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Tech Forum

April 2017

Warm Cows Are Happy Cows

My daughter is in 4H and has a calf we are raising in a shed behind the house. Recently, the bulb burned out on the heat lamp we leave on to keep the cow warm. Is there a simple circuit I could use to remotely monitor the temperature and alert me if it drops below a set point? I know there are remote temperature gauges but I need one with an alert or a way to hack one to add an alert. Any ideas welcome.

Robert Lowery
Florence, SD


Simplest is a standard (cheapest bimetallic) house thermostat, a battery, and a simple DC bell! You don’t have to drill any holes or screw anything up, and the wire can be taken through a window into the house. I’m sure you could also rig up something like an arduino with hats and bluetooth or Wi-Fi with phone messaging, but unless you want to do extensive datalogging, I can’t see the point...

But that’s often beside the point in hobbyist systems.

Sally Jelfs

Sounds like a job for the Raspberry Pi 3 computer connected to a DS18B20 temperature sensor with Cayenne software installed on both the Raspberry Pi and mobile phone. Cayenne is a software platform from MyDevices that acts as a gateway to the Internet of Things (IoT), the service is free. You can view temperature data from your mobile phone, or configure Cayenne to send a text message alert when the temperature drops below a set threshold. The Raspberry Pi can be connected to your home network using Wi-Fi or wired connection.

Norman Ma
Calgary, Alberta