists AB / Mbed 2 deprecated lpc812_exp_solution_analog-in

Solutions for the Analog Input experiments for LPC812 MAX

Dependencies:   lpc812_exp_lib_PCF8591 mbed

Files at this revision

API Documentation at this revision

Revision 0:24709c18bbe0, committed 2013-11-22

Comitter:
embeddedartists
Date:
Fri Nov 22 10:31:23 2013 +0000
Commit message:
First version

Changed in this revision

lpc812_exp_lib_PCF8591.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
diff -r 000000000000 -r 24709c18bbe0 lpc812_exp_lib_PCF8591.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lpc812_exp_lib_PCF8591.lib	Fri Nov 22 10:31:23 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/embeddedartists/code/lpc812_exp_lib_PCF8591/#53bf66c0e0f6

diff -r 000000000000 -r 24709c18bbe0 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Nov 22 10:31:23 2013 +0000
@@ -0,0 +1,107 @@
+#include "mbed.h"
+#include "PCF8591.h"
+ 
+Serial pc(USBTX, USBRX); // tx, rx
+ 
+PCF8591 adc;
+
+float getTrimpotValue()
+{
+    // read a value
+    int v = adc.read(PCF8591::A0);
+        
+    // convert it from 0..255 to 0-3.3V
+    float b = v;
+    return (b / 256) * 3.3;
+}
+
+static void experiment1()
+{
+    pc.printf("Analog input tests\n");
+    while(1) {
+        pc.printf("%f V\n", getTrimpotValue());
+        wait(0.25);
+    }
+}
+
+int getDigit()
+{
+    // read a value
+    int v = adc.read(PCF8591::A0);
+        
+    // convert it from 0..255 to 0-9
+    return (10 * v) / 256;
+}
+
+static void experiment2()
+{
+    pc.printf("Digit input tests\n");
+    while(1) {
+        pc.printf("%d\n", getDigit());
+        wait(0.25);
+    }
+}
+
+int getLightSensorValue(bool filter)
+{
+    static int lastValue = -1;
+
+    // read a value
+    int v = adc.read(PCF8591::A1);
+    
+    if (lastValue == -1) {
+        lastValue = v;
+    }
+    
+    // apply filter
+    if (filter) {
+        lastValue = ((7*lastValue) + v) >> 3;
+    } else {
+        lastValue = v;
+    }
+    
+    return lastValue;
+}
+
+static void experiment3_alt1()
+{
+    pc.printf("Light sensor tests - unfiltered\n");
+    while(1) {
+        pc.printf("%d\n", getLightSensorValue(false));
+        wait(0.25);
+    }
+}
+
+static void experiment3_alt2()
+{
+    pc.printf("Light sensor tests - filtered\n");
+    while(1) {
+        pc.printf("%d\n", getLightSensorValue(true));
+        wait(0.25);
+    }
+}
+
+static void experiment4()
+{
+    int lastValue = -1000;
+    
+    pc.printf("Trimpot tests with threshold\n");
+    while(1) {
+        // read a value
+        int value = adc.read(PCF8591::A0);
+        if (abs(value - lastValue) >= 5) {
+            pc.printf("%d\n", value);
+            lastValue = value;
+        }
+        wait(0.1);
+    }
+}
+
+int main()
+{
+    //experiment1();      // read 0-3.3V
+    //experiment2();      // read digits
+    //experiment3_alt1(); // read light sensor data
+    //experiment3_alt2(); // read filtered light sensor data
+    experiment4();      // read trimpot data, print only big changes
+}
\ No newline at end of file

diff -r 000000000000 -r 24709c18bbe0 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Fri Nov 22 10:31:23 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/a9913a65894f
\ No newline at end of file