Notes on Evakool Fridge WiFi Protocol

README.md

evakool

My evakool fridge comes with an app that connects over WiFi to a proprietary TCP service. ie: not HTTP.

The Android app that talks to this TCP service is shit.

I'm going to attempt to make a less shit app.

The Network

You connect to a WiFi network named JTZNBX_<FRIDGE_ID>

In my case <FRIDGE_ID> is 767BC1

The fridge hands out DHCP addresses, where it is the default gateway of 192.168.4.1/24

The WiFi network it's self is unprotected.

Protocol Spec

Assuming you can ping the fridge then these are the commands you can send it over TCP port 180.

Login

The <USERNAME> & <PASSWORD> appear to be static, I got them from this manual: https://www.evakool.com.au/core/media/media.nl?id=62328&c=6457383&h=op1S_KjoBH-SUttFdrA5xkhUzQJeTB2U0QASk1xH3-ssQ5Zr&_xt=.pdf

• TX: JTZNBX2015#login#<FRIDGE_ID>#<USERNAME>#<PASSWORD>#

  • eg: JTZNBX2015#login#767BC1#12345678900#123456#

• RX: SUCCESS#76#1#

  • No idea what the 76 & 1 mean

Read State

This is perhaps going to be the most useful thing we get out of the the fridge.

• TX: JTZNBX2015#read_state#

• RX: SUCCESS#<CURRENT_TEMP_LEFT>#<CURRENT_TEMP_RIGHT>#<REQUESTED_TEMP_LEFT>#<REQUESTED_TEMP_RIGHT>#<VOLTS>#<VOLTS_DECIMAL>#10#0#

  • eg: SUCCESS#2#-16#0#-18#27#16#10#0#
  • I think the last 10#0 may have something to do with the low voltage cut off setting
    • 10 = HIGH VOLTAGE CUTOFF = 11.8
    • 9 = MEDIUM VOLTAGE CUTOFF = 11.4v
    • 8 = LOW VOLTAGE CUTOFF = 10.1v
    • Still no idea what the last #0 means???
      • Actually at a guess I think it might be like an error code. The android app has a box with the words "Fridge working properly" but I guess it's possibly that could contain other messages based on this last last digit.
        • In the manual there are a list of error codes, my guess is that this last digit relates to this in some way.
          • ER1: Thermistor is Unplugged
          • ER2: Thermistor is Short Circuited
          • E1: Low Voltage
          • E2: Fan Issue - Fan is drawing too many Amps (Over 1 Amp).
          • E3: Compressor Start Issues
          • E4: The Compressor Speed is Too Low
          • E5: Ambient Temperature Too High

• RIGHT = SMALLSIDE (has shelf at least on my TravelMate 80L)

• LEFT = BIGSIDE

Set Config

• TX: JTZNBX2015#setconfig#50#32#<XFACTOR>#

  • XFACTOR: 8 low volts & celsius
  • XFACTOR: 9 med volts & celsius
  • XFACTOR: 10 high volts & celsius
  • XFACTOR: 12 low volts & ferhnheight
  • XFACTOR: 13 med volts & ferh
  • XFACTOR: 14 high volts & fern
  • Seems to +4 for ferhnheight
  • Not sure what that #50#32# are yet, i presume temp but that have not changed throughout
  • Added 1 degree to LEFT and I now get #51#
  • Did the same for RIGHT and got #33#
  • So I presume JTZNBX2015#setconfig#<REQUESTED_TEMP_LEFT>#<REQUESTED_TEMP_RIGHT>#<XFACTOR>#
  • But when setting the temp it's always in Ferhinheight???

• RX: SUCCESS

Graphs

Honestly though I think we can just poll the read state function ourselves

• TX: JTZNBX2015#read_<Y>_<X>#
  • <Y> = wd1 = left temp
  • <Y> = wd2 = right temp
  • <Y> = dy1 = volts
  • Where <X> is 1 through 8, like paging I think
  • You get back a whole heap of crap that I really can't be bothered with right now.
  • Like I say we will just poll the read state & put results into our own db.

ON/OFF

Settings XFACTOR to 2 seems to turn the fridge off. Setting it back to 10 or a I guess a valid value turns it back on.