Author Topic: Hacking a Delonghi DH300 P Humidifier for IOT automation with ESP8266 and Blynk  (Read 292 times)

0 Members and 1 Guest are viewing this topic.

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
Dear All,

I  have a dehumidifier (Delonghi DH300 P)
http://www.clubic.com/shopping-409870-3-delonghi-dh-300-p.html#443724
that I want to automate and remote control. In particular, shut down at night because of the noise, and
at peek hours when electricity is much more expensive.

I  first try with a remote controlled main plug, but it does not work  because when turned on,  the control board is off,
and the device does not start until you press the on button.
Same for the pump that is mandatory.

I thus decided to hack directly the board, and add an ESP8266 (or similar to it) for wifi control.
I have already dismounted the board,  but before going further, I am searching here for advice.

 I need essentially two things :

A) Act on the push buttons. The buttons are standard push button
https://www.ebay.com/itm/100PCS-6x6x6-mm-Miniature-Micro-Momentary-Tactile-Tact-Touch-Push-Button-Switch/201538499841?epid=633717124&hash=item2eeca17501:g:hxUAAOSwEOpaA67F
I need, for two of them ( ON/OFF and pump) to simulate the switch from the ESP8266.

The option I think of is  to use a digital switch as the DG412 from intersil
https://www.intersil.com/content/dam/Intersil/documents/dg41/dg411-12-13.pdf which I will
put in parallel to the actual  button switch.

B) Read the led status. For this,  I do not see a very obvious solution.
The anode of the leds is always 5V.
When its on, the cathode  turn to 3V, and is 5V otherwise.

The ESP8266 I use operates at 3.3V, so I need  3 V logic. I  am thinking of using a LM339 quad comparator
as in the attached schematics and hook the output of the comparator directly to the IC IO pin.
The reference voltage (4V) is provided by a resistor divider (40k,10k).



What do you think ?
Will this work ?
Is it overkill ?

Thanks

PS : I will post here the evolution of this project as it can be used for the automation of many devices. The IOT interface will be made using Blynk (https://www.blynk.cc/).

« Last Edit: April 16, 2018, 02:07:06 am by JacquesBBB »
 

Offline NiHaoMike

  • Super Contributor
  • ***
  • Posts: 3786
  • Country: us
  • "Don't turn it on - Take it apart!"
    • Facebook Page
Can you get it to turn on reliably every time power is applied by putting a capacitor across the power button?
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Reference bias: When Allie Moore thinks she's fat after finding out about Naomi Wu.
 

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
I doubt  it .

When you power on the  DH300, you  power the main board  with 5V, which has a MCU.
( Samsung  3F9488XZZ). If you press the  POWER button, the MCU  then activate the relays
that really powers the device.
 

Offline NiHaoMike

  • Super Contributor
  • ***
  • Posts: 3786
  • Country: us
  • "Don't turn it on - Take it apart!"
    • Facebook Page
I have actually used the capacitor trick a number of times. It will probably take some trial and error to find a value that works.

If you hold down the button and plug it in, does it turn on? If it does, some value of capacitor is almost certain to work.
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Reference bias: When Allie Moore thinks she's fat after finding out about Naomi Wu.
 

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
I dont understand the use of the cap. Could you explain how it will work.

In any case, it will not solve my problem, as I want also to have the status of the 4 leds remotely.
In addition, I will still need to have the remote wifi plug ( which I did with a ESP8266).
If I integrate the ESP8266 to the  DH300,
I can use the remote plug for other purpose.

Can you comment on the solution I propose ?
 

Offline TopGunPk

  • Contributor
  • Posts: 20
  • Country: pk
You can send it a command to POWER-ON and OFF via IR signals, just like it's remote controller.

You can capture the Delonghi IR signal on a software like AnalysIR. It uses simple 4-bits to represent different commands,. You can decode the Power ON  /OFF commands.

This signal you can generate from an ESP8266.

Hope this helps.

Regards,
Shan
 

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
There is not IR receiver on the  DH300P.

Here is the schematics of the board I intend to include in my DH300. The JP1 connector will interface with the control board of the DH300 with the following setup :

1 :  5V  ( I identified it from the board.  Most probably the power supply is a Lm7805, so there should be enough power to power this additional board).

2: GND
3 : power button ( The power is active  LOW)
4 : pump  button  (active LOW)
5, 6, 7, 8 :  control LEDS  ( control the voltage of the cathode : 5 V OFF,  3V ON)

« Last Edit: April 17, 2018, 06:08:21 pm by JacquesBBB »
 

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
After mounting the board,

It was not working.

First lesson : I was too optimistic. I soldered directly the nodemcu on the board. I should have put a socket. I had to desolder everything
and  put a socket. I had put sockets on the other  chips.

Second lesson : I am not familiar enough with the nodemcu and ESP8266. I should know that the  D8 pin (GPIO15) is reserved as it needs to be pulled down at boot.

I have revised the schematics :



Moreover I may not need the pullup resistors, and rely on the internal pullup, but will leave it as it is for the moment.
« Last Edit: April 17, 2018, 08:59:03 pm by JacquesBBB »
 

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
Here is the mounted board on a breadboard like PCB.

Not fully tested yet.
I still need  to  make the software.
 

Online JacquesBBB

  • Frequent Contributor
  • **
  • Posts: 777
  • Country: fr
I have now hooked the ESP board to the two buttons and 4 leds of the main DH300 board.

The ESP board find it place very nicely in a free spot of the top of the DH300.

Everything is fully functional, and I can now control the DH300 from my phone.
I will post the program later on here.

I will before add a  BME280 sensor to get some improved humidity and temperature measure.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf