Receiving wrong data from ds18b20 on thingspeak
Posted: Mon Feb 13, 2017 12:26 pmHello, it is my first journey with esp8266 but im almost done.
From the beginning:
a) flash nodemcu_float_0.9.6-dev_20150704.bin with esp8266 flasher - done
b) 2 lua files uploaded via ESplorer - done (id and password good, ping ok)
+
ds18b20 connected with several options
a) VCC, GND to GND / Data to GPIO0
b) VCC, GND to GND / Data to GPIO2
c) VCC to VXX, GND to GND / Data to GPIO0
d) VCC to VXX, GND to GND / Data to GPIO2
Everytime i got wrong data sent to thingspeak :
https://thingspeak.com/channels/226740
Any ideas ?
//i tried other firmwares and still -0.0999 or -1.0999.
From the beginning:
a) flash nodemcu_float_0.9.6-dev_20150704.bin with esp8266 flasher - done
b) 2 lua files uploaded via ESplorer - done (id and password good, ping ok)
Code: Select all
--init.lua
print("Setting up WIFI...")
wifi.setmode(wifi.STATION)
--modify according your wireless router settings
wifi.sta.config("xxxxxxx","zzzzzzzzz")
wifi.sta.connect()
tmr.alarm(1, 1000, 1, function()
if wifi.sta.getip()== nil then
print("IP unavaiable, Waiting...")
else
tmr.stop(1)
print("Config done, IP is "..wifi.sta.getip())
dofile("ds1820.lua")
end
end)
+
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 = 3
ow.setup(pin)
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()
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')
conn:send("GET /update?key=4Bzzzzzz2BBI&field1="..t1.."."..string.format("%04d", t2).." 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)
end
-- send data every X ms to thing speak
tmr.alarm(0, 60000, 1, function() sendData() end )
ds18b20 connected with several options
a) VCC, GND to GND / Data to GPIO0
b) VCC, GND to GND / Data to GPIO2
c) VCC to VXX, GND to GND / Data to GPIO0
d) VCC to VXX, GND to GND / Data to GPIO2
Everytime i got wrong data sent to thingspeak :
https://thingspeak.com/channels/226740
Any ideas ?
//i tried other firmwares and still -0.0999 or -1.0999.