Mac Lobdell / MAX1704X

Library for I2C communication with LiPo battery fuel gauge to measure battery level.

Dependents:   MAX1704X_example_app

MAX1704X.cpp@0:b3b7aff20a1d, 2017-10-09 (annotated)

Committer:
maclobdell
Date:
Mon Oct 09 12:52:15 2017 +0000
Revision:
0:b3b7aff20a1d
Child:
1:b2d54467330d
initial version, haven't tested yet

Who changed what in which revision?

UserRevisionLine numberNew contents of line
maclobdell 0:b3b7aff20a1d 1 /* MAX1704X Simple Driver Library
maclobdell 0:b3b7aff20a1d 2 * Copyright (c) 2017 Mac Lobdell
maclobdell 0:b3b7aff20a1d 3 *
maclobdell 0:b3b7aff20a1d 4 * Licensed under the Apache License, Version 2.0 (the "License");
maclobdell 0:b3b7aff20a1d 5 * you may not use this file except in compliance with the License.
maclobdell 0:b3b7aff20a1d 6 * You may obtain a copy of the License at
maclobdell 0:b3b7aff20a1d 7 *
maclobdell 0:b3b7aff20a1d 8 * http://www.apache.org/licenses/LICENSE-2.0
maclobdell 0:b3b7aff20a1d 9 *
maclobdell 0:b3b7aff20a1d 10 * Unless required by applicable law or agreed to in writing, software
maclobdell 0:b3b7aff20a1d 11 * distributed under the License is distributed on an "AS IS" BASIS,
maclobdell 0:b3b7aff20a1d 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
maclobdell 0:b3b7aff20a1d 13 * See the License for the specific language governing permissions and
maclobdell 0:b3b7aff20a1d 14 * limitations under the License.
maclobdell 0:b3b7aff20a1d 15 */
maclobdell 0:b3b7aff20a1d 16
maclobdell 0:b3b7aff20a1d 17 //todo: configure pin interrupt on battery level alert
maclobdell 0:b3b7aff20a1d 18
maclobdell 0:b3b7aff20a1d 19 #include "MAX1704X.h"
maclobdell 0:b3b7aff20a1d 20
maclobdell 0:b3b7aff20a1d 21 MAX1704X::MAX1704X(PinName sda, PinName scl, Address addr, int hz) : m_I2C(sda, scl), m_ADDR((int)addr)
maclobdell 0:b3b7aff20a1d 22 {
maclobdell 0:b3b7aff20a1d 23 //Set the I2C bus frequency
maclobdell 0:b3b7aff20a1d 24 m_I2C.frequency(hz);
maclobdell 0:b3b7aff20a1d 25
maclobdell 0:b3b7aff20a1d 26 write16(REG_CONFIG_H,0x9700); //set alert to 32%
maclobdell 0:b3b7aff20a1d 27
maclobdell 0:b3b7aff20a1d 28 }
maclobdell 0:b3b7aff20a1d 29
maclobdell 0:b3b7aff20a1d 30 bool MAX1704X::open()
maclobdell 0:b3b7aff20a1d 31 {
maclobdell 0:b3b7aff20a1d 32 //Probe for the I2C Device using a Zero Length Transfer
maclobdell 0:b3b7aff20a1d 33 if (!m_I2C.write(m_ADDR, NULL, 0)) {
maclobdell 0:b3b7aff20a1d 34 //Return success
maclobdell 0:b3b7aff20a1d 35 return true;
maclobdell 0:b3b7aff20a1d 36 } else {
maclobdell 0:b3b7aff20a1d 37 //Return failure
maclobdell 0:b3b7aff20a1d 38 return false;
maclobdell 0:b3b7aff20a1d 39 }
maclobdell 0:b3b7aff20a1d 40 }
maclobdell 0:b3b7aff20a1d 41
maclobdell 0:b3b7aff20a1d 42 uint32_t MAX1704X::read_ad()
maclobdell 0:b3b7aff20a1d 43 {
maclobdell 0:b3b7aff20a1d 44 char xm, xl;
maclobdell 0:b3b7aff20a1d 45 uint32_t temp, xo;
maclobdell 0:b3b7aff20a1d 46
maclobdell 0:b3b7aff20a1d 47 xm = read8(REG_VCELL_H); //high byte
maclobdell 0:b3b7aff20a1d 48 xl = read8(REG_VCELL_L); //low byte
maclobdell 0:b3b7aff20a1d 49
maclobdell 0:b3b7aff20a1d 50 temp = (xl|(xm << 8));
maclobdell 0:b3b7aff20a1d 51 //alternatively can read16
maclobdell 0:b3b7aff20a1d 52 //xo = read16(REG_VCELL_H); //does this work?
maclobdell 0:b3b7aff20a1d 53
maclobdell 0:b3b7aff20a1d 54 xo = 1.25* (temp >>4);
maclobdell 0:b3b7aff20a1d 55
maclobdell 0:b3b7aff20a1d 56 //returns A/D value in mV
maclobdell 0:b3b7aff20a1d 57 return xo;
maclobdell 0:b3b7aff20a1d 58
maclobdell 0:b3b7aff20a1d 59 }
maclobdell 0:b3b7aff20a1d 60
maclobdell 0:b3b7aff20a1d 61 uint16_t MAX1704X::read_config()
maclobdell 0:b3b7aff20a1d 62 {
maclobdell 0:b3b7aff20a1d 63 char xm, xl;
maclobdell 0:b3b7aff20a1d 64 uint16_t xo;
maclobdell 0:b3b7aff20a1d 65
maclobdell 0:b3b7aff20a1d 66 xm = read8(REG_CONFIG_H); //high byte
maclobdell 0:b3b7aff20a1d 67 xl = read8(REG_CONFIG_L); //low byte
maclobdell 0:b3b7aff20a1d 68
maclobdell 0:b3b7aff20a1d 69 xo = xl|(xm << 8);
maclobdell 0:b3b7aff20a1d 70
maclobdell 0:b3b7aff20a1d 71 //alternatively can read16
maclobdell 0:b3b7aff20a1d 72 // xo = read16(REG_CONFIG_H); //does this work?
maclobdell 0:b3b7aff20a1d 73
maclobdell 0:b3b7aff20a1d 74 return xo;
maclobdell 0:b3b7aff20a1d 75 }
maclobdell 0:b3b7aff20a1d 76
maclobdell 0:b3b7aff20a1d 77 uint32_t MAX1704X::read_percent()
maclobdell 0:b3b7aff20a1d 78 {
maclobdell 0:b3b7aff20a1d 79 char xm, xl;
maclobdell 0:b3b7aff20a1d 80 uint32_t xo;
maclobdell 0:b3b7aff20a1d 81
maclobdell 0:b3b7aff20a1d 82 xm = read8(REG_SOC_H); //high byte
maclobdell 0:b3b7aff20a1d 83 xl = read8(REG_SOC_L); //low byte
maclobdell 0:b3b7aff20a1d 84
maclobdell 0:b3b7aff20a1d 85 xo = (xl|(xm << 8));
maclobdell 0:b3b7aff20a1d 86
maclobdell 0:b3b7aff20a1d 87 //alternatively can read16
maclobdell 0:b3b7aff20a1d 88 // xo = read16(REG_SOC_H); //does this work?
maclobdell 0:b3b7aff20a1d 89
maclobdell 0:b3b7aff20a1d 90 //percent_decimal = (0.003906)*xl + xm;
maclobdell 0:b3b7aff20a1d 91
maclobdell 0:b3b7aff20a1d 92 //returns percent
maclobdell 0:b3b7aff20a1d 93 return xo;
maclobdell 0:b3b7aff20a1d 94
maclobdell 0:b3b7aff20a1d 95 }
maclobdell 0:b3b7aff20a1d 96
maclobdell 0:b3b7aff20a1d 97 void MAX1704X::power_on_reset(void)
maclobdell 0:b3b7aff20a1d 98 {
maclobdell 0:b3b7aff20a1d 99
maclobdell 0:b3b7aff20a1d 100 write8(REG_COMMAND_H, 0x54);
maclobdell 0:b3b7aff20a1d 101 write8(REG_COMMAND_L, 0x00);
maclobdell 0:b3b7aff20a1d 102
maclobdell 0:b3b7aff20a1d 103 //alternatively can write16
maclobdell 0:b3b7aff20a1d 104 //write16(REG_COMMAND_H, 0x5400); //does this work?
maclobdell 0:b3b7aff20a1d 105
maclobdell 0:b3b7aff20a1d 106 }
maclobdell 0:b3b7aff20a1d 107 /*
maclobdell 0:b3b7aff20a1d 108 //#ifdef MBED_OPERATORS //this no longer be needed?
maclobdell 0:b3b7aff20a1d 109 MAX1704X::operator uint32_t()
maclobdell 0:b3b7aff20a1d 110 {
maclobdell 0:b3b7aff20a1d 111 //Return the current battery percentage
maclobdell 0:b3b7aff20a1d 112 return read_percent();
maclobdell 0:b3b7aff20a1d 113 }
maclobdell 0:b3b7aff20a1d 114 //#endif
maclobdell 0:b3b7aff20a1d 115 */
maclobdell 0:b3b7aff20a1d 116 char MAX1704X::read8(char reg)
maclobdell 0:b3b7aff20a1d 117 {
maclobdell 0:b3b7aff20a1d 118 //Select the register
maclobdell 0:b3b7aff20a1d 119 m_I2C.write(m_ADDR, &reg, 1, true);
maclobdell 0:b3b7aff20a1d 120
maclobdell 0:b3b7aff20a1d 121 //Read the 8-bit register
maclobdell 0:b3b7aff20a1d 122 m_I2C.read(m_ADDR, &reg, 1);
maclobdell 0:b3b7aff20a1d 123
maclobdell 0:b3b7aff20a1d 124 //Return the byte
maclobdell 0:b3b7aff20a1d 125 return reg;
maclobdell 0:b3b7aff20a1d 126 }
maclobdell 0:b3b7aff20a1d 127
maclobdell 0:b3b7aff20a1d 128 void MAX1704X::write8(char reg, char data)
maclobdell 0:b3b7aff20a1d 129 {
maclobdell 0:b3b7aff20a1d 130 //Create a temporary buffer
maclobdell 0:b3b7aff20a1d 131 char buff[2];
maclobdell 0:b3b7aff20a1d 132
maclobdell 0:b3b7aff20a1d 133 //Load the register address and 8-bit data
maclobdell 0:b3b7aff20a1d 134 buff[0] = reg;
maclobdell 0:b3b7aff20a1d 135 buff[1] = data;
maclobdell 0:b3b7aff20a1d 136
maclobdell 0:b3b7aff20a1d 137 //Write the data
maclobdell 0:b3b7aff20a1d 138 m_I2C.write(m_ADDR, buff, 2);
maclobdell 0:b3b7aff20a1d 139 }
maclobdell 0:b3b7aff20a1d 140
maclobdell 0:b3b7aff20a1d 141 uint16_t MAX1704X::read16(char reg)
maclobdell 0:b3b7aff20a1d 142 {
maclobdell 0:b3b7aff20a1d 143 //Create a temporary buffer
maclobdell 0:b3b7aff20a1d 144 char buff[2];
maclobdell 0:b3b7aff20a1d 145
maclobdell 0:b3b7aff20a1d 146 //Select the register
maclobdell 0:b3b7aff20a1d 147 m_I2C.write(m_ADDR, &reg, 1, true);
maclobdell 0:b3b7aff20a1d 148
maclobdell 0:b3b7aff20a1d 149 //Read the 16-bit register
maclobdell 0:b3b7aff20a1d 150 m_I2C.read(m_ADDR, buff, 2);
maclobdell 0:b3b7aff20a1d 151
maclobdell 0:b3b7aff20a1d 152 //Return the combined 16-bit value
maclobdell 0:b3b7aff20a1d 153 return (buff[0] << 8) | buff[1];
maclobdell 0:b3b7aff20a1d 154 }
maclobdell 0:b3b7aff20a1d 155
maclobdell 0:b3b7aff20a1d 156 void MAX1704X::write16(char reg, uint16_t data)
maclobdell 0:b3b7aff20a1d 157 {
maclobdell 0:b3b7aff20a1d 158 //Create a temporary buffer
maclobdell 0:b3b7aff20a1d 159 char buff[3];
maclobdell 0:b3b7aff20a1d 160
maclobdell 0:b3b7aff20a1d 161 //Load the register address and 16-bit data
maclobdell 0:b3b7aff20a1d 162 buff[0] = reg;
maclobdell 0:b3b7aff20a1d 163 buff[1] = data >> 8;
maclobdell 0:b3b7aff20a1d 164 buff[2] = data;
maclobdell 0:b3b7aff20a1d 165
maclobdell 0:b3b7aff20a1d 166 //Write the data
maclobdell 0:b3b7aff20a1d 167 m_I2C.write(m_ADDR, buff, 3);
maclobdell 0:b3b7aff20a1d 168 }