My ESP8266 weekend project - Dehumidifier Alert System - Page 1
Forum section: electronics / projects

author: Eric_the_EE
author_rank: Contributor
timestamp: June 17, 2018, 04:24:05 pm
content: I recently purchased a Honeywell dehumidifier for my basement. I only go to the basement 2-3 times per week since it is only used for storage and laundry washing/drying.Unfortunately I don't have a drain accessible to hook the dehumidifier up for continual draining (cannot access washing machine drain without some real work). So my dilemma was that I would have to start frequently going to the basement to check if the dehumidifier water basin was full - a very annoying and inefficient way to own a dehumidifier.To maximize the efficiency, I should empty the dehumidifier as soon as it is full and not have to check it frequently.So...I took it apart, found a 12V power rail, ground, and a 5V signal from the "water basin full" switch.I thought I'd try this ESP8266 module from Sparkfun:https://www.sparkfun.com/products/13678I currently am out of protoboard, so I designed and ordered PCBs from PCBWay since it isn't really more expensive than ordering more protoboard anyway. KiCAD archive is attached.I used this ESP8266 tutorial to get off and running:https://circuitdigest.com/microcontroller-projects/sending-sms-using-esp8266After my PCBs arrived, I was able to assemble, install, program, and start receiving SMS messages all in a Saturday afternoon. Happy first experience with the ESP8266 (I should use these more often). See the attached pictures.Arduino sketch is also attached - as the Circuit Digest tutorial shows, you will have to at the very least change your network SSID, Password, and IFTTT url for your own application.Cheers

author: floobydust
author_rank: Super Contributor
timestamp: June 17, 2018, 08:44:25 pm
content: It looks like an interesting project, thanks for posting your work.I have troubles with ESP8266 example code out there being very stupid for the WiFi connection.If there is a dropout in the WiFi connection (i.e. router gone/rebooting), the ESP8266 code hangs and needs a cold boot to fix.The code will not retry connecting to the router (that's only in Setup) and a connection fail (result=1) doesn't do anything to retry, so you get in a forever loop of no Wifi connection.Just something to consider, if you do not hear anything for a while, go reboot the unit. Or a timer and beeper if a flood can happen.If your water sensor probe corrodes, I suggest stainless steel or AC excitation instead of a pullup resistor.

author: CopperCone
author_rank: Super Contributor
timestamp: June 17, 2018, 09:07:10 pm
content: cant you connect it to a bucket with a sump pump and a float in it? that looks like a ridiculous amount of work.

author: Eric_the_EE
author_rank: Contributor
timestamp: June 17, 2018, 09:09:09 pm
content: floobydust -Good thoughts. I should add some software mechanisms for increasing the connection reliability. I didn't bother at this point, throwing it together in an afternoon, but you're right, for long term reliability, I should add some things.Floods are not a worry because I am just piggy-backing off the dehumidifier's built-in water level switch (not my own level sensor). When the switch trips, the dehumidifier automatically shuts off so that it will not flood. But this is why I wanted to be alerted when it is full - because it shuts off and will not operate until emptied. So it is most efficient if I am alerted when it is full, empty it ASAP, therefore minimizing non-operating time.Good thoughts on the connection software - I will do some development and add a follow-up post later.

author: Eric_the_EE
author_rank: Contributor
timestamp: June 17, 2018, 09:18:26 pm
content: CopperCone -What looks like a "ridiculous amount of work"? Designing a simple PCB? Writing an Arduino sketch? Both I did in one afternoon. Or do you mean emptying the dehumidifier when it fills? (takes 60 seconds to do).I don't have a sump pump nor drain easily accessible, so my solution meets my needs for now. Depending on the RH, it has been taking 8-12 hours to fill, so I end up emptying it 2-3 times per day during the Spring and Summer months.Besides, being an electronics engineer and hobbyist, I jump on every electronics project opportunity that comes along.