A Solar, Waterproof and Wifi thermometer

A Solar, Waterproof and Wifi thermometer

Recently we had to build a device able to measure temperature on a roof. No electricity was available up there, the only technological stuff we could use was a wifi network. That project is not really original since the issues involved have been covered in the mail box and the weather station posts. However we though you would be interested in the box construction....



The box was meant to be attached to a pole, which is installed on a roof. That's why we had to build something tough: we didn't want to go up there for repairs every two weeks. The main idea is to measure the temperature with a Yocto-PT100 connected to a YoctoHub-Wireless-g powered by a USB battery which would be charged with a small solar panel .

The box principle
The box principle


We chose to put all the electronics in a waterproof aluminum box with openings for PT100 probe, the wifi antenna and the solar panel wire. Thanks to the YoctoHub-Wireless sleep feature, the system would be on only a few minutes per hour, so we don't expect any overheating problem. We found all the parts to build the box in local harwdare stores

The projet's main parts
The projet's main parts


The most difficult part to find was a pointable fixing system to attach the box to a pole. We though we would found plenty of ready to use ones. Nope, we had to build one from basic metal hardware, welded and riveted together.

Homemade pointable fixing system.
Homemade pointable fixing system.


We drilled some holes in the back of the box to attach the fixing system and the Yoctopuce devices. Since this required some precision, we used a pre-drilled guide.


 
We drilled some holes in the back of the box


Then we installed some spacers in the box and attached the fixing system. We used screws dipped in epoxy glue to make sure the box stays watertight.


 
This is assembled with screws dipped in epoxy glue


Then we made some openings for the antenna connector, the PT100 probe and the solar panel wire. We also added a waterproof USB socket. This would allow us to configure the system without to having to open it.

The wires openings
The wires openings


The solar panel is attached to two stacked acrylic glass panels with a small opening for the wire. The box lid is attached to the acrylic glass panels as well.


 
The solar panel and the box lid are attached to acrylic glass panels


Then we only had to install the electronic to complete the box. Before closing it, we placed a desiccant bag inside to make sure the humidity trapped inside the box would not condensate.

The electronic part
The electronic part


That architecture suffers from a little caveat: the box lid screws are placed under the solar panel. Should we have to access the electronics, we will have to unmount the solar panel first. That being said we really like our little thermometer box for it's agricultural machinery-like build.


 


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1 - tetaran Sunday,july 19,2015 22H12

Interesting integrated solution. Unfortunately, do do the limited range of WiFi network one cannot use it in remote locations. Have you thought about integrating it into mobile network? There are several really inexpensive cell-modems currently available on market. Data can get pushed on a "cloud" via IP or SMS channel for a further processing.

2 - tetaran Sunday,july 19,2015 22H36

Just an example but more of the same can be located:

http://www.dx.com/p/usb-tri-band-gprs-modem-cell-phone-radio-gsm-900-1800-1900mhz-12057#.VawmCPlVhBc

https://www.youtube.com/watch?v=QeEgsUdZ1hE

3 - martinm (Yocto-Team)Monday,july 20,2015 4H31

We are working on a YoctoHub-GSM, based on a Telit GL865. The hardware is working but the firmware needs more work. No release date available yet.

4 - tetaran Thursday,november 12,2015 3H21

Here is another option you might consider:

http://bladox.com/products.php?lang=cz

Yoctopuce, get your stuff connected.