Nobody likes to monitor things as much as a hacker, even mundane things like sump pumps. And hackers love clean data too, so when [Felix]’s sump pump water level data was made useless by a new pump controller, he just knew he had to hack the controller to clean up his data.
Monitoring a sump pump might seem extreme, but as a system that often protects against catastrophic damage, the responsible homeowner strives to take care of it. [Felix] goes a bit further than the average homeowner, though, with an ultrasonic sensor to continually measure the water level in the sump and alert him to pending catastrophes. Being a belt and suspenders kind of guy, he also added a float switch to control the pump, but found that the rapid cycle time made his measurements useless. Luckily the unit used a 555 timer to control the pump’s run time after triggering, so a simple calculation of the right RC values and a little solder job let him increase the on time of the pump. The result: a dry basement and clean data.
We recently discussed the evolution of home automation if you want to know more about the systems that sensors and actuators like these can be part of. Or for a more nuts and bolts guide to networking things together, our primer on MQTT might help.
We’ve got some friends who have two sump pumps. One is a backup and sounds an alarm when it is switched on. But this only works as long as they’re home to hear it. [Felix Rusu] came up with a solution what will text him if the sump pump fails. This way he can head home, or call someone to check in on the problem if he’s away.
We saw a pretty complicated monitoring system back in January. This one uses a single ultrasonic rangefinder which we think is much simpler. It’s accurate to about 1cm and is simple to use — it’s very popular with the hobby electronics crowd which helps with price and availability of sample code. We hem and haw about the use of a Raspberry Pi board with the project. On the one hand it’s a cheap way to get the sensor on the network and provides the infrastructure you need to send any number of alerts. On the other hand, it’s a lot of power for this particular application. But we figure it can be extended to monitor other utilities in [Felix’s] home, like a sensor to alert him of a leaking water heater. And we think everyone can argue that a monitor like this is well worth the time and effort he spent to develop it.
[Matt] literally finds himself in a sticky situation. There’s an oil slick in his sump well. These wells work in conjunction with drain tiles to pump water away from the foundation of a house. Unfortunately the tar that was used to waterproof the outside of his foundation is also washing into the sump and gumming up the works. The system he built will sound an audio alarm and send an email if something goes wrong with the sump pump.
He’s monitoring for two different issues. One technique uses a float valve to sense if the water is too high, signalling that the mechanism controlling the pump has malfunctioned. The other is a current monitor that senses if the sump pump has been running too long (caused by the sump’s water sensor getting stuck in the on position). The one thing he didn’t want to do is control the pump directly as a bug in his code will easily result in a flooded basement. We have the same concerns when considering building a DIY thermostat (an error there could mean frozen water pipes leading to flooding).