Revision 0:caf407d467b1, committed 2010-12-14

Comitter:

Mischa

Date:

Tue Dec 14 06:37:48 2010 +0000

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Dec 14 06:37:48 2010 +0000
@@ -0,0 +1,76 @@
+// Scans through the D/A converter values, and copies a set of A/D converter values to file on USB local filesystem.
+// Connect pin 18 to pin 17.
+
+#include "mbed.h"
+
+AnalogOut aout(p18);
+LocalFileSystem local("local");               // Create the local filesystem under the name "local"
+
+const int N = 100;  //number of samples per D/A value
+int i;
+int n;
+unsigned short x[N];
+short trim = 3; // ADC trim; appears this is added to the ADC readings in two's complement (i.e, -8 gives results in too low readings, 0 gives about correct readings, +3 gives really correct readings for my system, and +7 gives too high readings.) 
+
+// /4 /26 -> mbed
+// /8 /3 -> nice
+// /1 /8 -> 12MHz (max) (ugly)
+// /1 /12 (i.e., 11 in reg.) -> nice
+ 
+int main() {
+    // A/D power on, set A/D clk divider /4
+    LPC_SC->PCONP |= (1 << 12);        // power on, PCADC bit
+    LPC_SC->PCLKSEL0 &= ~(0x1 << 24);  // PCLK_ADC=0,1,2,3 -> CCLK /4,/1,/2,/8
+
+    // software-controlled ADC settings
+    LPC_ADC->ADCR = (0 << 0) // SEL: 0 = no channels selected yet
+              | (11 << 8)    // CLKDIV: PCLK_ADC0 is divided by this number+1 (8 bits)
+              | (0 << 16)    // BURST: 0 = software control 
+              | (1 << 21)    // PDN: 1 = operational
+              | (0 << 24);   // START: 0 = no start
+
+    //p15 = LPC1768 pin  9 = P0.23 = AD0.0 = PINSEL1 bit 15&14 01  
+    //p16 = LPC1768 pin  8 = P0.24 = AD0.1 = PINSEL1 bit 17&16 01
+    //p17 = LPC1768 pin  7 = P0.25 = AD0.2 = PINSEL1 bit 19&18 01
+    //p19 = LPC1768 pin 21 = P1.30 = AD0.4 = PINSEL3 bit 29&28 11 
+    //p20 = LPC1768 pin 20 = P1.31 = AD0.5 = PINSEL3 bit 31&30 11
+    //Same bits in PINMODEi, set these to 10 to disconnect pull up/pull down resistors
+    LPC_PINCON->PINSEL1  &= ~((unsigned int)0x3 << 18);
+    LPC_PINCON->PINSEL1  |=   (unsigned int)0x1 << 18;
+    LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 18);
+    LPC_PINCON->PINMODE1 |=   (unsigned int)0x2 << 18;   // neither pull up nor pull down
+    LPC_ADC->ADCR &= ~0xFF;
+    LPC_ADC->ADCR |= 1 << 2;   // ADC0[2]
+/*  LPC_PINCON->PINSEL3  &= ~((unsigned int)0x3 << 28);
+    LPC_PINCON->PINSEL3  |=   (unsigned int)0x3 << 28;
+    LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 28);
+    LPC_PINCON->PINMODE3 |=   (unsigned int)0x2 << 28;   // neither pull up nor pull down
+    LPC_ADC->ADCR &= ~0xFF;
+    LPC_ADC->ADCR |= 1 << 4;  // ADC0[4]
+*/
+    LPC_ADC->ADTRM&=~0x00F0;
+    LPC_ADC->ADTRM|=(trim<<4) & 0x00F0;   //set the trim
+
+    FILE *fp = fopen("/local/out.txt", "w");  // Open "out.txt" on the local file system for writing
+    for (i=0;i<1024;i++) {
+        aout.write_u16(i<<6);
+        wait(0.000100);
+        for (n=0;n<N;n++) {
+            // Select channel and start conversion
+            LPC_ADC->ADCR |= 1 << 24;
+    
+            // Repeatedly get the sample data until DONE or OVERRUN bit
+            unsigned int data;
+            do {
+               data = LPC_ADC->ADGDR;
+            } while ((data & ((unsigned int)3 << 30)) == 0);
+            x[n]=data;
+        }
+        // Stop conversions    
+        LPC_ADC->ADCR &= ~(1 << 24);
+
+        fwrite(x,sizeof(x[0]),sizeof(x)/sizeof(x[0]),fp);
+    }
+    fclose(fp);
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Dec 14 06:37:48 2010 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e