Hi guys, first time poster here and newbie with electronics. Hoping someone can help me out.
I want to make a temp sensor to monitor a wine fridge that’s been playing up recently. I have a couple of Raspberry Pi’s sitting around doing nothing and thought I might be able to put them to use.
Anyone know if there’s an easy way of making one ? Would like it to be able to hook up to my wifi network and send email etc when thresholds are exceeded etc.
thanks in advance.
Adam
Welcome Adam.
Adafruit has a guide to connecting ds18b20 sensors to Raspberry Pi. I’m not sure how current it is for a Raspberry Pi 3.
Little Bird have several ds18b20 sensors and I guess a waterproof one would be best, although the cable may be a challenge to get through a fridge seal. Best is to drill a hole if you can be sure where to do the drilling without killing yourself on internal wiring. Check with manufacturer for details.
What I’ve done once is take flat telephone cable, such as this type, and carefully remove the outer insulation for about 40mm, and use that section between the fridge door seal. I’ve used adhesive tape to hold the cable cores down.
You can also use a Raspberry Pi 3 and WiFi with a local battery inside the fridge, but that will make a small amount of heat and you have to keep changing the battery.
Hope that helps!
Thanks for that. quick question, can you give me a link for the jumper wire pack I would need ?
Sorry, for the delay, was travelling.
can you give me a link for the jumper wire pack
Not really. There are too many and there’s no parametric selector. Take your pick. Look at price, availability, and if the pins are square or round. Square work best in breadboards, as the contact area is usually maximised, but it depends on the breadboard.
You’ll need three female to male jumpers of about 40mm to 110mm for the hop from the Raspberry Pi I/O port to a breadboard where the 4k7 resistor will live, then the sensor cable(s) can plug in there. If the sensor cable doesn’t have pins (some do not), then grab a pack of pins and use either pliers or the crimping tool. Insulate them with tape or use the rectangular plastic bits.
Also recommend taking care with electrostatic discharge when working on the Pi; where I am in the outback the humidity is sometimes so low that things die from it. 