Diff: targets/hal/TARGET_NORDIC/TARGET_NRF51822/analogin_api.c

Revision:

85:e1a8e879a6a9

Child:

217:d0ccc61c1fd4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_NORDIC/TARGET_NRF51822/analogin_api.c	Fri Feb 07 18:00:11 2014 +0000
@@ -0,0 +1,72 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "analogin_api.h"
+#include "cmsis.h"
+#include "pinmap.h"
+#include "error.h"
+
+#define ANALOGIN_MEDIAN_FILTER      1
+#define ADC_10BIT_RANGE             0x3FF
+#define ADC_RANGE    ADC_10BIT_RANGE
+
+static const PinMap PinMap_ADC[] = {
+    {p1, ADC0_0, 4},
+    {p2, ADC0_0, 8},
+    {p3, ADC0_0, 16},
+    {p4, ADC0_0, 32},
+    {p5, ADC0_0, 64},
+    {p6, ADC0_0, 128},
+    {NC   , NC    , 0}
+};
+
+void analogin_init(analogin_t *obj, PinName pin) {
+    int analogInputPin=0;
+    const PinMap *map = PinMap_ADC;
+    
+    obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC); //(NRF_ADC_Type *)
+    if (obj->adc == (ADCName)NC) {
+        error("ADC pin mapping failed");
+    }
+        
+    while (map->pin != NC) {
+        if (map->pin == pin){
+            analogInputPin = map->function;
+            break;
+        }
+        map++;
+    }
+    
+    NRF_ADC->ENABLE = ADC_ENABLE_ENABLE_Enabled; 
+    NRF_ADC->CONFIG = (ADC_CONFIG_RES_10bit << ADC_CONFIG_RES_Pos) |
+                      (ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling<< ADC_CONFIG_INPSEL_Pos) |
+                      (ADC_CONFIG_REFSEL_SupplyOneThirdPrescaling << ADC_CONFIG_REFSEL_Pos) |
+                      (analogInputPin << ADC_CONFIG_PSEL_Pos) |
+                      (ADC_CONFIG_EXTREFSEL_None << ADC_CONFIG_EXTREFSEL_Pos);    
+}
+
+uint16_t analogin_read_u16(analogin_t *obj) {
+    NRF_ADC->TASKS_START = 1;
+    while ( ( (NRF_ADC->BUSY & ADC_BUSY_BUSY_Msk) >> ADC_BUSY_BUSY_Pos) == ADC_BUSY_BUSY_Busy)
+    {
+    }
+    
+    return (uint16_t)NRF_ADC->RESULT; // 10 bit
+}
+
+float analogin_read(analogin_t *obj) {
+    uint16_t value = analogin_read_u16(obj);
+    return (float)value * (1.0f / (float)ADC_RANGE);
+}