Two dusty tablets were converted into electronic photo frames and smart control screens, and the third option was to persuade them to quit.

During the cleaning on November 1st, two tablets were found in the drawer.: An iPad mini 2, as I wrote before Old devices slow down WiFi The machine that was used in the cutscene was a 13-year-old machine. The system stopped at iOS 12. ； I bought a Xiaomi Mi Pad 4 in 2018 with a 10.1-inch screen. I bought it for my children to take online classes. I kept it under the coffee table for two years when I was busy with schoolwork. At that time, the two screens together cost less than 5,000 yuan, and I couldn’t just throw them away. I spent a weekend looking for jobs for them, and tried out three positions. Two screens were put on the wall, and one was returned to the drawer. Write down the process and pitfalls.

Let’s get a feel for it first. The foundations of the two tablets are very different.

Don't think that "they are both old tablets". When it comes to renovation, the two machines can do completely different tasks. There is only one watershed: Is the system still able to install the current App? .

Xiaomi Mi Pad 4 is based on Android 8.0 or so. Official updates have been suspended for many years, and many new versions of apps in the app store also indicate that they are incompatible. But Android has an advantage. APKs can be installed directly. Gadget apps such as photo frames and launchers have very low system version requirements. The ones I picked later can all run on Tablet 4.

iPad mini 2 is miserable. The threshold of iOS 12 blocks out most mainstream apps - the new version of Mijia cannot be installed, and it crashes when installing the old version. In the end, only Safari and the system's built-in clock are the only ones that can work stably. So I had a hunch before I even started.: This machine can only do "things that web pages can do", and it turned out to be true later.

By the way, the screens of both units are LCD. This point will be mentioned again when we talk about the pitfalls of screen burn-in. It is the inherent advantage that they can be "always on".

first position: Electronic photo frame in the entrance hall, with 40,000 photos placed in rotation

All my family photos are on the NAS and have been backed up automatically on my phone for four years, more than 46,000 photos and 186GB. I have written about the backup route before . The photos lying on the hard drive are as if they were never taken, and they cannot be viewed twice a year. The wall in the entrance hall has always been empty. It costs four to five hundred to buy a large-screen digital photo frame, and it only reads SD cards--the Xiaomi Mi Pad 4 has a ready-made large screen.

The solution is simple. There are a lot of photo frame apps on Android, but I only recognized two words when I was choosing them.: WebDAV or SMB . It can mount the photo album directory of the NAS, and the photos will be rotated automatically. New photos can be played automatically after being backed up, without me having to move files. Those who only recognize local photo albums will be eliminated directly. 186GB cannot be crammed into a tablet and there is no point in it. After hanging it up, I set the carousel interval to 10 seconds, added a transition effect, lowered the brightness to 30%, and automatically turned off the screen from 10pm to 6am - it is a waste to keep the photo frame on when no one is looking at it.

It worked better than I expected. When the elders come to the house, they see photos of themselves visiting the park displayed in the entrance hall. It is much more intuitive than flipping through the photo album on the mobile phone. ； The children have to look for their own photos on it every now and then, which is equivalent to forcing the whole family to go through the inventory in the NAS. This screen is now the “home appliance” with the strongest presence in the home.

second position: Smart control screen in the living room, saving hundreds of screen costs

I have more than 40 smart devices at home. I've done the math on the network. , but there has always been something awkward about it: The control is all based on your mobile phone. If you want to turn on the light when you enter the door, you have to take out your mobile phone, unlock it, and find the app. Xiaomi's own smart home screen costs hundreds of dollars. To put it bluntly, it is a customized Android screen - so why don't I make one myself?

Xiaomi Mi Pad 4 runs on the Mijia App, which is a native ecosystem. When installed, it becomes a large-screen console, and all devices in the house are arranged on one screen. What really needs to be done is the three steps of "turning it into a dedicated screen":

The first step is to turn on "Keep awake" in the developer options. The screen will not turn off when charging. This is a prerequisite for always being on. The second step is to use the system's built-in "screen fixing" function to pin the Mijia App to the foreground. The elderly and children at home cannot exit even if they press it randomly. Pressing the return key will only prompt you to press and hold the task key to unbind it. The third step is to adjust the brightness to about 20% and hang it on the wall of the living room so that it is not dazzling at night.

Tablet 4 just climbed up from under the coffee table and became a fixed console in the living room. When I enter the door after get off work, I click on it and a set of curtain lights are fully opened. ； When I go out and click on the away from home mode, it’s much faster than touching my phone. I would say this is the most cost-effective position in the renovation of old flat panels - the replacement is a finished product worth hundreds of dollars, and the cost is zero.

third position: Bedside monitor screen, iPad mini 20% off in the first step

There is only one iPad mini 2 left. I originally planned it to be a bedside monitor screen: Hanging the real-time picture of the home camera, you can watch all the movements in the child's room on one screen, and it can also be used as a clock. This idea itself is fine, I’ll take it Turning an old mobile phone into a surveillance camera When I was working on it, I thought that a pair of acquisition terminal and display terminal would be a self-made security system.

As a result, it got stuck on the first step.: The new iOS version of the monitoring app requires iOS 13 as a minimum, and the mini 2 stops at 12. Go to the web version? The web pages of various cameras have either been closed long ago, or they only provide playback but not real-time streaming. I struggled all night. After installing the old version of the app, it crashed. The RTSP address of the camera that Safari directly connected to was useless - Safari on iOS 12 did not even recognize many new certificates.

The last job it did was: Plug it into the bedside charging stand and use it as a big clock that stays on all night. Safari opens a clock webpage, which is barely enough. To call it a "position" is a bit reluctant. A twenty-dollar electronic clock can do a better job. So my conclusion is very straightforward: The iPad, whose system is too old, is basically useless for other positions except for web pages, so don’t have high expectations. . It is now considered a "backup in progress", and one day it will be urgent to use a lightweight device to support it.

Before going up the wall, deal with the three pits first

Hanging an old tablet on the wall with power on for a long time is completely different from using a tablet in daily life. There are three pitfalls that I have thought about in advance and checked the information. Don’t skip these steps.

The first is the battery. Leaving the lithium battery plugged in for a long time and generating heat at full voltage is the number one cause of bulging. These two old machines are eight years old and thirteen years old, and the batteries have already reached their age. The old system doesn’t have the new feature of limiting charging to 80% (the iPad’s charging limit is only available in the new version of the system). My method is crude but effective.: Plug in a smart socket, and the photo frame screen will be powered off at 10pm and powered on at 6am. It will be completely powered off for eight hours a day. ； The control panel is set to cut off power from 2 to 5 in the morning. In addition, just like the old mobile phone set, touch the frame once every two or three weeks. If the edges are warped, soft, or the screen is pushed up, any one of them will be deactivated immediately. , bulging batteries are non-negotiable.

The second is screen burn. Why do I dare to keep these two lights on? Because they are all LCD screens, LCD displays static images for a long time, leaving at most a recoverable afterimage, which disappears after changing the screen for a while. If your old tablet has an OLED screen, you need to be more careful.: Keep the brightness low, set the status bar to automatically hide, and don’t let the carousel interval be too long so that the pixels don’t stay on the same picture. If you buy a new tablet and want to use it as a permanent screen, you should give priority to LCD. This is the hard truth.

The third is power supply and heat dissipation. The length of the charging cable is the radius of the screen. First measure the distance from the wall socket to the hanging point before buying an extension cable. ； Use the original charging head or a regular one with an output of 5V2A. Don’t settle for a 9.9-dollar charger. For heat dissipation, do not stick the tablet to the wall, leave a gap behind it, and do not hang it toward the wall where it will be hot in the sun in summer.

Before I get the electricity bill The metering socket for measuring electricity bills Tested: Tablet 4 carousels photos at 30% brightness, with a reading of just over 2 watts. It consumes about 0.05 kilowatt-hours of electricity a day and a night, which is less than 1.5 yuan a month. Don't worry about this account.

Take your seats and give me an order.

Not every old tablet is worth saving, let’s be clear first:

The order of doing it is as follows:: First, fully charge the tablet and leave it for half a day to make sure it does not lose power or generate heat. ； Install the app and try out the positions. Do whatever you can do. ； Then buy a bracket and a smart socket, it only costs a few dollars ； After hanging it on the wall, keep an eye on the battery and heat in the first week. ； Only when everything is stable can we truly be "re-employed." I am already familiar with this set of old equipment. I have modified old routers, old optical modems, old set-top boxes, and old mobile phones. How to change the old optical modem and A way out of old set-top boxes We have all written that tablets are the most worry-free among them - there is no need to disassemble or refresh the phone, just pick the right position and you're done.