analogout_api.c 2.8 KB

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  1. /* mbed Microcontroller Library
  2. * Copyright (c) 2017, STMicroelectronics
  3. * All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions are met:
  7. *
  8. * 1. Redistributions of source code must retain the above copyright notice,
  9. * this list of conditions and the following disclaimer.
  10. * 2. Redistributions in binary form must reproduce the above copyright notice,
  11. * this list of conditions and the following disclaimer in the documentation
  12. * and/or other materials provided with the distribution.
  13. * 3. Neither the name of STMicroelectronics nor the names of its contributors
  14. * may be used to endorse or promote products derived from this software
  15. * without specific prior written permission.
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20. * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  21. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23. * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  24. * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27. */
  28. #include "mbed_assert.h"
  29. #include "analogout_api.h"
  30. #if DEVICE_ANALOGOUT
  31. #include "cmsis.h"
  32. #include "pinmap.h"
  33. #include "mbed_error.h"
  34. #include "PeripheralPins.h"
  35. #define DAC_RANGE (0xFFF) // 12 bits
  36. #define DAC_NB_BITS (12)
  37. static inline void dac_write(dac_t *obj, int value)
  38. {
  39. HAL_DAC_SetValue(&obj->handle, obj->channel, DAC_ALIGN_12B_R, (value & DAC_RANGE));
  40. HAL_DAC_Start(&obj->handle, obj->channel);
  41. }
  42. static inline int dac_read(dac_t *obj)
  43. {
  44. return (int)HAL_DAC_GetValue(&obj->handle, obj->channel);
  45. }
  46. void analogout_write(dac_t *obj, float value)
  47. {
  48. if (value < 0.0f) {
  49. dac_write(obj, 0); // Min value
  50. } else if (value > 1.0f) {
  51. dac_write(obj, (int)DAC_RANGE); // Max value
  52. } else {
  53. dac_write(obj, (int)(value * (float)DAC_RANGE));
  54. }
  55. }
  56. void analogout_write_u16(dac_t *obj, uint16_t value)
  57. {
  58. dac_write(obj, value >> (16 - DAC_NB_BITS));
  59. }
  60. float analogout_read(dac_t *obj)
  61. {
  62. uint32_t value = dac_read(obj);
  63. return (float)value * (1.0f / (float)DAC_RANGE);
  64. }
  65. uint16_t analogout_read_u16(dac_t *obj)
  66. {
  67. uint32_t value = dac_read(obj);
  68. return (value << 4) | ((value >> 8) & 0x000F); // Conversion from 12 to 16 bits
  69. }
  70. #endif // DEVICE_ANALOGOUT