How to add a COAP resource to read ADC input from DIO23 in Contiki cc26xx-web-demo on CC2650 LaunchPad.

To add a COAP resource to read ADC input from DIO23 in Contiki cc26xx-web-demo on CC2650 LaunchPad, you have to add the following code with "+" into your cc26xx-web-demo.c, cc26xx-web-demo.h, coap-server.c, and res-sensors.c.

1. /examples/cc26xx/cc26xx-web-demo/cc26xx-web-demo.c
@@ -55,9 +55,15 @@
 #include
 #include
 #include
+
+#include "ti-lib.h"
+#include "driverlib/aux_adc.h"
+#include "driverlib/aux_wuc.h"
+
 /*---------------------------------------------------------------------------*/
 PROCESS_NAME(cetic_6lbr_client_process);
 PROCESS(cc26xx_web_demo_process, "CC26XX Web Demo");
+PROCESS(adc_process, "ADC process");
 /*---------------------------------------------------------------------------*/
 /*
  * Update sensor readings in a staggered fashion every SENSOR_READING_PERIOD
@@ -84,6 +90,9 @@ static struct uip_icmp6_echo_reply_notification echo_reply_notification;
 static struct etimer echo_request_timer;
 int def_rt_rssi = 0;
 #endif
+
+uint16_t singleSample;
+
 /*---------------------------------------------------------------------------*/
 process_event_t cc26xx_web_demo_publish_event;
 process_event_t cc26xx_web_demo_config_loaded_event;
@@ -110,6 +119,9 @@ DEMO_SENSOR(batmon_temp, CC26XX_WEB_DEMO_SENSOR_BATMON_TEMP,
 DEMO_SENSOR(batmon_volt, CC26XX_WEB_DEMO_SENSOR_BATMON_VOLT,
             "Battery Volt", "battery-volt", "batmon_volt",
             CC26XX_WEB_DEMO_UNIT_VOLT);
+DEMO_SENSOR(adc_dio23, CC26XX_WEB_DEMO_SENSOR_ADC_DIO23,
+            "ADC DIO23", "adc-dio23", "adc_dio23",
+            CC26XX_WEB_DEMO_UNIT_VOLT);
 /* Sensortag sensors */
 #if BOARD_SENSORTAG
@@ -464,6 +476,14 @@ get_batmon_reading(void *data)
     }
   }

+  if(adc_dio23_reading.publish) {
+    if(1) {
+      buf = adc_dio23_reading.converted;
+      memset(buf, 0, CC26XX_WEB_DEMO_CONVERTED_LEN);
+      snprintf(buf, CC26XX_WEB_DEMO_CONVERTED_LEN, "%d", singleSample);
+    }
+  }
+
   ctimer_set(&batmon_timer, next, get_batmon_reading, NULL);
 }
 /*---------------------------------------------------------------------------*/
@@ -825,6 +845,7 @@ init_sensors(void)

   list_add(sensor_list, &batmon_temp_reading);
   list_add(sensor_list, &batmon_volt_reading);
+  list_add(sensor_list, &adc_dio23_reading);
   SENSORS_ACTIVATE(batmon_sensor);

 #if BOARD_SENSORTAG
@@ -864,6 +885,7 @@ PROCESS_THREAD(cc26xx_web_demo_process, ev, data)

   /* Start all other (enabled) processes first */
   process_start(&httpd_simple_process, NULL);
+  process_start(&adc_process, NULL);
 #if CC26XX_WEB_DEMO_COAP_SERVER
   process_start(&coap_server_process, NULL);
 #endif
@@ -966,6 +988,56 @@ PROCESS_THREAD(cc26xx_web_demo_process, ev, data)

   PROCESS_END();
 }
+
+PROCESS_THREAD(adc_process, ev, data)
+{
+  PROCESS_BEGIN();
+  static struct etimer et_adc;
+  while(1)
+  {
+         etimer_set(&et_adc, CLOCK_SECOND*5);
+         PROCESS_WAIT_EVENT();
+         if(etimer_expired(&et_adc)) {
+               //intialisation of ADC
+               ti_lib_aon_wuc_aux_wakeup_event(AONWUC_AUX_WAKEUP);
+               while(!(ti_lib_aon_wuc_power_status_get() & AONWUC_AUX_POWER_ON))
+               { }
+
+               // Enable clock for ADC digital and analog interface (not currently enabled in driver)
+               // Enable clocks
+               ti_lib_aux_wuc_clock_enable(AUX_WUC_ADI_CLOCK | AUX_WUC_ANAIF_CLOCK | AUX_WUC_SMPH_CLOCK);
+               while(ti_lib_aux_wuc_clock_status(AUX_WUC_ADI_CLOCK | AUX_WUC_ANAIF_CLOCK | AUX_WUC_SMPH_CLOCK) != AUX_WUC_CLOCK_READY)
+               { }
+               //printf("clock selected\r\n");
+
+               // Connect AUX IO7 (DIO23, but also DP2 on XDS110) as analog input.
+               AUXADCSelectInput(ADC_COMPB_IN_AUXIO7);
+               //printf("input selected\r\n");
+
+               // Set up ADC range
+               // AUXADC_REF_FIXED = nominally 4.3 V
+               AUXADCEnableSync(AUXADC_REF_FIXED,  AUXADC_SAMPLE_TIME_2P7_US, AUXADC_TRIGGER_MANUAL);
+               //printf("init adc --- OK\r\n");
+
+               //Trigger ADC converting
+               AUXADCGenManualTrigger();
+               //printf("trigger --- OK\r\n");
+
+               //reading adc value
+               singleSample = AUXADCReadFifo();
+
+               printf("%d mv on ADC\r\n",singleSample);
+
+               //shut the adc down
+               AUXADCDisable();
+               //printf("disable --- OK\r\n");
+               get_batmon_reading(NULL);
+
+               etimer_reset(&et_adc);
+               }
+  }
+  PROCESS_END();
+}
 
2./examples/cc26xx/cc26xx-web-demo/cc26xx-web-demo.h
@@ -146,6 +146,7 @@
 #define CC26XX_WEB_DEMO_SENSOR_MPU_GYRO_X    12
 #define CC26XX_WEB_DEMO_SENSOR_MPU_GYRO_Y    13
 #define CC26XX_WEB_DEMO_SENSOR_MPU_GYRO_Z    14
+#define CC26XX_WEB_DEMO_SENSOR_ADC_DIO23     15
 /*---------------------------------------------------------------------------*/
 extern process_event_t cc26xx_web_demo_publish_event;
 extern process_event_t cc26xx_web_demo_config_loaded_event;

3. /examples/cc26xx/cc26xx-web-demo/coap-server.c
@@ -50,6 +50,7 @@ extern resource_t res_leds;

 extern resource_t res_batmon_temp;
 extern resource_t res_batmon_volt;
+extern resource_t res_adc_dio23;

 extern resource_t res_device_sw;
 extern resource_t res_device_hw;
@@ -133,6 +134,7 @@ PROCESS_THREAD(coap_server_process, ev, data)

   rest_activate_resource(&res_batmon_temp, "sen/batmon/temp");
   rest_activate_resource(&res_batmon_volt, "sen/batmon/voltage");
+  rest_activate_resource(&res_adc_dio23, "adc/dio23");

   rest_activate_resource(&res_device_hw, "dev/mdl/hw");
   rest_activate_resource(&res_device_sw, "dev/mdl/sw");

4. examples/cc26xx/cc26xx-web-demo/resources/res-sensors.c
@@ -111,12 +111,24 @@ res_get_handler_batmon_volt(void *request, void *response, uint8_t *buffer,
                       buffer, preferred_size, offset);
 }
 /*---------------------------------------------------------------------------*/
+static void
+res_get_handler_adc_dio23(void *request, void *response, uint8_t *buffer,
+                            uint16_t preferred_size, int32_t *offset)
+{
+  res_get_handler_all(CC26XX_WEB_DEMO_SENSOR_ADC_DIO23, request, response,
+                      buffer, preferred_size, offset);
+}
+/*---------------------------------------------------------------------------*/
 RESOURCE(res_batmon_temp, "title=\"Battery Temp\";rt=\"C\"",
          res_get_handler_batmon_temp, NULL, NULL, NULL);
 /*---------------------------------------------------------------------------*/
 RESOURCE(res_batmon_volt, "title=\"Battery Voltage\";rt=\"mV\"",
          res_get_handler_batmon_volt, NULL, NULL, NULL);
 /*---------------------------------------------------------------------------*/
+/*---------------------------------------------------------------------------*/
+RESOURCE(res_adc_dio23, "title=\"ADC DIO23\";rt=\"mV\"",
+         res_get_handler_adc_dio23, NULL, NULL, NULL);
+/*---------------------------------------------------------------------------*/
 #if BOARD_SENSORTAG
 /*---------------------------------------------------------------------------*/
 /* MPU resources and handler: Accelerometer and Gyro */

Build cc26xx-web-demo for CC2650 LaunchPad by "make TARGET=srf06-cc26xx BOARD=launchpad/cc2650 cc26xx-web-demo.bin" and download cc26xx-web-demo.bin to your CC2650 LaunchPad. Let it join 6lbr and you should see resource adc/dio23 on COAP interface. You can press Get button to get the ADC reading from DIO23. Try to connect different voltage (0-3.6V) to test.