1. Design purpose and requirements
Single-chip minimum system + LCD1602 liquid crystal display module + temperature and humidity acquisition module + relay drive module + fan module + LED indicator module + button module + AT24C02 storage module + buzzer alarm module
Specific functions:
2. AT24c02 chip power down storage settings Upper and lower limits;
3. The four buttons are for setting, adding, subtracting, and confirming, which realizes the adjustment of the threshold;
4. LCD1602 liquid crystal display, the upper row displays the current temperature and humidity, and the lower row displays the corresponding cold, hot, dry, and Wet;
5. Equipped with a fully digital temperature and humidity sensor DHT11, the temperature measurement range is 0℃--50℃, and the humidity measurement range is 20%RH-90%RH, which can meet general needs;
6. When the threshold is exceeded, there is The buzzer flashes to warn. And there is a switch to turn off or turn on the alarm;
7. When the temperature or humidity exceeds the limit, the alarm signal light will light up and the corresponding relay will be closed. The relay can drive to open or cut off external devices such as fans, dehumidifiers, heaters, refrigerators, humidifiers, alarms, etc.
2. Design ideas and plans
The hardware is mainly based on the STC89C52 single-chip microcomputer, which displays the temperature and humidity value detected by the sensor DHT11 in real time through LCD1602. The threshold can be stored through AT24C02 to achieve power-off storage and corresponding alarm drive when passing the valve.
3. Hardware circuit
All materials include programs (notes), AD schematic diagrams, protues simulation, reference papers, program explanations, simulation explanations, simulation videos, schematic explanations, introductions to the use of materials, etc., the most comprehensive network! ! ( Https://www.cirmall.com/circuit/18408 )
