AD5258.h

00001 /*  Copyright 2013 Rod Coleman
00002 
00003     This program is free software: you can redistribute it and/or modify
00004     it under the terms of the GNU General Public License as published by
00005     the Free Software Foundation, either version 3 of the License, or
00006     (at your option) any later version.
00007 
00008     This program is distributed in the hope that it will be useful,
00009     but WITHOUT ANY WARRANTY; without even the implied warranty of
00010     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00011     GNU General Public License for more details.
00012 
00013     You should have received a copy of the GNU General Public License
00014     along with this program.  If not, see <http://www.gnu.org/licenses/>.
00015 */   
00016 
00017 #include "mbed.h"
00018  
00019 #ifndef MBED_AD5258_H
00020 #define MBED_AD5258_H
00021  
00022 // Interface to the AD5258 I2C 64-step (0x00 to 0x3F)6-Bit digital Potentiometer
00023 
00024 // measure reference voltage on the pin6 of U3 LM293
00025 // be sure to remove R11, and check R4 is 220
00026 
00027 /*Examples: RDAC =
00028 0x00, Vref=1,0V
00029 0x03, Vref=1,1V
00030 0x05, Vref=1,2V
00031 0x0F, Vref=1,5V
00032 0x20, Vref=1,82V  // default
00033 0x30, Vref=2,0V
00034 0x3F, Vref=2,2V 
00035 */
00036 
00037 
00038 class AD5258 {
00039 public:
00040     /** Create an instance of the AD5258 connected to specfied I2C pins, with the specified address.
00041      *
00042      * @param sda The I2C data pin
00043      * @param scl The I2C clock pin
00044      * @param address The I2C address for this AD5258
00045      */
00046     AD5258(PinName sda, PinName scl, int address);
00047  
00048     /** Read the RDAC value
00049      *
00050      * @return The 6-bit value read
00051      */
00052     int read();
00053     
00054     /** Write to the RDAC
00055      * 
00056      * @param data The 6-bits value: 0x00 to 0x3F to write to the pots RDAC
00057      */
00058     void write(int data);
00059     
00060     // READ and WRITE EEPROM
00061     
00062         /** Read the EEPROM value
00063      *
00064      * @return The 6-bit value read
00065      */
00066     int readEE();
00067     
00068       /** Write to the RDAC
00069      * 
00070      * @param data The 6-bits value: 0x00 to 0x3F to write to the pots RDAC
00071      */
00072     void writeEE(int data); 
00073     
00074     
00075     
00076     
00077     // STORE and RESTORE:
00078     
00079     /** store the RDAC value into the EEPROM, for nonvolatile keeping of the value
00080     *
00081     */
00082     void store(void);
00083  
00084     /** restore to the RDAC the value from the EEPROM. NOP issued afterward, to put back into low-power idle mode
00085     *
00086     */
00087     void restore(void);
00088     
00089     
00090     /** update write protect bit
00091     *
00092     * @param enable: TRUE to SET WP, FALSE to lift WP
00093     */
00094  
00095     void writeProtect(bool enable);
00096  
00097     //  TODO: tolerance register access
00098  
00099  
00100  
00101 private:
00102     I2C _i2c;
00103     int _address;
00104 };
00105  
00106 #endif