'co @lizby
'OPTION EXPLICIT
'OPTION DEFAULT NONE
' MCP23017.bas I2C test

const mcp23017 = &h20 ' A2, A1, A0, R/W all connected to 0V
Const i2caddr=mcp23017
const IODIRA = &h00 ' Port A IO Direction register DEFAULT = I/P
const IODIRB = &h01 ' Port B IO Direction register DEFAULT = I/P
const IOCON = &h0A ' IO Expander config register - address &h0B accesses  same register
const GPIOA = &h12 ' Port A General purpose register
const GPIOB = &h13 ' Port B General Purpose register
const OLATA = &h14 ' Port A latch register
const OLATB = &h15 ' Port B latch register
const GPUPA = &h0C ' Port C pull-up register
const GPUPB = &h0D ' Port B pull-up register
I2C WRITE MCP23017,0,2,IODIRA,0 ' set direction to output
I2C WRITE MCP23017,0,2,IODIRB,0 ' set direction to output
do
mcp17
loop
sub mcp17
for i = 1 to 6
  I2C Write MCP23017,0,2,OLATA,&b10101010 '  
  I2C Write MCP23017,0,2,OLATB,&b01010101 '  
  PAUSE     1000
  I2C Write MCP23017,0,2,OLATA,&b01010101 '  
  I2C Write MCP23017,0,2,OLATB,&b10101010 '  
  PAUSE     1000
Next i
I2C Write MCP23017,0,2,OLATA,0 ' turn all off
I2C Write MCP23017,0,2,OLATB,0 ' turn all off
pause 1000
end sub