- Mon Sep 21, 2015 7:50 am
#29577
Hi folks,... I am trying to develop/extend and existing program that takes temperature samples from a DS18b20 temperature sensor and then logs the data to thingspeak... running of an ESP8266-07
I have had the basic program working fine,.. even created a *.lc file to save space,.. but unfortunately when I try to add some functionality to toggle an LED on and off every-time a sample is sent,.. and flash another LED when the 8266 starts to talk to thingspeak.
Looking at the code I figured shifting the one function into its own file would fix the space issue,.. and I could then develop the other function with more space to play with.
My thought was to shift out the getTemp() but then I get unsure how lua handles calling/loading functions and passing parameters back to the sendData() function,... I have searched lua forums and found info about modules but not how to call functions with other files.... or how to actually split the functionality up,..
And yes I may well be missing the obvious and I may well be barking up the wrong tree,... I am new to lua,.. can someone point me help me in the right direction..
many thanks
I have had the basic program working fine,.. even created a *.lc file to save space,.. but unfortunately when I try to add some functionality to toggle an LED on and off every-time a sample is sent,.. and flash another LED when the 8266 starts to talk to thingspeak.
Looking at the code I figured shifting the one function into its own file would fix the space issue,.. and I could then develop the other function with more space to play with.
My thought was to shift out the getTemp() but then I get unsure how lua handles calling/loading functions and passing parameters back to the sendData() function,... I have searched lua forums and found info about modules but not how to call functions with other files.... or how to actually split the functionality up,..
And yes I may well be missing the obvious and I may well be barking up the wrong tree,... I am new to lua,.. can someone point me help me in the right direction..
many thanks
Code: Select all
-- Measure temperature and post data to thingspeak.com
-- 2014 OK1CDJ
--- Tem sensor DS18B20 is conntected to GPIO0
--- 2015.01.21 sza2 temperature value concatenation bug correction
pin = 6 -- Assign pin to DS18b20
led1 = 2 -- Assign Pin to LED
ow.setup(pin)
gpio.mode(led1, gpio.OUTPUT)
counter=0
lasttemp=-999
-- *****************************
function bxor(a,b)
local r = 0
for i = 0, 31 do
if ( a % 2 + b % 2 == 1 ) then
r = r + 2^i
end
a = a / 2
b = b / 2
end
return r
end
-- *****************************
--- Get temperature from DS18B20
function getTemp()
addr = ow.reset_search(pin)
repeat
tmr.wdclr()
if (addr ~= nil) then
crc = ow.crc8(string.sub(addr,1,7))
if (crc == addr:byte(8)) then
if ((addr:byte(1) == 0x10) or (addr:byte(1) == 0x28)) then
ow.reset(pin)
ow.select(pin, addr)
ow.write(pin, 0x44, 1)
tmr.delay(1000000)
present = ow.reset(pin)
ow.select(pin, addr)
ow.write(pin,0xBE, 1)
data = nil
data = string.char(ow.read(pin))
for i = 1, 8 do
data = data .. string.char(ow.read(pin))
end
crc = ow.crc8(string.sub(data,1,8))
if (crc == data:byte(9)) then
t = (data:byte(1) + data:byte(2) * 256)
if (t > 32768) then
t = (bxor(t, 0xffff)) + 1
t = (-1) * t
end
t = t * 625
lasttemp = t
print("Last temp: " .. lasttemp)
end
tmr.wdclr()
end
end
end
addr = ow.search(pin)
until(addr == nil)
end
-- *****************************
--- Get temp and send data to thingspeak.com
function sendData()
getTemp()
gpio.write(led2, HIGH);
t1 = lasttemp / 10000
t2 = (lasttemp >= 0 and lasttemp % 10000) or (10000 - lasttemp % 10000)
print("Temp:"..t1 .. "."..string.format("%04d", t2).." C\n")
-- conection to thingspeak.com
print("Sending data to thingspeak.com")
conn=net.createConnection(net.TCP, 0)
conn:on("receive", function(conn, payload) print(payload) end)
-- api.thingspeak.com 184.106.153.149
conn:connect(80,'184.106.153.149')
-- XDP4IIJT65R8QFGR
--conn:send("GET /update?key=XDP4IIJT65R8QFGR&field1="..t1.."."..string.format("%04d", t2).." HTTP/1.1\r\n")
conn:send("GET /update?key=XDP4IIJT65R8QFGR&field1="..t1..".".." HTTP/1.1\r\n")
conn:send("Host: api.thingspeak.com\r\n")
conn:send("Accept: */*\r\n")
conn:send("User-Agent: Mozilla/4.0 (compatible; esp8266 Lua; Windows NT 5.1)\r\n")
conn:send("\r\n")
conn:on("sent",function(conn)
print("Closing connection")
conn:close()
end)
conn:on("disconnection", function(conn)
print("Got disconnection...")
end)
gpio.write(led2, LOW);
end
-- *****************************
-- send data every X ms to thing speak
tmr.alarm(0, 60000, 1, function() sendData() end )
