A number of my PurpleAir sensors are deployed to remote, high-elevation locations where solar panels are used to provide power to both the PurpleAir sensors and also a portable wifi hotspot that enables the PM data to be uploaded to the PurpleAir map in real time.
During the winter months, the solar panels sometimes go offline – for anywhere from a few days to a few weeks – following periods of heavy snowfall. When this happens, the solar power system disconnects the load when the voltage on its 12V lead-acid battery falls below a certain value, and the PurpleAir sensors thus cease operation until the sun returns and the solar power system comes back online. The portable wifi hotspot runs for a few hours longer on its internal battery (but with no incoming PM data to transmit to the map) and then also shuts down when its internal battery runs out of juice.
When the solar power comes back online, the PurpleAir sensors automatically resume normal operation. But my portable wifi hotspot does not automatically restart – you have to manually depress the on/off switch to bring it back online. (Just like you typically have to do a hard restart of your cell phone after the battery has been run down to zero.) This is a huge problem because this experiment is usually snowed in, with no physical access to the hardware, until the summer months.
Hence, my question: Is anyone aware of portable wifi hotspots that can be configured to automatically restart following an extended power outage, without the need to manually depress an on/off switch? The hotspot does not need its own internal battery – it just needs to power up on its own when the power is restored after an outage.
Thank you !! - Joel B.