Friends asked me to make a wood dryer alarm controller.
Push more for details.
A seven-segment display with a common cathode is used as an indicator. Cathodes are alternately connected to ground by PDTC144ET transistors to provide dynamic indication.
I used an Arduino pro mini board as a controller.
The device is assembled on breadboards and assembled into a junction box
The device has four buttons, the left set the lower temperature threshold, the right upper threshold, the middle values are written in ROM. A red button is required to turn off the siren.
The device activates the siren if the temperature rises above or below the set limits.
Transistor key for siren control
IRF740 MOSFET transistor to drive siren
Temperature sensor DS18B20
Sketch program for the device
Thank you all for your attention!