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git.gir.st - tmk_keyboard.git/blob - tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC23XX/analogout_api.c
1 /* mbed Microcontroller Library
2 * Copyright (c) 2006-2013 ARM Limited
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 #include "mbed_assert.h"
17 #include "analogout_api.h"
21 static const PinMap PinMap_DAC
[] = {
26 void analogout_init(dac_t
*obj
, PinName pin
) {
27 obj
->dac
= (DACName
)pinmap_peripheral(pin
, PinMap_DAC
);
28 MBED_ASSERT(obj
->dac
!= (DACName
)NC
);
30 // power is on by default, set DAC clk divider is /4
31 LPC_SC
->PCLKSEL0
&= ~(0x3 << 22);
33 // map out (must be done before accessing registers)
34 pinmap_pinout(pin
, PinMap_DAC
);
36 analogout_write_u16(obj
, 0);
39 void analogout_free(dac_t
*obj
) {}
41 static inline void dac_write(int value
) {
42 value
&= 0x3FF; // 10-bit
45 LPC_DAC
->DACR
= (0 << 16) // bias = 0
49 static inline int dac_read() {
50 return (LPC_DAC
->DACR
>> 6) & 0x3FF;
53 void analogout_write(dac_t
*obj
, float value
) {
56 } else if (value
> 1.0f
) {
59 dac_write(value
* (float)0x3FF);
63 void analogout_write_u16(dac_t
*obj
, uint16_t value
) {
64 dac_write(value
>> 6); // 10-bit
67 float analogout_read(dac_t
*obj
) {
68 uint32_t value
= dac_read();
69 return (float)value
* (1.0f
/ (float)0x3FF);
72 uint16_t analogout_read_u16(dac_t
*obj
) {
73 uint32_t value
= dac_read(); // 10-bit
74 return (value
<< 6) | ((value
>> 4) & 0x003F);