Diff: targets/hal/TARGET_Atmel/TARGET_SAM_CortexM4/analogin_api.c

Revision:

107:414e9c822e99

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Atmel/TARGET_SAM_CortexM4/analogin_api.c	Tue Apr 05 18:15:12 2016 +0100
@@ -0,0 +1,66 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2015 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 "mbed_assert.h"
+#include "analogin_api.h"
+#include "cmsis.h"
+#include "adc2.h"
+#include "PeripheralPins.h"
+
+extern uint8_t g_sys_init;
+static uint8_t adc_inited = 0;
+
+void analogin_init(analogin_t *obj, PinName pin)
+{
+    MBED_ASSERT(obj);
+    if (g_sys_init == 0) {
+        sysclk_init();
+        system_board_init();
+        g_sys_init = 1;
+    }
+    obj->channel = (enum adc_channel_num)pinmap_peripheral(pin, PinMap_ADC);
+    MBED_ASSERT(obj->channel != NC);
+    if(!adc_inited) { /*ADC hardare to be initialised only once*/
+        adc_enable();
+#if SAMG55
+        adc_select_clock_source_mck(ADC);
+#endif
+        struct adc_config adc_cfg;
+        adc_get_config_defaults(&adc_cfg);
+        adc_cfg.resolution = ADC_16_BITS;
+        adc_init(ADC, &adc_cfg);
+        adc_average_on_single_trigger(ADC);
+        adc_set_trigger(ADC, ADC_TRIG_SW);
+        adc_start_calibration(ADC);
+        adc_inited = 1;
+    }
+    adc_channel_enable(ADC, obj->channel);
+}
+
+uint16_t analogin_read_u16(analogin_t *obj)
+{
+    MBED_ASSERT(obj);
+    adc_channel_get_value(ADC, obj->channel); /*Dummy read of current value*/
+    adc_start_software_conversion(ADC);
+    while (adc_get_interrupt_status(ADC) & (1 << obj->channel));
+    return (uint16_t)adc_channel_get_value(ADC, obj->channel);
+}
+
+float analogin_read(analogin_t *obj)
+{
+    MBED_ASSERT(obj);
+    uint16_t value = analogin_read_u16(obj);
+    return (float)value * (1.0f / (float)0xFFFF);
+}