'MAX127 Demo
func main()
    dim ch0 as float
    dim ch1 as float

    const sda 0
    const scl 1


loop:

    ch0 =MAX127read(sda,scl,0,0,1,1)


    print {.} "raw=", ch0,"   ",{.2} "Volts=",ch0*.00245*2
    pause 500
    goto loop



endfunc



'---------------------------------------------------------
'Read one of the channels from Max127
'  sda data pin.  Must be held high with 10k resistor
'  scl clock pin.  Must be held high with 10k resistor
'  addr must mach A0,A1,A2 pins (0-7)
'  chnl Max127 channel (0-7)
'  rng 0=5v  1=10v
'  bip 0=Unipolar  1-Bipolar
'
'  Returns value as float 0-4095 uniploar  -2047 - 2047 Bipolar
'---------------------------------------------------------
func MAX127read(sda,scl,addr,chnl,rng,bip) as float
  dim value
  dim control
  addr = 80 + addr
  control=chnl & 7 * 16
  control.bit(7)=1
  control.bit(3)=rng
  control.bit(2)=bip

'-----------------------------------------
'Set up control byte
'-----------------------------------------
  addr.bit(0)=0
  I2c_start(sda,scl)

  'address
  I2c_sendbyte(sda,scl,addr) 'EEprom write
  I2c_getack(sda,scl)

  'control
  I2c_sendbyte(sda,scl,control.byte(0))
  I2c_getack(sda,scl)

  I2c_stop(sda,scl)

  pauseus 25

'----------------------------------------
'Go read the conversion
'----------------------------------------
  addr.bit(0)=1
  I2c_start(sda,scl)

  'address byte
  I2c_sendbyte(sda,scl,addr)
  I2c_getack(sda,scl)

  value.byte(1) = I2c_getbyte(sda,scl)
  I2c_sendack(sda,scl)
  value.byte(0) = I2c_getbyte(sda,scl)
  I2c_sendnack(sda,scl)

  I2c_stop(sda,scl)

  value = value / 16
 
  if value.bit(11) = 1 and bip = 1 then
    value = value -1 ^ 4095 
    exit  value * -1 
  else
    exit value
  endif

endfunc


include \lib\DiosI2c.lib