MAX1704X.h

00001 /* MAX1704X Simple Driver Library
00002  * Copyright (c) 2017 Mac Lobdell
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef MAX1704X_H
00018 #define MAX1704X_H
00019 
00020 #include "mbed.h"
00021 
00022 /** MAX1704X class.
00023  *  Used for reading  MAX1704X lipo fuel guage connected via I2C.
00024  *
00025  * Example:
00026  * @code
00027  * #include "mbed.h"
00028  * #include "MAX1704X.h"
00029  *
00030  * //Create an MAX1704X object at the default address (ADDRESS_0)
00031  * MAX1704X battery_level(p28, p27);
00032  *
00033  * int main()
00034  * {
00035  *     //Try to open the MAX1704X
00036  *     if (battery_level.open()) {
00037  *         printf("Device detected!\n");
00038  *
00039  *         while (1) {
00040  *             //Print the current battery level
00041  *             printf("battery = %d\n", battery_level);
00042  *
00043  *             //Sleep for 1 seconds
00044  *             wait(1);
00045  *         }
00046  *     } else {
00047  *         error("Device not detected!\n");
00048  *     }
00049  * }
00050  * @endcode
00051  */
00052 class MAX1704X
00053 {
00054 public:
00055     /** Represents the different I2C address possibilities for the MAX1704X
00056      */
00057      
00058     enum Address {
00059         ADDRESS_0 = (0x36 << 1)    /* Slave Address 011 0110 + r/w bit */
00060     };
00061 
00062     /** Create an MAX1704X object connected to the specified I2C pins with the specified I2C slave address
00063      *
00064      * @param sda The I2C data pin.
00065      * @param scl The I2C clock pin.
00066      * @param addr The I2C slave address (defaults to ADDRESS_0).
00067      * @param hz The I2C bus frequency (defaults to 400kHz).
00068      */
00069     MAX1704X(PinName sda, PinName scl, Address addr = ADDRESS_0, int hz = 400000);
00070 
00071     /** Probe for the MAX1704X and indicate if it's present on the bus
00072      *
00073      * @returns
00074      *   'true' if the device exists on the bus,
00075      *   'false' if the device doesn't exist on the bus.
00076      */
00077     bool open();
00078 
00079     /** assert power on reset on MAX1704X
00080      *
00081      * @returns void
00082      */
00083      void power_on_reset(void);
00084 
00085     /** Get the current ad of the MAX1704X
00086      *
00087      * @returns The current ad.
00088      */
00089     uint32_t read_ad();
00090 
00091     /** Get the current config of the MAX1704X
00092      *
00093      * @returns The current config of the MAX170X.
00094      */
00095     uint16_t read_config();
00096 
00097     /** Get the current battery charge percent from MAX1704X
00098      *
00099      * @returns The current battery charge percent from MAX1704X.
00100      */
00101     uint32_t read_percent();
00102 
00103 //#ifdef MBED_OPERATORS
00104     /** A shorthand for percentage()
00105      *
00106      * @returns the current battery percentage measurement.
00107      */
00108 //    operator uint32_t();
00109 //#endif
00110 
00111 private:
00112     //I2C register addresses
00113     enum Register {
00114         REG_VCELL_H = 0x02,
00115         REG_VCELL_L = 0x03,
00116         REG_SOC_H   = 0x04,
00117         REG_SOC_L   = 0x05,        
00118         REG_MODE_H  = 0x06,        
00119         REG_MODE_L  = 0x07,                
00120         REG_VER_H   = 0x08,        
00121         REG_VER_L   = 0x09,                
00122         REG_CONFIG_H  = 0x0C,        
00123         REG_CONFIG_L  = 0x0D,                                
00124         REG_COMMAND_H  = 0xFE,        
00125         REG_COMMAND_L  = 0xFF                                       
00126     };
00127 
00128     //Member variables
00129     I2C m_I2C;
00130     const int m_ADDR;
00131     
00132     //Internal functions
00133     char read8(char reg);
00134     void write8(char reg, char data);
00135     uint16_t read16(char reg);
00136     void write16(char reg, uint16_t data);
00137 };
00138 
00139 #endif