Diff: targets/hal/TARGET_NXP/TARGET_LPC43XX/analogout_api.c

Revision:

20:4263a77256ae

Child:

227:7bd0639b8911

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_NXP/TARGET_LPC43XX/analogout_api.c	Tue Sep 10 15:14:19 2013 +0300
@@ -0,0 +1,83 @@
+/* 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.
+ *
+ * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
+ */
+#include "analogout_api.h"
+#include "cmsis.h"
+#include "pinmap.h"
+#include "error.h"
+
+static const PinMap PinMap_DAC[] = {
+    {P_DAC0 , DAC_0, 0x0},
+    {NC     , NC   , 0}
+};
+
+void analogout_init(dac_t *obj, PinName pin) {
+    obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
+    if (obj->dac == (DACName)NC) {
+        error("DAC pin mapping failed");
+    }
+
+    // Configure the pin as GPIO input
+    pin_function(pin, (SCU_PINIO_PULLNONE | 0x0));
+    pin_mode(pin, PullNone);
+    // Select DAC on analog function select register in SCU
+    LPC_SCU->ENAIO[2] |= 1; // Sets pin P4_4 as DAC
+
+    // Set Maximum update rate for DAC */
+    LPC_DAC->CR &= ~DAC_BIAS_EN;
+	
+    analogout_write_u16(obj, 0);
+}
+
+void analogout_free(dac_t *obj) {}
+
+static inline void dac_write(int value) {
+    uint32_t tmp;
+    
+    // Set the DAC output
+    tmp = LPC_DAC->CR & DAC_BIAS_EN;
+    tmp |= DAC_VALUE(value);
+    LPC_DAC->CR = tmp;
+}
+
+static inline int dac_read() {
+    return (DAC_VALUE(LPC_DAC->CR));
+}
+
+void analogout_write(dac_t *obj, float value) {
+    if (value < 0.0f) {
+        dac_write(0);
+    } else if (value > 1.0f) {
+        dac_write(DAC_RANGE);
+    } else {
+        dac_write(value * (float)DAC_RANGE);
+    }
+}
+
+void analogout_write_u16(dac_t *obj, uint16_t value) {
+    dac_write(value >> 6); // 10-bit
+}
+
+float analogout_read(dac_t *obj) {
+    uint32_t value = dac_read();
+    return (float)value * (1.0f / (float)DAC_RANGE);
+}
+
+uint16_t analogout_read_u16(dac_t *obj) {
+    uint32_t value = dac_read(); // 10-bit
+    return (value << 6) | ((value >> 4) & 0x003F);
+}