Neil Thiessen / MCP4725

A feature complete driver for the MCP4725 DAC from Microchip with an AnalogOut-compatible API.

Dependents:   MCP4725_HelloWorld DAC02_RFID_and_TFT

MCP4725.h@2:42d9d780813b, 2014-05-30 (annotated)

Committer:
neilt6
Date:
Fri May 30 18:57:36 2014 +0000
Revision:
2:42d9d780813b
Parent:
1:3b687a9acdf3 
Added MBED_OPERATORS check to implementation

Who changed what in which revision?

UserRevisionLine numberNew contents of line
neilt6 0:203cdd3b30fc 1 /* MCP4725 Driver Library
neilt6 0:203cdd3b30fc 2 * Copyright (c) 2014 Neil Thiessen
neilt6 0:203cdd3b30fc 3 *
neilt6 0:203cdd3b30fc 4 * Licensed under the Apache License, Version 2.0 (the "License");
neilt6 0:203cdd3b30fc 5 * you may not use this file except in compliance with the License.
neilt6 0:203cdd3b30fc 6 * You may obtain a copy of the License at
neilt6 0:203cdd3b30fc 7 *
neilt6 0:203cdd3b30fc 8 * http://www.apache.org/licenses/LICENSE-2.0
neilt6 0:203cdd3b30fc 9 *
neilt6 0:203cdd3b30fc 10 * Unless required by applicable law or agreed to in writing, software
neilt6 0:203cdd3b30fc 11 * distributed under the License is distributed on an "AS IS" BASIS,
neilt6 0:203cdd3b30fc 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
neilt6 0:203cdd3b30fc 13 * See the License for the specific language governing permissions and
neilt6 0:203cdd3b30fc 14 * limitations under the License.
neilt6 0:203cdd3b30fc 15 */
neilt6 0:203cdd3b30fc 16
neilt6 0:203cdd3b30fc 17 #ifndef MCP4725_H
neilt6 0:203cdd3b30fc 18 #define MCP4725_H
neilt6 0:203cdd3b30fc 19
neilt6 0:203cdd3b30fc 20 #include "mbed.h"
neilt6 0:203cdd3b30fc 21
neilt6 0:203cdd3b30fc 22 /** MCP4725 class.
neilt6 0:203cdd3b30fc 23 * Used for controlling an MCP4725 DAC connected via I2C.
neilt6 0:203cdd3b30fc 24 *
neilt6 0:203cdd3b30fc 25 * Example:
neilt6 0:203cdd3b30fc 26 * @code
neilt6 0:203cdd3b30fc 27 * #include "mbed.h"
neilt6 0:203cdd3b30fc 28 * #include "MCP4725.h"
neilt6 0:203cdd3b30fc 29 *
neilt6 0:203cdd3b30fc 30 * //Create an MCP4725 object at the default address (ADDRESS_0)
neilt6 0:203cdd3b30fc 31 * MCP4725 dac(p28, p27);
neilt6 0:203cdd3b30fc 32 *
neilt6 0:203cdd3b30fc 33 * int main()
neilt6 0:203cdd3b30fc 34 * {
neilt6 0:203cdd3b30fc 35 * //Try to open the MCP4725
neilt6 0:203cdd3b30fc 36 * if (dac.open()) {
neilt6 0:203cdd3b30fc 37 * printf("Device detected!\n");
neilt6 0:203cdd3b30fc 38 *
neilt6 0:203cdd3b30fc 39 * //Wake up the DAC
neilt6 0:203cdd3b30fc 40 * //NOTE: This might wake up other I2C devices as well!
neilt6 0:203cdd3b30fc 41 * dac.wakeup();
neilt6 0:203cdd3b30fc 42 *
neilt6 0:203cdd3b30fc 43 * while (1) {
neilt6 0:203cdd3b30fc 44 * //Generate a sine wave on the DAC
neilt6 0:203cdd3b30fc 45 * for (float i = 0.0; i < 360.0; i += 0.1)
neilt6 0:203cdd3b30fc 46 * dac = 0.5 * (sinf(i * 3.14159265 / 180.0) + 1);
neilt6 0:203cdd3b30fc 47 * }
neilt6 0:203cdd3b30fc 48 * } else {
neilt6 0:203cdd3b30fc 49 * error("Device not detected!\n");
neilt6 0:203cdd3b30fc 50 * }
neilt6 0:203cdd3b30fc 51 * }
neilt6 0:203cdd3b30fc 52 * @endcode
neilt6 0:203cdd3b30fc 53 */
neilt6 0:203cdd3b30fc 54 class MCP4725
neilt6 0:203cdd3b30fc 55 {
neilt6 0:203cdd3b30fc 56 public:
neilt6 0:203cdd3b30fc 57 /** Represents the different I2C address possibilities for the MCP4725
neilt6 0:203cdd3b30fc 58 */
neilt6 0:203cdd3b30fc 59 enum Address {
neilt6 0:203cdd3b30fc 60 ADDRESS_0 = (0x60 << 1), /**< A[2:0] bits = 000 */
neilt6 0:203cdd3b30fc 61 ADDRESS_1 = (0x61 << 1), /**< A[2:0] bits = 001 */
neilt6 0:203cdd3b30fc 62 ADDRESS_2 = (0x62 << 1), /**< A[2:0] bits = 010 */
neilt6 0:203cdd3b30fc 63 ADDRESS_3 = (0x63 << 1), /**< A[2:0] bits = 011 */
neilt6 0:203cdd3b30fc 64 ADDRESS_4 = (0x64 << 1), /**< A[2:0] bits = 100 */
neilt6 0:203cdd3b30fc 65 ADDRESS_5 = (0x65 << 1), /**< A[2:0] bits = 101 */
neilt6 0:203cdd3b30fc 66 ADDRESS_6 = (0x67 << 1), /**< A[2:0] bits = 110 */
neilt6 0:203cdd3b30fc 67 ADDRESS_7 = (0x68 << 1) /**< A[2:0] bits = 111 */
neilt6 0:203cdd3b30fc 68 };
neilt6 0:203cdd3b30fc 69
neilt6 0:203cdd3b30fc 70 /** Represents the power mode of the MCP4725
neilt6 0:203cdd3b30fc 71 */
neilt6 0:203cdd3b30fc 72 enum PowerMode {
neilt6 0:203cdd3b30fc 73 POWER_NORMAL, /**< Chip is enabled, and the output is active */
neilt6 0:203cdd3b30fc 74 POWER_SHUTDOWN_1K, /**< Chip is shutdown, and the output is grounded with a 1kΩ resistor */
neilt6 0:203cdd3b30fc 75 POWER_SHUTDOWN_100K, /**< Chip is shutdown, and the output is grounded with a 100kΩ resistor */
neilt6 0:203cdd3b30fc 76 POWER_SHUTDOWN_500K /**< Chip is shutdown, and the output is grounded with a 500kΩ resistor */
neilt6 0:203cdd3b30fc 77 };
neilt6 0:203cdd3b30fc 78
neilt6 0:203cdd3b30fc 79 /** Create an MCP4725 object connected to the specified I2C pins with the specified I2C slave address
neilt6 0:203cdd3b30fc 80 *
neilt6 0:203cdd3b30fc 81 * @param sda The I2C data pin.
neilt6 0:203cdd3b30fc 82 * @param scl The I2C clock pin.
neilt6 0:203cdd3b30fc 83 * @param addr The I2C slave address (defaults to ADDRESS_0).
neilt6 0:203cdd3b30fc 84 * @param hz The I2C bus frequency (defaults to 400kHz).
neilt6 0:203cdd3b30fc 85 */
neilt6 0:203cdd3b30fc 86 MCP4725(PinName sda, PinName scl, Address addr = ADDRESS_0, int hz = 400000);
neilt6 0:203cdd3b30fc 87
neilt6 0:203cdd3b30fc 88 /** Probe for the MCP4725 and indicate if it's present on the bus
neilt6 0:203cdd3b30fc 89 *
neilt6 0:203cdd3b30fc 90 * @returns
neilt6 0:203cdd3b30fc 91 * 'true' if the device exists on the bus,
neilt6 0:203cdd3b30fc 92 * 'false' if the device doesn't exist on the bus.
neilt6 0:203cdd3b30fc 93 */
neilt6 0:203cdd3b30fc 94 bool open();
neilt6 0:203cdd3b30fc 95
neilt6 0:203cdd3b30fc 96 /** Issue a General Call Reset command to reset all MCP4725 devices on the bus
neilt6 0:203cdd3b30fc 97 *
neilt6 0:203cdd3b30fc 98 * @warning This might reset other I2C devices as well
neilt6 0:203cdd3b30fc 99 */
neilt6 0:203cdd3b30fc 100 void reset();
neilt6 0:203cdd3b30fc 101
neilt6 0:203cdd3b30fc 102 /** Issue a General Call Wake-up command to power-up all MCP4725 devices on the bus
neilt6 0:203cdd3b30fc 103 *
neilt6 0:203cdd3b30fc 104 * @warning This might wake up other I2C devices as well
neilt6 0:203cdd3b30fc 105 */
neilt6 0:203cdd3b30fc 106 void wakeup();
neilt6 0:203cdd3b30fc 107
neilt6 0:203cdd3b30fc 108 /** Get the current power mode of the MCP4725
neilt6 0:203cdd3b30fc 109 *
neilt6 0:203cdd3b30fc 110 * @returns The current power mode as a PowerMode enum.
neilt6 0:203cdd3b30fc 111 */
neilt6 0:203cdd3b30fc 112 MCP4725::PowerMode powerMode();
neilt6 0:203cdd3b30fc 113
neilt6 0:203cdd3b30fc 114 /** Set the power mode of the MCP4725
neilt6 0:203cdd3b30fc 115 *
neilt6 0:203cdd3b30fc 116 * @param mode The new power mode as a PowerMode enum.
neilt6 0:203cdd3b30fc 117 */
neilt6 0:203cdd3b30fc 118 void powerMode(PowerMode mode);
neilt6 0:203cdd3b30fc 119
neilt6 0:203cdd3b30fc 120 /** Get the current output voltage of the MCP4725 as a percentage
neilt6 0:203cdd3b30fc 121 *
neilt6 0:203cdd3b30fc 122 * @returns The current output voltage as a percentage (0.0 to 1.0 * VDD).
neilt6 0:203cdd3b30fc 123 */
neilt6 0:203cdd3b30fc 124 float read();
neilt6 0:203cdd3b30fc 125
neilt6 0:203cdd3b30fc 126 /** Set the output voltage of the MCP4725 from a percentage
neilt6 0:203cdd3b30fc 127 *
neilt6 0:203cdd3b30fc 128 * @param value The new output voltage as a percentage (0.0 to 1.0 * VDD).
neilt6 0:203cdd3b30fc 129 */
neilt6 0:203cdd3b30fc 130 void write(float value);
neilt6 0:203cdd3b30fc 131
neilt6 0:203cdd3b30fc 132 /** Set the output voltage of the MCP4725 from a 16-bit range
neilt6 0:203cdd3b30fc 133 *
neilt6 1:3b687a9acdf3 134 * @param value The new output voltage as a 16-bit unsigned short (0x0000 to 0xFFFF).
neilt6 0:203cdd3b30fc 135 */
neilt6 0:203cdd3b30fc 136 void write_u16(unsigned short value);
neilt6 0:203cdd3b30fc 137
neilt6 0:203cdd3b30fc 138 /** Get the current DAC settings in EEPROM
neilt6 0:203cdd3b30fc 139 *
neilt6 0:203cdd3b30fc 140 * @param mode Pointer to a PowerMode enum for the power mode in EEPROM.
neilt6 0:203cdd3b30fc 141 * @param value Pointer to an unsigned short for the 12-bit DAC value in EEPROM (0x0000 to 0x0FFF).
neilt6 0:203cdd3b30fc 142 */
neilt6 0:203cdd3b30fc 143 void readEeprom(PowerMode* mode, unsigned short* value);
neilt6 0:203cdd3b30fc 144
neilt6 0:203cdd3b30fc 145 /** Set the DAC settings in EEPROM
neilt6 0:203cdd3b30fc 146 *
neilt6 0:203cdd3b30fc 147 * @param mode The new EEPROM power mode as a PowerMode enum.
neilt6 0:203cdd3b30fc 148 * @param value The new EEPROM DAC value as a 12-bit unsigned short (0x0000 to 0x0FFF).
neilt6 0:203cdd3b30fc 149 */
neilt6 0:203cdd3b30fc 150 void writeEeprom(PowerMode mode, unsigned short value);
neilt6 0:203cdd3b30fc 151
neilt6 0:203cdd3b30fc 152 #ifdef MBED_OPERATORS
neilt6 0:203cdd3b30fc 153 /** A shorthand for read()
neilt6 0:203cdd3b30fc 154 *
neilt6 0:203cdd3b30fc 155 * @returns The current output voltage as a percentage (0.0 to 1.0 * VDD).
neilt6 0:203cdd3b30fc 156 */
neilt6 0:203cdd3b30fc 157 operator float();
neilt6 0:203cdd3b30fc 158
neilt6 0:203cdd3b30fc 159 /** A shorthand for write()
neilt6 0:203cdd3b30fc 160 *
neilt6 0:203cdd3b30fc 161 * @param value The new output voltage as a percentage (0.0 to 1.0 * VDD).
neilt6 0:203cdd3b30fc 162 */
neilt6 0:203cdd3b30fc 163 MCP4725& operator=(float value);
neilt6 0:203cdd3b30fc 164 #endif
neilt6 0:203cdd3b30fc 165
neilt6 0:203cdd3b30fc 166 private:
neilt6 0:203cdd3b30fc 167 //Member variables
neilt6 0:203cdd3b30fc 168 I2C m_I2C;
neilt6 0:203cdd3b30fc 169 const int m_ADDR;
neilt6 0:203cdd3b30fc 170 MCP4725::PowerMode m_PowerMode;
neilt6 0:203cdd3b30fc 171 unsigned short m_DacValue;
neilt6 0:203cdd3b30fc 172
neilt6 0:203cdd3b30fc 173 //Internal functions
neilt6 0:203cdd3b30fc 174 void readDac();
neilt6 0:203cdd3b30fc 175 void writeDac();
neilt6 0:203cdd3b30fc 176 };
neilt6 0:203cdd3b30fc 177
neilt6 0:203cdd3b30fc 178 #endif