The Smart Humidor

humidor

If you’re a cigar aficionado, you know storing cigars at the proper temperature and humidity is something you just need to do. Centuries of design have gone into the simple humidor, and now, I guess, it’s time to put some electronics alongside your cigars.

The design of [dzzie]‘s smart humidor consists of an Arduino, WiFi shield, LCD + button shield, and most importantly, a DHT22 temperature and humidity sensor. In a bit of thoughtfulness, only the DHT22 is mounted inside the humidor; everything else is in an enclosure mounted outside the humidor, including a few buttons for clearing alerts and logging when water is added.

The smart humidor reads the DHT22 sensor every 20 minutes and uploads the data to a web server where useful graphs are rendered. The control box will send out an alert email to [dzzie] if the temperature or humidity is out of the desired range.

This Arduino Hookup is Perfect for Microgrowery

to3H8Pa

All it takes is one little seed. One tiny little seed, that when planted into the ground and nourished correctly, can flourish into a healthy and happy plant. But there are some challenges involved. For example, maintaining a steady temperature and keeping moisture at an optimum level can be difficult at times, especially when just starting out.

This Arduino grow-op monitoring solution helps to solve those problems. It was built by [growershower] as a fun side project to monitor the vital signs of 3 marijuana plants. The board is an Uno and has an SD card shield with a DHT22 temperature sensor plus a soil moisture sensor. A photo diode is also used to measure light.

The graph produced from the data is a weed grower’s wet dream:

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Building a replacement for a broken dehumidifier controller

dehumidifier-replacement-controller

We’ve thought of doing a project like this ourselves as the dehumidifier we ordered online runs the fan 24/7 no matter what the humidity conditions. But it wasn’t that [Davide Gironi] was unhappy with the features on his unit. It’s that the dehumidifier controller stopped working so he replaced it with one of his own design. The original humidity sensor was mechanical and simply broke. He used an AVR along with a humidity and frost sensor to get the appliance up and running again.

A DHT22 humidity sensor is polled by the ATmega8 chip and compared to the user-adjustable trimpot value. If it is above that threshold the unit is switched on using one of the relays seen in the image above. The one problem you have to watch out for when using compressor cooled appliances is ice accumulation on the radiator. [Davide] uses a thermistor for temperature feedback, switching the compressor off when it gets below 7C and turning it back on again when it is above 12C.

The replacement still uses the reservoir sensor and indicator LEDs. We, however, would recommend using the watchdog timer on the chip to ensure that it is reset if something goes wrong in the code.