I forgot about three more technical aspects of the device…
The bash script it set up to run as a service in systemd, this is to make it run on startup and have some control over it, this is important for the next part.
The one min delay after submitting the data and shutting down the pi, this gives me time to find the command to stop the script before the script shuts down the pi, this is important so you can access the system and service it.
Why shut it down at all, the power will be cut shortly after?
This is to preserve the filesystem and reduce the risk of corruption, consider that the pi will turn on and off 24 times every day, any error caused by improper shutdowns will quickly amplify.
I think a Pi is an overkill for this. If I were to attempt this, i would try getting it done with an ESP8266 module which uses far less power, making the battery last much longer. Bootup and shutdown times would be much less so using coin cells or supercapacitors charged using small solar panels could also be used. If your home is not too far (few km), using LoRa could eliminate dependency on the WiFi. Cool use case, nonetheless!
A Pi is obviously overkill, even a Pi Z w which we ended up using, but they are efficient enough for us, and more importantly, I know the system, and I could relatively quickly get it working using just bash on the Pi.
I was not really interested in learning how to program on a different system just for this.
We did some power analytics on the Pi and disabled a few things, sorry I don’t remember it right now.
The unit is placed in a semi public place where teenagers sometimes congregate and we don’t want to draw any attention to the device, so solar power is out.
A LoRa unit though could be interesting to implement, sadly my parents house is up a steap hill and there is no line of sight.
I have been thinking of experimenting with Meshtastic and LoRa for off grid coms due to the geopolitical situation here in Europe, might be worth it getting a few units to test out.
I forgot about three more technical aspects of the device…
The bash script it set up to run as a service in systemd, this is to make it run on startup and have some control over it, this is important for the next part.
The one min delay after submitting the data and shutting down the pi, this gives me time to find the command to stop the script before the script shuts down the pi, this is important so you can access the system and service it.
Why shut it down at all, the power will be cut shortly after?
This is to preserve the filesystem and reduce the risk of corruption, consider that the pi will turn on and off 24 times every day, any error caused by improper shutdowns will quickly amplify.
I think a Pi is an overkill for this. If I were to attempt this, i would try getting it done with an ESP8266 module which uses far less power, making the battery last much longer. Bootup and shutdown times would be much less so using coin cells or supercapacitors charged using small solar panels could also be used. If your home is not too far (few km), using LoRa could eliminate dependency on the WiFi. Cool use case, nonetheless!
A Pi is obviously overkill, even a Pi Z w which we ended up using, but they are efficient enough for us, and more importantly, I know the system, and I could relatively quickly get it working using just bash on the Pi.
I was not really interested in learning how to program on a different system just for this.
We did some power analytics on the Pi and disabled a few things, sorry I don’t remember it right now.
The unit is placed in a semi public place where teenagers sometimes congregate and we don’t want to draw any attention to the device, so solar power is out.
A LoRa unit though could be interesting to implement, sadly my parents house is up a steap hill and there is no line of sight.
I have been thinking of experimenting with Meshtastic and LoRa for off grid coms due to the geopolitical situation here in Europe, might be worth it getting a few units to test out.