-- Kitt Car Modified by John Longworth December 2017
-- Using pins 3 & 4 to be compatible with ESP001
-- SDA & SDL can be assigned any pin number between 1 - 12
-- Connects to MCP23008 (8-Bit I/O Expander with Serial Interface)
-- Uses mcp23008.lua - This file must be in the ESP8266 memory

local i = 1
local dir = 1
mcp = require ("mcp23008")
id = 0x00  -- Always 0
sda = 3  -- GPIO0 Connect to Pin 2 of MCP23008 
scl = 4  -- GPIO2 Connect to Pin 1 of MCP23008 

mcp.begin(id,sda,scl,i2c.SLOW)
mcp.writeIODIR(0x00)  -- Set all GPIO pins as outputs

tmr.alarm(1,250,1,function() 
    print("I = " .. i)
    mcp.writeGPIO(i)    
    dir = (i == 1) and (dir == -1) and 1 or (i == 128) and (dir == 1) and -1 or dir
    i = (dir == 1) and i * 2 or i / 2
end)