Philips AirFryer V3
With a Wi-Fi WebSocket Server, meat probe and five programmable stages.

Wi-Fi AirFryer V3
That's a Philips AirFryer, programmable over Wi-Fi with a ESP32 WebSoket ¹) Server and a HTML5-Client.
This project is a replacement of the original (defect) Philips AirFryer PCB, Philips part:
          4203 036 07241 Power supply PCB assy coated (pos 22, in project zip: AirFryer Philips HD9240.pdf )
Total cost: ~$/€ 35.00.
¹) WebSocket?: Real-time bidirectional event-based communication.

Now a AirFryer with new features:
- Five stages: Preheat, three Fryer sets and Rest.
- Shake or Flip your food and Ready signals (MP3).
- And now you can also use a meat probe.

Safeties:
- DANGER, 110-240V AC Power: This is not a beginners project.
        If you have no experience with mains voltage then forget this project!
- CAUTION, risk of fire: Use this AirFryer project only at you own risk! I will not accept any liability!
- If no user action on "insert your food" then after five minutes the AirFryer STOPS.
- If overheating the AirFryer STOPS.

Hardware:
Very affordable on Banggood/AliExpress/OPENcircuit. For configuration examples see images and/or Fritzing (in the download).

• ESP32 dev kit
• Power supply 140-250VAC to 5VDC, min. 1A
• 2 or 3 relays (voltage and power depending on the fan and  the heating element)
  (the Arduino/ESP relay modules are NOT 250VAC 10A, i don't use modules and use a third true 16A relay)
• 2 momentary buttons
  or use the ESP32 Touch ports
• Red LED
• Resistors: 680Ω (LED), 2 x 20KΩ (NTC),
  2 x 10KΩ or ... (transistor Base)
• 2 transistor S9013 or ...
•  2 diode 1N7004 or ... (used on relays)
• Prototype PCB Board, 11x4 cm
• 2 fuse 16A slow
• Male/female headers and wires as needed
• Maverick ET-73 meat probe
• 2.5mm Stereo jack panel mount (meat probe)

Enclosed PDF in the ZIP-file: Philips AirFryer Service Manual.

Software:
Download my AirFryer project here.
Use the latest Arduino IDE and Arduino/ESP32 libraries or, if you are an advanced programmer, PlatformIO.
We use only the third-party library "WebSocketsServer.h" from https:/github.com/Links2004/arduinoWebSockets.
The HTML is a simple test and demonstration of AirFryer. Develop your own (graphical) user interface in HTML/JavaScript.
The AirFryer WebSocket Server must have a static IP.

Edit this:
In AirFryer.html: edit the edit this section.
In EditMe.h: change it to your choices, you can also choose Celsius or Fahrenheit.

Thermistors:
We use the Steinhart-Hart model coefficients A, B and C parameters. Or, if you change the code, use the NTCcalculator.
In the AirFryer user interface you see every 2 sec. an update of the calculated thermistor resistance(s) and the calculated temperature(s).
For more thermistor information search the Web for (Arduino/BBQ) thermistor.

PID control?
I have no PID control applied. Over/undershoot of the AirFryer temperature has, in my experience, no adverse consequences for the food.
But, if still desired then the Arduino PID library a very good choice. I use this PID library in my Sous-vide projects, with an accuracy of 0.06°C.

Five stages:
Using a modern standard browser to set the parameters and start frying.
You can use, add and/or edit preset recipes.

Set stages and start:

1. Preheat
   • Set temperature (0: not used, skip)
2. Frying (low/high roast?)
   • Set temperature (0: not used)
   • Set time in minutes
   • Set shake/flip interval  in minutes (0: no shake)
3. Frying (high/low tender roast? Using meat probe?)
   • Set temperature (0: not used, skip)
   • Set time in minutes
          or, if using an meat probe
     Set a negative value as internal meat temperature
   • Set shake/flip interval  in minutes (0: no shake)
4. Frying (high crispy roast?)
   • Set temperature (0: not used, skip)
   • Set time in minutes
   • Set shake/flip interval  in minutes (0: no shake)
5. Rest (Resting Meat?)
   • ------ (not used)
   • Set time in minutes (0: not used, skip)
   • Use fan? 0:OFF, 1:ON

Connect to the AirFryer Server and Start frying.

On frying:

1. Preheat (or skip)
   • Wait for MP3 signal: "insert your food"
     • push red button
     • insert the food
     • push green button
2. Frying (or skip)
   • If shake interval:
     On MP3 signal:  "shake your food"
     • push red button
     • shake/flip the food
     • push green button
3. Frying (or skip)
   • If using a meat probe (on negative minutes value)
     • If internal temperature OK then next stage
   • If shake interval:
     On MP3 signal:  "shake your food"
     • push red button
     • shake/flip the food
     • push green button
4. Frying (or skip)
   • If shake interval:
     On MP3 signal:  "shake your food"
     • push red button
     • shake/flip the food
     • push green button
5. Rest (or skip)

 Wait for MP3 signal: "your food is ready".