-- John Longworth December 2017
-- Reads data from EEPROM
-- Uses I2C module

local id, sda, scl, device = 0, 3, 4, 0x50
i2c.setup(id, sda, scl, i2c.SLOW)  -- Initialise I2C 

function ReadEE(memloc, length)   -- Read data from EEPROM
    addrh=bit.rshift(memloc, 8)
    addrl=bit.band(memloc,0xff)
    print(adrh, adrl, length)
    i2c.start(id)
    i2c.address(id, device, i2c.TRANSMITTER)
    i2c.write(id, addrh)
    i2c.write(id, addrl)
    i2c.stop(id)
    i2c.start(id)
    i2c.address(id, device, i2c.RECEIVER)
    c = i2c.read(id, length)
    i2c.stop(id)
    return  c
end   

print(ReadEE(0,286)) -- Read 286 bytes of data

-- 24C256 wiring
-- A1,A2,NC,WP,Gnd connect to Gnd
-- Vcc connect to 3.3v
-- SDA & SCL connect to 3.3v through a 10k resistor
-- SDA connect to pin 3 GPIO0
-- SCL connect to pin 4 GPIO2
-- Memory range 0000h - 7FFFh