ltc2941.sb

//******************************************************************************
// Copyright (c) 2016, Laird
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
// IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
// SPDX-License-Identifier:ISC
//
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// +++++                                                                      ++
// +++++  When UwTerminal downloads the app it will store it as a filenname   ++
// +++++  which consists of all characters up to the first . and excluding it ++
// +++++                                                                      ++
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//
// This app monitors the LTC2941 battery gas gauge device on the RM1xx DVK using 
// the I2C bus. This device can be used to monigor current consumption by the 
// RM1xx device.
//
// Details on the reported charge register value can be found in the datasheet
// for the LTC2941.
//
//******************************************************************************

dim nLTC2941Addr
nLTC2941Addr = 0x64 //Hard-coded 7-bit I2C address 1100100

dim retVal
dim handle
dim nStatusRegVal
dim nControlRegVal
dim nChargeRegVal
dim nStatusRegAddr
dim nControlRegAddr
dim nChargeRegAddr

nStatusRegAddr  = 0x00 //8-bit status register
nControlRegAddr = 0x01 //8-bit status register
nChargeRegAddr  = 0x02 //16-bit accumulated charge

nStatusRegVal  = 0x0
nControlRegVal = 0x0
nChargeRegVal  = 0x0

function handleTimer0()
    retVal = I2CReadReg16(nLTC2941Addr, nChargeRegAddr, nChargeRegVal)
    retVal = (256*(nChargeRegVal & 0xff)+((nChargeRegVal >> 8) & 0xff))
    print"ChargeRegVal = ";retVal;"\n"
endfunc 1

onevent EvTmr0 call handleTimer0

retVal = I2COpen(400000,0,handle)
if retVal != 0 then
    print "\nFailed to open I2C interface with error code "; INTEGER.h' retVal
    waitevent
else
    print "\nI2C open success \nHandle is ";handle
endif

nControlRegVal = 0x01 //Set prescaler to 128 and disable !AL/CC pin
retVal = I2CWriteReg8(nLTC2941Addr, nControlRegAddr, nControlRegVal)
nControlRegVal = 0x38 //Set prescaler to 128 and disable !AL/CC pin
retVal = I2CWriteReg8(nLTC2941Addr, nControlRegAddr, nControlRegVal)
    
retVal = I2CReadReg8(nLTC2941Addr, nStatusRegAddr, nStatusRegVal)
print"\nStatusRegVal = ";INTEGER.H'nStatusRegVal;"\n"

retVal = I2CReadReg8(nLTC2941Addr, nControlRegAddr, nControlRegVal)
print"\nControlRegVal = ";INTEGER.H'nControlRegVal;"\n"

//Start a recurring timer to read charge values
TimerStart(0,1000,1)

waitevent
I2CClose(handle)