From Market to Home (Smart Cold Storage Thermostat & Spoilage Monitor)
Source: Stemoto Original
Build a mini cold storage box for perishable vegetables (Spinach, Tomatoes). A Peltier thermoelectric cooling module / fan with DS18B20 thermostat maintains 4°C to prevent vegetable spoilage.
Categorisation
Props & Materials Required
- •Insulated foam cold storage box model
- •12V Peltier thermoelectric cooling element + mini 5V cooling fan
- •DS18B20 digital temperature sensor probe
- •ESP32 controller board
- •0.96-inch OLED display screen
- •DFPlayer Mini MP3 module + 3W speaker
Step-by-Step Instructions
Store Fresh Tomatoes inside Cold Box
Place fresh tomatoes inside the insulated cold storage box.
Set Target Storage Temp
Set target temperature to 4°C on the OLED screen.
Peltier Cooling Fan Runs
DS18B20 probe reads 28°C inside. Controller turns ON Peltier cooler fan unit.
Thermostatic Cutoff
Temperature drops to 4°C. Cooler fan switches OFF to save energy! Speaker: 'Cold storage optimal! Tomatoes preserved for 14 days!'
Why It Works & Notes
From Market to Home explores why some vegetables spoil fast (spinach/tomatoes) while others last long (potatoes/onions). Building a thermostatically controlled cold storage unit demonstrates cold-chain preservation.
Looking Around Chapter 15: From Market to Home | STEM Tech: Thermoelectric Peltier Cooling & Closed-Loop Thermostatic Control — cold chain logistics for fresh produce.