Merge pull request #411 from ADVANSEE/cc2538-adc

cc2538: Add adc driver and example

examples/cc2538dk/cc2538-demo.c

@@ -50,6 +50,8 @@
  *                - BTN_DOWN turns on LEDS_REBOOT and causes a watchdog reboot
  *                - BTN_UP to soft reset (SYS_CTRL_PWRDBG::FORCE_WARM_RESET)
  *                - BTN_LEFT and BTN_RIGHT flash the LED defined as LEDS_BUTTON
+ * - ADC sensors  : On-chip VDD / 3 and temperature, and ambient light sensor
+ *                  values are printed over UART periodically.
  * - UART         : Every LOOP_INTERVAL the EM will print something over the
  *                  UART. Receiving an entire line of text over UART (ending
  *                  in \\r) will cause LEDS_SERIAL_IN to toggle
@@ -68,6 +70,7 @@
 #include "dev/leds.h"
 #include "dev/uart.h"
 #include "dev/button-sensor.h"
+#include "dev/adc-sensor.h"
 #include "dev/watchdog.h"
 #include "dev/serial-line.h"
 #include "dev/sys-ctrl.h"
@@ -111,6 +114,7 @@ rt_callback(struct rtimer *t, void *ptr)
 /*---------------------------------------------------------------------------*/
 PROCESS_THREAD(cc2538_demo_process, ev, data)
 {
+  int16_t value;
 
   PROCESS_EXITHANDLER(broadcast_close(&bc))
 
@@ -127,7 +131,18 @@ PROCESS_THREAD(cc2538_demo_process, ev, data)
 
     if(ev == PROCESS_EVENT_TIMER) {
       leds_on(LEDS_PERIODIC);
-      printf("Counter = 0x%08x\n", counter);
+      printf("-----------------------------------------\n"
+             "Counter = 0x%08x\n", counter);
+
+      value = adc_sensor.value(ADC_SENSOR_VDD_3);
+      printf("VDD = %d mV\n", value * (3 * 1190) / (2047 << 4));
+
+      value = adc_sensor.value(ADC_SENSOR_TEMP);
+      printf("Temperature = %d mC\n",
+             25000 + ((value >> 4) - 1422) * 10000 / 42);
+
+      value = adc_sensor.value(ADC_SENSOR_ALS);
+      printf("Ambient light sensor = %d raw\n", value);
 
       etimer_set(&et, CLOCK_SECOND);
       rtimer_set(&rt, RTIMER_NOW() + LEDS_OFF_HYSTERISIS, 1,