Reads #ds18b20s and broadcasts the ID and Temperature via UDP using the #esp8266 SDK.
Switch branches/tags
Nothing to show
Clone or download

README.md

esp8266-UdpTemp

Reads #ds18b20s and broadcasts the ID and Temperature via UDP using the #esp8266 SDK.

  • It will read up to 20 DS18B20s on the bus (or change MAX_DEVICES)
  • It will deep sleep (30uA current) for 2 minutes (or change SLEEP_TIME) (I also removed the resistor from the power LED for lower current draw)
  • It will broadcast on the local net on UDP port 53535 (or change BROADCAST_PORT)
  • It will use 74880 as the baud rate (bootloader baudrate) (or change MYBAUD) Note that FTDI based serial dongles will just work by specifying 74880, if your terminal program allows it. No more garbage on boot!

You MUST connect XPD_DCDC (chip pin #8) to EXT_RSTB (reset) in order for the device to recover from deep sleep mode.

Typical serial output (every 2 minutes)

started
press return to configure wifi.
unless you've configured it once already.
WiFi connecting...1...
WiFi connected
IP: 172.30.1.54
ready
Found:28ae3d1b03000071
bcast: 172.30.1.255
espconn_create result = 0
28ae3d1b03000071:+29.62
deep_sleep

Example UDP packet dump

19:49:52.212203 IP 172.30.1.54.53535 > 172.30.1.255.53535: UDP, length 23
        0x0000:  4500 0033 0003 0000 ff11 6045 ac1e 0136  E..3......`E...6
        0x0010:  ac1e 01ff d11f d11f 001f 773e 3238 6165  ..........w>28ae
        0x0020:  3364 3162 3033 3030 3030 3731 3a2b 3237  3d1b03000071:+27
        0x0030:  2e35 30                                  .50

The actual UDP data payload is

28ae3d1b03000071:+29.62

Very Very stupid configuration example

started
press return to configure wifi.
unless you've configured it once already.

(i pressed return)

got line 
press return again to configure wifi

got line 
enter ssid:YOURSSID
got line YOURSSID
enter pass:YOURPASSWORD
got line YOURPASSWORD
setting wifi config: 
WiFi connecting...1...
WiFi connecting...1...
WiFi connecting...1...
WiFi connected
IP: 172.30.1.54
ready
Found:28ae3d1b03000071
bcast: 172.30.1.255
espconn_create result = 0
28ae3d1b03000071:+28.0
deep_sleep

I've included a schematic and pictures for my little hand wired board in the /hardware folder. Also, I've included a little mod to an FTDI serial dongle so it can power the thing for testing.