Hide Away Rolling Pantry

Internet of Things Phone Smart Charger

I pre-ordered one of the Samsung Galaxy Note7 phones. The ones in the news recently for being an explosion hazard.

I love the new phone – pocket computer really, the way I use it. I wasn’t about to give it up over some silly thing like spontaneous combustion.

I had read that Tesla runs their car batteries between 40%-80% for normal use to maximize the lifetime of their very expensive car batteries. I figured that cell phone batteries would benefit from similar treatment. A bit of research generally confirmed this, with http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries being the most concise write-up. The first half basically demonstrates that you can get the same amount of total power to flow through the battery regardless of how much you charge it – summed over the total life of the power draw in the data tables. The 2nd half is more interesting. It says that high voltage charges and heat shorten the overall lifespan of the battery.

The Note7 is a sealed phone wihtout a replaceable battery. I can’t pull my usual trick of replacing the battery after a year of abusing it.

Heat seams to be the trigger for the phone explosions. So I can make my phone more safe, and make it last longer by managing the top voltage and heat in the battery.

I can do this.

I bought a wireless Qi charger to charge the phone because it charges slower. The fast charger can charge the phone crazy fast, but it gets HOT when it does this. Hot is bad. Thus, slow is good. The wireless charger will also reduce wear on the USB C port. A nice side benefit. No phone explosions while I sleep and burn the house down – this is a good thing.

I bought a Belkin WEMO wifi controlled outlet. It is If-This-Than-That (IFTTT.com) capable so I can control it from my phone. There are other smart plugs available that will work, this is simply the one I could find in a store that I could verify would work with IFTTT.

I configured IFTTT to have 2 different actions. One for turning the WeMo on, the other off. I set these up as Maker Channel triggered recipes. There are other triggers that you can use such as email or SMS, but I am a web developer, so web-based triggers are a natural fit for me.

Image of The Rules set up in IFTTT
The Rules set up in IFTTT
Photo of the IFTTT Off rule
The OFF rule in IFTTT. It uses the Maker Chanel for the trigger, which means a web request will trigger this. It turns off the WeMo controlling the wireless phone charger.

I installed Tasker on the phone and configured it to monitor charge state and battery temperature.

I created 3 tasks, one to turn the charger on, and two to turn it off.

photo of Tasker rules
The rules in Tasker to control the phone charging.

The ON trigger looks for the battery to be below 80% charged, and below 35 degrees Celsius. This will make a request to the IFTTT.com Maker Chanel URL for ON.

One OFF trigger looks at the battery temperature. 35.1 degrees or higher. The other OFF trigger looks for the battery charge to be 90% or higher. These two both make a web request to the IFTTT.com Maker Chanel OFF URL I set up.

So now as the phone battery heats up or gets close to full, the phone tells the charger to turn off. I let the phone have a 10% charge window so I am not toggling the switch and charger on and off all night long.

Tasker with both OFF rules turned on. The phone is both charged to 90% or more as well as running hotter than I would like.
Tasker with both OFF rules turned on. The phone is both charged to 90% or more as well as running hotter than I would like.

I also programed the WeMo to turn itself on a little while before my alarm is set to go off. This is to let the battery be closer to 90% charged rather than 80% charged when I wake up. I haven’t found the right time for this yet. I still need to play with it a bit.

I know there are other ways to make a smart phone charger. This is what I came up with. I will be getting an additional smart plug and building one for at the office so I don’t over-charge my phone when at work. I will try a different brand likely to see if I can come up with a cheaper way.

I few months back I bought a Galaxy Note Edge on eBay

It came with several case options which I would have never bought myself, but they are interesting. The one that I thought I wouldn't like but fell in love with is the flip-case. Granted, I was not fond of the white case, but the functionality was more than I would have expected. It just missed one feature.

Wireless Charging.

I LOVE wireless charging. Almost as much as I love the fast-charger that came with the phone.

There are hacks to get wireless charging into a flip case. But I would need to order a wireless charge back plus a new black flip case. Because I really don't like the white. If I am going to do the work of hacking something, I want it the way I want it.

So I made my own.

I still bought a wireless back – it's crazy the cheap prices on eBay for some stuff. And I spent a good chunk of money at Tandy Leather. More than if I would have gotten a 'real' case, but I got stuff that will allow me to make exactly what I want.

In album Galaxy Note Edge Wireless Flip Case

The phone flip case. The hole in the flap is so I can turn the cover all the way around and take a photo. A feature that the ‘real’ flip case doesn’t sport.

The Note Edge uses a quick charger, which is AMAZING… if you have the charger with you. So I bought a 110v AC and a 12v DC charger.

You can get a wireless charging back cover for the Galaxy Note Edge, or a pretty nifty flip case. But not both features in one case. So I bought some bits and pieces from Tandy. Green leather, rivets, a belt clip, a magnet, tools, etc.

The flip case is ‘smart’ in that it talks to the phone. I have no idea what it says, but most people who are doing this mod are tearing apart both cases, and putting the wireless charging into the flip case. I don’t like the color of my white flip case that came with my eBay phone.

So I attacked my brand new wireless charging back cover with my drill press. I al less than keen with how I ended up with holes. I need to mark them before I drill. Eyeball isn’t good enough.

Lots of holes in my new case.

Holes all the way around.

The green leather is much darker looking to the eye. But this is what I am going to sew onto my phone case.

The front cover needs on the flip case needs to be stiffer. I happened to buy just what I needed when I bought my back cover. The plastic that the cover came in! Re-use all we can, right?

Stitching the leather onto the case was pretty easy. This corner proved difficult though. I ended up super-gluing the edge of the leather down to the plastic. I think the leather is stuck as much as stiffened up so it doesn’t come away from the plastic.

This is basically a cut-to-fit type build. The holes are cut after I sewed one end on.

The speaker has a lift to it so there is an air-gap between the phone and the table so you can hear the speaker. Clever!

The fake plastic leather or the real leather?

Guide lines for cutting based on tracing of the holes.

Leather glue all over the place. I am not sure if I like this type of glue.

All glued and stitched once.

I think I just had an invention idea for an internet of things Oven

Stick a borescope or two into an oven so we can watch what's cooking. Cell phone to monitor the image, you can tell if the item is done without opening the oven door from another room when the timer goes off.

Add a vent to the outside, and you can trigger a speed-cooling cycle by venting the oven heat out of the house. Now we can 'turn off' the oven from the other room and not need to remove the item cooking from the oven immediately without risk of burning the food.

Add computer vision and now you can set a timer for the browning of the item. If you want it golden brown, you can time for that. A little extra smarts, if you are in the kitchen, it triggers at the shade, if you are further away, it can trigger a shade lighter.

Perfect pizza, bread, and muffins every time!

Thoughts?