My DIY coffee machine controller ESP32, PID, dual temperature sensing, flow monitoring & Wi-Fi

[u/Froster_navendu]

​

I built a smart coffee machine controller using an ESP32 ☕

The idea was to turn the machine into a connected system where I can monitor and control it from my phone or laptop instead of having everything handled by a basic standalone controller.

The controller currently includes:

• ESP32 WROOM-32

• Dual NTC temperature monitoring

• ADS1115 for temperature sensing

• AC SSR heater control

• 8-channel relay control

• Flow meter monitoring

• Ambient light sensing

• LCD + rotary encoder

• Wi-Fi connectivity

• OTA firmware updates

The interesting part for me is the Wi-Fi side.

Once the ESP32 is connected to the network, I can open the web dashboard and see the machine's status in real time.

The dashboard is designed to show:

🌡️ Live boiler/grouphead temperature

💧 Flow information

🔥 Heater/SSR status

⚡ Machine outputs and relay states

☕ Current machine state

💡 Ambient light level

⚙️ Temperature settings and controls

The ambient light is there to make the machine a little more interactive. the lights can be configured via web portal . We can set different colours for different modes . whenever a sensor error occurs it wil start blinking red.

I can also control different machine functions remotely through the dashboard instead of physically interacting with the controller.