Doing laundry is a task that has to be done with annoying regularity. While the washer and dryer do most of the work, you still need to be around to monitor its operation, transferring and folding clothing as needed. What if your laundry machinery texted you when it was finished, rather than having to listen for it, or remember to check back in an hour or so?
This project by Adam Demuri does just that, using a special Hall effect-based sensor to detect when the appliance is no longer drawing sufficient current for its various spinning and agitation duties. What’s interesting here is that the wires don’t have to be cut, of even split for clamp sensor monitoring. The system can pick up current with AC line and neutral still arranged side-by-side. It’s an ingenious sensor arrangement, with the caveat that the setup is affected by its physical attachment to the wires itself. It therefore needs to be zip-tied into place and calibrated properly.
With electrical current data in-hand, the device’s ESP32 dev board is able to send out an SMS message via Twilio when the load is complete. A simple button/LED interface specifies one of three people to be texted. Laundry is the logical application here, but it could theoretically work with any appliance that sucks a lot of power, then settles to an idle state.