Revision 0:b3b7aff20a1d, committed 2017-10-09

Comitter:

maclobdell

Date:

Mon Oct 09 12:52:15 2017 +0000

Child:

1:b2d54467330d

Commit message:

initial version, haven't tested yet

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX1704X.cpp	Mon Oct 09 12:52:15 2017 +0000
@@ -0,0 +1,168 @@
+/* MAX1704X Simple Driver Library
+ * Copyright (c) 2017 Mac Lobdell
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//todo: configure pin interrupt on battery level alert
+
+#include "MAX1704X.h"
+
+MAX1704X::MAX1704X(PinName sda, PinName scl, Address addr, int hz) : m_I2C(sda, scl), m_ADDR((int)addr)
+{
+    //Set the I2C bus frequency
+    m_I2C.frequency(hz);
+
+    write16(REG_CONFIG_H,0x9700);  //set alert to 32%
+    
+}
+
+bool MAX1704X::open()
+{
+    //Probe for the I2C Device using a Zero Length Transfer
+    if (!m_I2C.write(m_ADDR, NULL, 0)) {
+        //Return success
+        return true;
+    } else {
+        //Return failure
+        return false;
+    }
+}
+
+uint32_t MAX1704X::read_ad()
+{
+  char xm, xl;
+  uint32_t temp, xo;
+  
+  xm = read8(REG_VCELL_H);  //high byte
+  xl = read8(REG_VCELL_L);  //low byte
+  
+  temp = (xl|(xm << 8));
+  //alternatively can read16
+ //xo = read16(REG_VCELL_H);    //does this work?
+  
+  xo = 1.25* (temp >>4);
+
+  //returns A/D value in mV
+  return xo;
+  
+}
+  
+uint16_t MAX1704X::read_config()
+{
+  char xm, xl;
+  uint16_t xo;
+  
+  xm = read8(REG_CONFIG_H);   //high byte 
+  xl = read8(REG_CONFIG_L); //low byte
+
+  xo = xl|(xm << 8);
+
+  //alternatively can read16
+//  xo = read16(REG_CONFIG_H);    //does this work?
+  
+  return xo;  
+}
+
+uint32_t MAX1704X::read_percent()
+{
+  char xm, xl;
+  uint32_t xo;
+  
+  xm = read8(REG_SOC_H);  //high byte
+  xl = read8(REG_SOC_L);  //low byte
+  
+  xo = (xl|(xm << 8));
+
+  //alternatively can read16
+//  xo = read16(REG_SOC_H);    //does this work?
+
+  //percent_decimal = (0.003906)*xl + xm;
+
+  //returns percent
+  return xo;
+    
+}
+
+ void MAX1704X::power_on_reset(void)
+ {
+
+   write8(REG_COMMAND_H, 0x54);
+   write8(REG_COMMAND_L, 0x00);
+
+  //alternatively can write16
+  //write16(REG_COMMAND_H, 0x5400);  //does this work?
+  
+ }
+/*
+//#ifdef MBED_OPERATORS  //this no longer be needed? 
+MAX1704X::operator uint32_t()
+{
+    //Return the current battery percentage
+    return read_percent();
+}
+//#endif
+*/
+char MAX1704X::read8(char reg)
+{
+    //Select the register
+    m_I2C.write(m_ADDR, &reg, 1, true);
+
+    //Read the 8-bit register
+    m_I2C.read(m_ADDR, &reg, 1);
+
+    //Return the byte
+    return reg;
+}
+
+void MAX1704X::write8(char reg, char data)
+{
+    //Create a temporary buffer
+    char buff[2];
+
+    //Load the register address and 8-bit data
+    buff[0] = reg;
+    buff[1] = data;
+
+    //Write the data
+    m_I2C.write(m_ADDR, buff, 2);
+}
+
+uint16_t MAX1704X::read16(char reg)
+{
+    //Create a temporary buffer
+    char buff[2];
+
+    //Select the register
+    m_I2C.write(m_ADDR, &reg, 1, true);
+
+    //Read the 16-bit register
+    m_I2C.read(m_ADDR, buff, 2);
+
+    //Return the combined 16-bit value
+    return (buff[0] << 8) | buff[1];
+}
+
+void MAX1704X::write16(char reg, uint16_t data)
+{
+    //Create a temporary buffer
+    char buff[3];
+
+    //Load the register address and 16-bit data
+    buff[0] = reg;
+    buff[1] = data >> 8;
+    buff[2] = data;
+
+    //Write the data
+    m_I2C.write(m_ADDR, buff, 3);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX1704X.h	Mon Oct 09 12:52:15 2017 +0000
@@ -0,0 +1,139 @@
+/* MAX1704X Simple Driver Library
+ * Copyright (c) 2017 Mac Lobdell
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef MAX1704X_H
+#define MAX1704X_H
+
+#include "mbed.h"
+
+/** MAX1704X class.
+ *  Used for reading  MAX1704X lipo fuel guage connected via I2C.
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "MAX1704X.h"
+ *
+ * //Create an MAX1704X object at the default address (ADDRESS_0)
+ * MAX1704X battery_level(p28, p27);
+ *
+ * int main()
+ * {
+ *     //Try to open the MAX1704X
+ *     if (battery_level.open()) {
+ *         printf("Device detected!\n");
+ *
+ *         while (1) {
+ *             //Print the current battery level
+ *             printf("battery = %d\n", battery_level);
+ *
+ *             //Sleep for 1 seconds
+ *             wait(1);
+ *         }
+ *     } else {
+ *         error("Device not detected!\n");
+ *     }
+ * }
+ * @endcode
+ */
+class MAX1704X
+{
+public:
+    /** Represents the different I2C address possibilities for the MAX1704X
+     */
+     
+    enum Address {
+        ADDRESS_0 = (0x36 << 1)    /* Slave Address 011 0110 + r/w bit */
+    };
+
+    /** Create an MAX1704X object connected to the specified I2C pins with the specified I2C slave address
+     *
+     * @param sda The I2C data pin.
+     * @param scl The I2C clock pin.
+     * @param addr The I2C slave address (defaults to ADDRESS_0).
+     * @param hz The I2C bus frequency (defaults to 400kHz).
+     */
+    MAX1704X(PinName sda, PinName scl, Address addr = ADDRESS_0, int hz = 400000);
+
+    /** Probe for the MAX1704X and indicate if it's present on the bus
+     *
+     * @returns
+     *   'true' if the device exists on the bus,
+     *   'false' if the device doesn't exist on the bus.
+     */
+    bool open();
+
+    /** assert power on reset on MAX1704X
+     *
+     * @returns void
+     */
+     void power_on_reset(void);
+
+    /** Get the current ad of the MAX1704X
+     *
+     * @returns The current ad.
+     */
+    uint32_t read_ad();
+
+    /** Get the current config of the MAX1704X
+     *
+     * @returns The current config of the MAX170X.
+     */
+    uint16_t read_config();
+
+    /** Get the current battery charge percent from MAX1704X
+     *
+     * @returns The current battery charge percent from MAX1704X.
+     */
+    uint32_t read_percent();
+
+//#ifdef MBED_OPERATORS
+    /** A shorthand for percentage()
+     *
+     * @returns the current battery percentage measurement.
+     */
+//    operator uint32_t();
+//#endif
+
+private:
+    //I2C register addresses
+    enum Register {
+        REG_VCELL_H = 0x02,
+        REG_VCELL_L = 0x03,
+        REG_SOC_H   = 0x04,
+        REG_SOC_L   = 0x05,        
+        REG_MODE_H  = 0x06,        
+        REG_MODE_L  = 0x07,                
+        REG_VER_H   = 0x08,        
+        REG_VER_L   = 0x09,                
+        REG_CONFIG_H  = 0x0C,        
+        REG_CONFIG_L  = 0x0D,                                
+        REG_COMMAND_H  = 0xFE,        
+        REG_COMMAND_L  = 0xFF                                       
+    };
+
+    //Member variables
+    I2C m_I2C;
+    const int m_ADDR;
+    
+    //Internal functions
+    char read8(char reg);
+    void write8(char reg, char data);
+    uint16_t read16(char reg);
+    void write16(char reg, uint16_t data);
+};
+
+#endif