Diff: main.cpp

Revision:

0:3f9f4f8c8b2d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Sep 05 19:00:01 2010 +0000
@@ -0,0 +1,91 @@
+#include "mbed.h"
+
+SPI spi(p5, p6, p7); // mosi, miso, sclk
+DigitalOut cs(p8);
+
+Serial pc(USBTX, USBRX); // tx, rx
+
+// Write configuration.  CFG is assumed to be a 6 byte array
+void write_cfg(int * cfg) {
+    // Chip enable
+    cs = 0;
+    // Send 0x01 for Writing Configuration Register Group
+    spi.write(0x01);
+    int i;
+    // Send 6 bytes of cfg
+    for (i=0; i<6; i++)
+        spi.write(cfg[i]);
+    // Done sending
+    cs = 1;
+}
+
+// Read configuration. cfg is assumed to be a 7 int buffer
+void read_cfg(int * cfg) {
+    cs = 0;
+    // Select the first board
+    spi.write(0x80);
+    // Read config
+    spi.write(0x02);
+    int i;
+    for (i=0; i<7; i++)
+        cfg[i] = spi.write(0xAA);
+    cs = 1;
+}
+
+void start_ADC() {
+    cs = 0;
+    spi.write(0x10);
+    cs = 1;
+}
+
+// buf is a 19 int array
+void read_batt(int * buf) {
+    cs = 0;
+    spi.write(0x80);
+    spi.write(0x04);
+    int i;
+    for (i=0; i<19; i++) {
+        buf[i] = spi.write(0xAA);
+    }
+    cs = 1;
+}
+
+// buf is a 19 int array, out is a 12 int array
+void conv_batt(int * buf, int * out) {
+    out[0] = (buf[0] & 0xFF) | (buf[1] & 0x0F) << 8;
+    out[1] = ((buf[1] & 0xF0) >> 4) | ((buf[2] & 0xFF) << 4);
+    
+    out[2] = (buf[3] & 0xFF) | (buf[4] & 0x0F) << 8;
+    out[3] = (buf[4] & 0xF0) >> 4 | (buf[5] & 0xFF) << 4;
+    out[4] = (buf[6] & 0xFF) | (buf[7] & 0x0F) << 8;
+    out[5] = (buf[7] & 0xF0) >> 4| (buf[8] & 0xFF) << 4;
+    out[6] = (buf[9] & 0xFF) | (buf[10] & 0x0F) << 8;
+    out[7] = (buf[10] & 0xF0) >> 4| (buf[12] & 0xFF) << 4;
+    out[8] = (buf[12] & 0xFF) | (buf[13] & 0x0F) << 8;
+    out[9] = (buf[13] & 0xF0) >> 4| (buf[14] & 0xFF) << 4;
+    out[10] = (buf[15] & 0xFF) | (buf[16] & 0x0F) << 8;
+    out[11] = (buf[16] & 0xF0) >> 4| (buf[17] & 0xFF) << 4;
+}
+
+int main() {
+    // Setup the spi for 8 bit data, high steady state clock,
+    // second edge capture, with a 0.5MHz clock rate
+    spi.format(8,0);
+    spi.frequency(100000);
+    int cfg[6] = { 0xE7, 0x00, 0x00, 0x00, 0x00, 0xFA };
+    write_cfg(cfg);
+    wait(0.2);
+    while(1) {
+        int buf[19];
+        int i;
+        start_ADC();
+        wait(0.1);
+        read_batt(buf);
+        int batt[12];
+        conv_batt(buf, batt);
+        for (i=0;i<12;i++)
+            pc.printf("%d: %f \r\n", i, batt[i] * 1.5 / 1000);
+        pc.printf("\r\n=============================\r\n");
+        wait(2);
+    }
+}
\ No newline at end of file