Author Topic: Door open timer switch thingymajig  (Read 1208 times)

  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #15 on: September 18, 2021, 19:54:43 PM
Cool basically if you get something working, I’d recommend still running it from an ESP just because they are smaller, cheaper and usually more powerful.. if you need any help let me know
So funny, when I first asked the question and you started talking about ESP stuff I had no idea what you were talking about except it sounded like extra work.

Now I find myself looking at them and thinking that's the next step. I just need to work my way through the Arduino boards I've bought so far first haha.

I'm building a fairly broad air quality monitoring gadget which is currently using a Mega as the number of sensors exceeded the Unos capabilities. Already I'm thinking that WiFi would be nice, but maybe I'll keep that for V2.

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Re: Door open timer switch thingymajig
Reply #16 on: September 18, 2021, 20:17:03 PM
Now I find myself looking at them and thinking that's the next step. I just need to work my way through the Arduino boards I've bought so far first haha.

Haha, I’d highly recommend the Wemos D1 Mini (this is the ESP favourite in the community), it’s pretty much adding one line in to the arduino IDE to support pretty much all ESPs, they are cheaper than arduino, gives you WiFi, are easy to stack accessories and proto boards, will just run off usb for the most part (if you need more power solder over the regulator or power direct from the 5v pin) if you have any questions or problems I’m happy to jump on any chat/screen share platform

  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #17 on: October 04, 2021, 21:25:34 PM
Version 2.0 with fan control. Makes a huge difference, thanks knighty.

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Re: Door open timer switch thingymajig
Reply #18 on: October 05, 2021, 07:28:28 AM
That looks excellent! Which display are you using? And any pics of the inside?

I guess you have additional circuitry to handle the fan load, if so you can simplify this with a PWM fan.

Also if still considering the ESPs, checkout the TTGO boards with built in colour display, buttons, WiFi and Bluetooth  and powerful enough to run Tetris!

  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #19 on: October 05, 2021, 07:40:07 AM
It's just a bog standard 0.96" I2C oled display. Was going to put a scrolling graph but not enough memory on the nano.

No clear pictures of the inside, but details are:

Nano Pro microcontroller.
BME280 temp/humidity sensor
5v relay
5v 1" fan
0.96" oled
Thin film pressure sensor
RGB led with resistor.
Active buzzer

The fan is hooked to the relay which is hooked to the 5v out pin.

The pressure sensor is on the 3.3v rail so max analog output is 6xx. Basically have the door open alarm set so that when the pressure drops below 500 it's open, turns fan off, and starts the countdown to the buzzer going off. Also changes the Led from green to red.

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  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #20 on: October 05, 2021, 07:43:34 AM
Will check out the ttgos... I just bought a pack of 10 d1 minis for temp/humidity monitoring through the house.

Still have a big air quality monitoring project to work on but the sensors are pretty naff. Tend to drift and don't provide very meaningful results.

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Re: Door open timer switch thingymajig
Reply #21 on: October 05, 2021, 08:40:47 AM
Nice, looked like you’ve got it pretty compact too!

  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #22 on: October 05, 2021, 08:43:20 AM
Yeah, have found getting things into a small package the biggest challenge. Many headaches!

Tend to solder most stuff on but then have to use header pins to do final connections between the two sections using a pair of tweezers to hook em up! Think the motor wires and oled screen are connected that way so if I need to open it up I can.

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Re: Door open timer switch thingymajig
Reply #23 on: October 05, 2021, 09:08:35 AM
I just bought a pack of 10 d1 minis for temp/humidity monitoring through the house.

Still have a big air quality monitoring project to work on but the sensors are pretty naff. Tend to drift and don't provide very meaningful results.

The D1's will be ideal for that, just a couple of things to consider for temp monitoring, which might not be so much of an issue with the BME280 but I had a couple of challenges when using a thermistor.. Obviously proximity to the ESP/Arduino can throw the readings off just due to the heat being generated from it, but the other issue I found using a thermistor was that keeping it powered constantly would cause itself to generate heat throwing off the readings over time (which is kind of obvious in retrospect) but was just using what I had handy at the time!

Yeah, have found getting things into a small package the biggest challenge. Many headaches!

Tend to solder most stuff on but then have to use header pins to do final connections between the two sections using a pair of tweezers to hook em up!

On the D1 this is where the stackable proto boards can come in handy BTW
Last Edit: October 05, 2021, 09:15:50 AM by XEntity #187;

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  • Offline Clock'd 0Ne

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Re: Door open timer switch thingymajig
Reply #24 on: October 05, 2021, 09:26:59 AM
I can't add anything of value here except to say that this is really cool stuff, nicely done  8)

  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #25 on: October 05, 2021, 09:33:40 AM
Heh, I think temp changes are what are throwing my air sensors off. Get everything stable and take it outside and it instantly reads a different value. Not because there's H2S in the air, but because its gone from 20 degrees to 10.

Will probably need to build in temperature compensation but not all the sensors data sheets provide temperature offset info.

Also, have you noticed how hostile the Arduino forums are? I've never seen anything like it. Literally all questions have to be written in such a detailed way that takes way too long to do or they descend en masse to have a go at the poster.

And on the rare occasion they're polite, inevitably they start bickering amongst themselves.

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  • Offline zpyder

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Re: Door open timer switch thingymajig
Reply #26 on: October 05, 2021, 09:36:41 AM
a fan should make a a massive difference...

you'll defiantly have a dryer area around the silica and a wetter area around the stuff being dried
Turned out the air in the silica tray was about 3-4%. And at the top of the cabinet would be about 30%

The fan helps even things out. Also interesting to see the silica colour is noticeably changing by the end of the day so it's obviously doing more drying than it did pre-fan.

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Re: Door open timer switch thingymajig
Reply #27 on: October 05, 2021, 09:53:23 AM
Heh, I think temp changes are what are throwing my air sensors off. Get everything stable and take it outside and it instantly reads a different value. Not because there's H2S in the air, but because its gone from 20 degrees to 10.

Will probably need to build in temperature compensation but not all the sensors data sheets provide temperature offset info.

Also, have you noticed how hostile the Arduino forums are? I've never seen anything like it. Literally all questions have to be written in such a detailed way that takes way too long to do or they descend en masse to have a go at the poster.

And on the rare occasion they're polite, inevitably they start bickering amongst themselves.


I've not been on there in a long time, mostly I manage to get more immediate answers by either googling or my question is about a specific repository where I'll generally raise a question to the dev via github or their discord etc.. Reddit can sometimes be useful too, the esp8266 group is pretty good..

Re: Door open timer switch thingymajig
Reply #28 on: October 05, 2021, 11:10:09 AM
like Nige I don't have anything useful to add, but it looks good / glad it's working :-)

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