nodemcu-firmware/lua_examples/irsend.lua

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2015-01-28 08:47:00 +01:00
------------------------------------------------------------------------------
-- IR send module
--
-- LICENCE: http://opensource.org/licenses/MIT
-- Vladimir Dronnikov <dronnikov@gmail.com>
--
-- Example:
-- require("irsend").nec(4, 0x00ff00ff)
------------------------------------------------------------------------------
local M
do
-- const
local NEC_PULSE_US = 1000000 / 38000
local NEC_HDR_MARK = 9000
local NEC_HDR_SPACE = 4500
local NEC_BIT_MARK = 560
local NEC_ONE_SPACE = 1600
local NEC_ZERO_SPACE = 560
local NEC_RPT_SPACE = 2250
-- cache
local gpio, bit = gpio, bit
local mode, write = gpio.mode, gpio.write
local waitus = tmr.delay
local isset = bit.isset
-- NB: poorman 38kHz PWM with 1/3 duty. Touch with care! )
local carrier = function(pin, c)
c = c / NEC_PULSE_US
while c > 0 do
write(pin, 1)
write(pin, 0)
c = c + 0
c = c + 0
c = c + 0
c = c + 0
c = c + 0
c = c + 0
c = c * 1
c = c * 1
c = c * 1
c = c - 1
end
end
-- tsop signal simulator
local pull = function(pin, c)
write(pin, 0)
waitus(c)
write(pin, 1)
end
-- NB: tsop mode allows to directly connect pin
-- inplace of TSOP input
local nec = function(pin, code, tsop)
local pulse = tsop and pull or carrier
-- setup transmitter
mode(pin, 1)
write(pin, tsop and 1 or 0)
-- header
pulse(pin, NEC_HDR_MARK)
waitus(NEC_HDR_SPACE)
-- sequence, lsb first
for i = 0, 31 do
pulse(pin, NEC_BIT_MARK)
waitus(isset(code, i) and NEC_ONE_SPACE or NEC_ZERO_SPACE)
end
-- trailer
pulse(pin, NEC_BIT_MARK)
-- done transmitter
--mode(pin, 0, tsop and 1 or 0)
end
-- expose
M = {
nec = nec,
}
end
return M