Spinning Up A New Laundry Monitor

For all that modern washers and dryers do, they don’t let you know when they’re finished. Or they do, but it’s only a short victory song that plays once and can be easy to miss. What most of us need is a gentle reminder that there’s damp laundry festering in the washer, or fresh laundry in the dryer getting wrinkly.

This laundry monitor from [Sparks and Code] is version 2.0. The first version was working fine, but it was based on vibration (or lack thereof). Fast forward a few years, and [Sparks and Code] got a modern pair that’s so finely tuned, it doesn’t produce enough vibration to register. Back to the drawing board [Sparks and Code] went, and eventually came up with version 2.0.

Now, [Sparks and Code] is detecting whether the machines are on using a pair of split-core transformers to monitor power at the breaker box. With these, you just run the wire through the hole, and it gives the relative mV value going through the wire on a 3.5mm cable. Those cables are connected to an ESP32 inside the 3D-printed box, which is mounted above the cabinet door. Since [Sparks and Code] already has home assistants all over the house, it was easy to integrate and have them all play the message ‘please flip the laundry’.

Once this project was all buttoned up, they thought of one issue — the self-cleaning cycle. Since it takes about four hours, they like to run it overnight. You can see the problem here — no one wants to hear Alexa at 3AM. Fortunately, [Sparks and Code] was able to adjust the Python script to ignore these events. Be sure to check out the build video after the break.

If only the dryer could empty itself and fold the clothes. Oh wait, there’s a robot for that.

17 thoughts on “Spinning Up A New Laundry Monitor

  1. Uh, no. Besides the ‘short victory song’ my LG W/D (and others I’ve seen) gives me a notification on my phone when they finish or if they’ve incurred any problems. And when they need cleaning, And when the filter needs to be replaced. Sometimes I wish they’d shut up.

    1. Some of us don’t like having everything phoning home though. Making a box etc seems like needless work since there are already several cheap esp boxes that have a jack for sensor input for exactly that purpose. Instead of audible alarms, I have the lights in each hallway change color depending on the notification; blue if the other shower is in use (we have old pipes) I’m starting to outgrow how many colors the wife will memorize though so I’m building out LMS with esp32 audio kits.

  2. The more complex a system becomes, the more likely the possibility of an unexpected malfunction. The time it takes to figure it out and then fix it can be more bothersome than the original problem.. Our washer has a buzzer that sounds at end of cycle. But it cant be heard on other side of house. It or a much louder one cant be heard if you’re away from home (shopping, with friends, etc.) Also, it makes more sense to start your wash before leaving house so it will be dryer ready when getting back home.
    Note; in winter when using the heater, hanging wet clothes somewhere in house serves two purposes. It dries the clothes and helps add moisture back into the dry air.
    Dont hang wet clothes inside in summer as the ac has to remove the moisture before it starts utilizing full cooling capacity. One will notice cooler air, the amount depending on capacity of the AC in BTU/hr (british thermal units per hour) The actual decrease in cooling due to wet laundry is minimal.
    In summer it makes more sense to hang wet laundy outside.

    1. I “built” an indoor dryer vent box for winter out of an old plastic trash can and some odds and ends. I turn on the house fan to run at the same time to distribute the extra humidity throughout the house (whose air tends to get too dry in wintertime anyway). Having that extra heat inside the house vs exhausted outside plus a little extra humidity has helped quite a bit with winter time comfort inside.

  3. I follow the rule to not begrudge someone doing something the way they want to do it. When I did this earlier this year, I also wanted to base things on power consumption, and I also wanted to wire it into Home Assistant. You really don’t need to build anything for that since there are plenty of hack-friendly smart outlets that can be monitored by HA.

    Here you go: https://hackaday.io/project/191662-laundry-monitoring

    So far, my alerting is only a blinking box on my HA wall panel, which I have found can be ignored practically forever.

  4. I use a phototransistor to monitor an LED on the front panel of my washing machine. When the wash is done the machine powers itself off, so the LED goes off, and I get a notification.

    1. Been needing to do something similar for an e-bike charger I have that changes an LED from red to green once charging is complete. Would your phototransistor pick up that change?

      1. Doesn’t hurt much to give it a shot. Adding a green color filter to block the red would likely help of it doesn’t work bare.

        A trick that could also work might be to use an LED for sensing since they will actually work in reverse (generate voltage from light).

        The hackers way: Use whatever is on hand to give it a shot and if it works you’re golden.

  5. My washing machine needs two hours for a cycle. So I just come back two hours later. It’s also got a simple 7-segment display that counts down minutes, and during program selection also shows the time of each program, but I always use the same program out of 20 or so possibilities. I just need a cycle to clean my laundry. I don’t know what those other 19 settings are for.

    Another possibility is to go shopping for an afternoon or whatever. If you’re afraid you forgot your washing machine by the time you come back, then trow a T-shirt over your PC monitor (or whatever else you probably do when you come back. Something like that is a strong enough reminder to not forget.

  6. My Dryer has a done/damp repeating alert and it defaults to “ON” anytime I change any of the settings. I too like to run my laundry at night and very frequently, after 1-2am when the dryer’s done it starts beeping until I wake up, get out of bed, and come check it; but there’s unfortunately no script I can just edit. You would think it would eventually turn off after a couple alerts but I’ve come back from a week long trip where I did my sheets before I left and it still has been beeping right along. I have seriously considered on multiple occasions opening it up and taking a pair of pliers to whatever speaker or buzzer is on the inside.

    1. That is nothing you can’t fix with a screwdriver and a plier.
      I had a microwave oven with a similar beeper and it took me about a week before I was fed up with it and ripped the beeper of the PCB.

  7. My LG plays a tune when it’s _almost_ finished. Seriously, it plays the tune, then waits three more mintues before unlocking the door. Why not just play the tune AFTER the door has been unlocked and the washing can be taken out? I can only assume it was designed by a young engineer who still lives at home and has never actually done his own laundry. It’s also a sign that there’s no way I should give these clowns access to my wifi or install any of their apps.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.