47 lines
1.5 KiB
Lua
47 lines
1.5 KiB
Lua
---
|
|
-- @description Shows control of 8 GPIO pins/LEDs via I2C with the MCP23008 I/O expander.
|
|
-- Tested on odeMCU 0.9.5 build 20150213.
|
|
-- @date March 02, 2015
|
|
-- @circuit Connect 8 LEDs withs resistors to the GPIO pins of the MCP23008.
|
|
-- Connect GPIO0 of the ESP8266-01 module to the SCL pin of the MCP23008.
|
|
-- Connect GPIO2 of the ESP8266-01 module to the SDA pin of the MCP23008.
|
|
-- Connect two 4.7k pull-up resistors on SDA and SCL
|
|
-- Use 3.3V for VCC.
|
|
-- @author Miguel (AllAboutEE)
|
|
-- GitHub: https://github.com/AllAboutEE
|
|
-- Working Example Video: https://www.youtube.com/watch?v=KphAJMZZed0
|
|
-- Website: http://AllAboutEE.com
|
|
---------------------------------------------------------------------------------------------
|
|
|
|
local mcp23008 = require ("mcp23008")
|
|
|
|
-- ESP-01 GPIO Mapping as per GPIO Table in https://github.com/nodemcu/nodemcu-firmware
|
|
local gpio0, gpio2 = 3, 4
|
|
|
|
---
|
|
-- @name count()
|
|
-- @description Reads the value from the GPIO register, increases the read value by 1
|
|
-- and writes it back so the LEDs will display a binary count up to 255 or 0xFF in hex.
|
|
local function count()
|
|
local gpio = mcp23008.readGPIO()
|
|
|
|
if(gpio<0xff) then
|
|
mcp23008.writeGPIO(gpio+1)
|
|
else
|
|
mcp23008.writeGPIO(0x00)
|
|
end
|
|
|
|
end
|
|
|
|
do
|
|
-- Setup MCP23008
|
|
mcp23008.begin(0x0,gpio2,gpio0,i2c.SLOW)
|
|
|
|
mcp23008.writeIODIR(0x00) -- make all GPIO pins as outputs
|
|
mcp23008.writeGPIO(0x00) -- make all GIPO pins off/low
|
|
|
|
-- Run count() every 100ms
|
|
tmr.create():alarm(100, tmr.ALARM_AUTO, count)
|
|
end
|
|
|