Smart Doorbell System - Part 10 - Complete Project Video

RE: Smart Doorbell System - Part 10 - Complete Project Video

shabaz — Tue, 30 Oct 2018 01:36:48 GMT

For a revision 2 PCB for the bell push, these are the enclosures I'm considering. Any alternate options welcome!

A 3D printed custom version would provide a lot of flexibility, but that can be a revision 3. For now, I wanted to use an off-the-shelf enclosure.

The problem is that most small bell or alarm push boxes are designed for the small old-school A23 sized 12V battery. But this project requires around 3V, and I'd like to use large non-rechargeable cells for longer life, and they would be ideally be a single non-rechargeable Lithium AA sized 3V battery, or two 1.5V AA or two 1.5V AAA batteries. So, space is needed for a holder or clips for the single or double AA, or double AAA.

Around 7mm depth is needed for the PCB (less is possible, but the microswitch needs a few more millimeters for the lever that will need to be implemented. The current PCB is about 77x28mm, and only a few millimetres thickness apart from the microswitch. The PCB could be reduced from 77mm to maybe 60mm if required, by expanding to 35mm width maybe.

These are the current two candidates:

Option 1:

I think it looks quite ugly (I'd rather a more classical shape) but it may be good enough to fit a couple of AAA batteries.

[View:/resized-image/__size/485x298/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-59257057-8c10-4a02-b09e-e89abbb8b58d/8400.contentimage_5F00_188017.jpg:485:298]

This is the other side of it, and I think it could be possible to fashion a plate to connect to the rear to attach to a wall, even if that was with foam tape to the plate screwed on the wall. The battery will last long enough that foam tape wouldn't need replacing often:

[View:/resized-image/__size/400x376/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-59257057-8c10-4a02-b09e-e89abbb8b58d/3632.contentimage_5F00_188018.jpg:400:376]

The enclosure would need spray-painting to blend in, i.e. spray it white or something.

Option 2:

This too looks ugly, but maybe less ugly. It is near-similar size but 10mm wider than Option 1. The cutout ellipse is great for an LED.

[View:/resized-image/__size/494x350/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-59257057-8c10-4a02-b09e-e89abbb8b58d/2146.contentimage_5F00_188019.jpg:494:350]

This enclosure would need spray-painting too, although it does come in a more acceptable color than black:

[View:/resized-image/__size/488x321/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-59257057-8c10-4a02-b09e-e89abbb8b58d/2654.contentimage_5F00_188020.jpg:488:321]

Option B enclosure is slightly unusual, in that it is 3-part, and so I believe has less room inside than Option 1, despite overall being 10mm wider:

[View:/resized-image/__size/620x392/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-59257057-8c10-4a02-b09e-e89abbb8b58d/2158.contentimage_5F00_188021.jpg:620:392]

Both options are not small, they are 120x45x22 and 120x55x22 outside dimensions, and I still need to order them to examine closely. I think the size is still reasonable for a smart bell push though. And leaves some flexibility for adding more features like a display or buzzer.

Both options cost about $5 each.

RE: Smart Doorbell System - Part 10 - Complete Project Video

stevesmythe — Mon, 29 Oct 2018 11:41:40 GMT

A very interesting and useful project for others to learn from. I am always impressed at your circuit board design skills.

Would it use too much energy to have a small piezo sounder on the bell-push end? I'm thinking that the person pressing the bell needs some audible feedback that it has worked (I know there is an LED but the visitor might not appreciate what that means). In some houses (e.g. those with an enclosed porch), the visitor wouldn't be able to hear the sounder from outside the house. It would also act as a quick debugging check that the bell-push end battery has enough power left for a bluetooth transmission. My own wireless bell-push blew a capacitor and wasn't working and that wasn't obvious for a while, until people started hammering on the door!

RE: Smart Doorbell System - Part 10 - Complete Project Video

aspork42 — Sat, 11 Aug 2018 16:01:25 GMT

What would you estimate the BOM cost for 10 units? I was thinking of using the pushbutton type setup as a home security monitoring device - i.e. window sensor. Instead of a pushbutton, it would be a reed switch & magnet and look for any transition to report. I would need to build up about 20 units; and would possibly use a single sensor and dual sensor unit (for two windows right next to each other). I've seen other units that cost like $40 each, so that is pretty cost prohibitive. If these are in the area of $10/unit it becomes much more feasible.

RE: Smart Doorbell System - Part 10 - Complete Project Video

aspork42 — Thu, 26 Jul 2018 17:58:26 GMT

Hey - Congrats on winning! Very well done!

RE: Smart Doorbell System - Part 10 - Complete Project Video

aspork42 — Wed, 25 Jul 2018 04:50:08 GMT

Really nice looking final product!

My baby monitor has the "child" unit as always requiring DC power, but the "parent" unit uses a tiny DC barrel jack and also 2x AA batteries. The parent can, say, slip outside to the back deck or over to the neighbor's house and carry the unit with them to keep an 'ear' on the child. The unit switches automatically over to the batteries when unplugged. So your unit uses a rechargeable battery and is better than mine!

One other feature that it has though, is visual and audible (LED, and sound) indications if the parent unit is unable to establish communication with the child unit. So if we walk too far away, it will start beeping to indicate "out of range".

I love you comment in the video "It should last about four years, which is OK" [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-59257057-8c10-4a02-b09e-e89abbb8b58d/contentimage_5F00_1.png:16:16] (Paraphrasing, of course)

My first battery powered project (very similar to this but with ESP8266 + Arduino ProMini) lasts only about 6 months, or ~180 button pushes... Need some more optimization!!!

RE: Smart Doorbell System - Part 10 - Complete Project Video

DAB — Sat, 21 Jul 2018 17:36:28 GMT

Nice build.

DAB

RE: Smart Doorbell System - Part 10 - Complete Project Video

genebren — Sat, 21 Jul 2018 16:20:42 GMT

Very nice wrap up on your design challenge project. Everything turned off great (PCBs, code, sound effects, etc). What an amazing ride it has been through your development process. There were so many useful nuggets of information presented, that I will have to go back (again and again) to re-read and re-learn the lessons that you presented.

Thanks for the great information!

Gene

RE: Smart Doorbell System - Part 10 - Complete Project Video

mcb1 — Sat, 21 Jul 2018 05:25:20 GMT

Well done.

It's a lot of work, and I'm betting your're glad it over.

A simple suggestion is to look at wireless charging.

I used something very similar in the Beyond_the_phone challenge

Wireless Challenge .... the other bit -2

Simon wrote about it here, and if you look at the picture they aren't very large

The Illuminated Beer Tap

https://www.fasttech.com/products/0/10007722/1671100-universal-qi-inductive-wireless-charging-receiver

This means the unplugging and plugging is eliminated.

Mark