Using the Raspberry Pi to Turn an iPad into a Real Computer, part 2: The iPad

In my last post, I talked about why I wanted to do this project, which was mostly about not wanting an old iPad to sit in a box with all my other crap. It was also about a clever use of a Raspberry Pi. While 99% of the work in this project is setting up the Pi, this post is about setting up the iPad.

Growing up the iPad
My daughter got the iPad when she was 4. We bought it refurbished from Amazon. As much as I dislike Apple as a company, and as a platform, the quality of their hardware is impressive. We put the iPad in a pink foam bumper case. It was subjected to all manner of child induced terrors: spilled milk, sticky fingers, being left to die in random places. Despite being 2 years old when we got it, and her using it for probably 5 years, it’s still in pretty good shape. The screen cracked in one corner.

I cleaned it up, and I put it in a cheap folio case.

The only real modification I made to the iPad was to install a Unix shell app called Blink. Blink has some essential tools like ping and ssh, along with the ability to map hostnames to IP addresses in a manner similar to /etc/hosts.

The app is $20 per year, it’s meant to be used for home automation, and includes a lot of that. If you aren’t into that you can just shake your iPad every day or two and keep using the app for free.

The iPad’s on screen keyboard doesn’t have some essential keys, like CTRL or arrow keys. If you are going to spend time in the Unix shell, you should probably have a hardware keyboard.

My wife has a Bluetooth keyboard that she uses to live-Tweet TV episodes sometimes. It doesn’t have a touchpad, it runs off of AAA batteries instead of being rechargeable, but it does have arrow keys. The F-keys (F1-F10) behave a little strangely, which I will go into more in the next post about configuring the Pi.

The most practical solution would be a keyboard with a dedicated CTRL key, arrow keys, and a touchpad. If I end up using this gear a lot, I might splurge on a cool keyboard.

I spent a little while shopping for 60% mechanical keyboards. Buying a keyboard is definitely outside of the “shit laying around the house” constraint. A retro-gray keyboard would give the iPad some cool Unix style. A 60% keyboard doesn’t solve the touchpad problem, however, and a lot of 60% layouts don’t have dedicated arrow keys.

The Raspberry Pi doesn’t have a built-in battery, so using it portably requires a battery bank. I have a small collection of batteries thanks to amateur radio and owning a couple of smartphones with terrible battery life.

The Raspberry Pi 4b requires more amperage than the previous models. I have plugged the Pi into the battery for testing purposes, but I haven’t tested how long the battery lasts with the Pi plugged in. These batteries can completely charge two tablets from 0 to 100% simultaneously, so I am pretty sure I can get several hours of use with the Pi. Of course, in a situation where I am charging the iPad and my 4G hotspot, that duration lowers significantly.

And now, the fun begins: Setting up the Raspberry Pi

Using the Raspberry Pi to Turn an iPad into a Real Computer, part 1: Prologue

This Christmas, we upgraded the kids’ iPads, and I inherited my daughter’s old iPad Air 2. I had an iPad years ago, but I didn’t like it.

I like tablets, I just didn’t like the iPad. Tablets fill this weird gap between a smartphone and a PC, where you can do what you do what you do on your phone (texts, memes, and games) only more comfortably. A laptop is best used when seated, preferably at a desk or table; it’s portable. The smartphone is great when you are out of the house or office and moving around; it’s mobile. The tablet fits into that middle space: seated but not at a desk or table, such as in bed, on the couch, on a long flight, or riding a train. Staring at a screen of any kind in a car for a long time makes me nauseous, so I prefer audio for car trips.

I also hate tablets because they come close to doing what a netbook used to, before 10 inch screens went extinct. (Yes the GPD Pocket is a thing, it’s also the price of a gaming laptop. I already have too many laptops as it is, without dropping 12 Benjamins on another one because it’s cute.) Netbooks are great for note taking in a meeting or class, or for doing light system administration tasks where you need basic networking tools like ping, ssh, or more serious tools like network scanners or wifi analyzers. Android tablets do ok in this regard, but the lineup of network tools for iOS are not great.

The problem with a tablet is that it isn’t a netbook. The problem with a netbook is that it a tablet.

Since inheriting this iPad has cost me nothing (well, I paid for it years ago) I am going to try it again. This time I am also re-creating the netbook experience using recycled technology that I already have. I am trying to create a portable (not necessarily mobile) computing setup that is smaller than a laptop, charges off of 5v DC, does Unix shit reliably, stores files and streams media without Internet access, and fits in my man purse. The theme of this project is “modular off-grid solar powered computing made with shit laying around the house.”

The essential difference between a tablet and a netbook is the keyboard. The dream is to have either a netbook with a removable screen, or a tablet with a detachable keyboard. Those purpose-built devices are nice, but they are also expensive. For this hand-me-down project I decided to kludge pieces together instead.

Using a tablet keyboard is usually pretty lame, especially a keyboard with no touchpad. Taking my hand off the keyboard to touch the screen is a major distraction. I had a touch screen laptop for years and rarely used that feature. I think I have a decent little Bluetooth keyboard somewhere, one with that ThinkPad nipple-looking thing. It’s probably sitting in a box with a bunch of broken tablets.

As much as I dislike membrane keyboards, they will be significantly better than typing on the iPad when it is propped up in that tilted landscape mode.

Off grid
Traveling with a laptop can be kind of a waste, especially when you end up not using it very much. Wasted suitcase space isn’t that big a deal anymore since haven’t been on an airplane in a couple of years. Anymore, the traveling I do is outdoor stuff like car trips and camping. Tech in these scenarios is great for keeping the kids busy when it’s rainy, cold, or on long car rides. We travel a few times each year to my in-laws lake house where there is tons of nature, but not much access to the Internet. Offline media requires the kind of storage that tablets are notoriously short on.

In the before times, when international travel was a thing, I used a cheap Andoroid tablet and a Chromebook. The Chromebook had a real keyboard and real web browser, while the Android could run arbitrary apps from the Google Play Store. The combination was a decent small toolkit. Between having kids and COVID, I haven’t gone over seas in several years. All that gear is probably obsolete now anyways.

I hate electronic waste, and yet I seem to produce a lot of it.

Shit laying around the house
This project began as a plan to reuse a hand-me-down iPad. I set the old iPad up purely to get access to FaceTime, and as I loaded my old apps on it, I discovered that it was still decently powerful.

I have also collected a few Raspberry Pi’s over the years. I have done maker stuff with them, used them to demonstrate things at 2600, including a Pi PBX one time as a proof of concept. They’re handy little things. As I get more into amateur radio, Pi’s come in handy for different digital and packet modes.

The Pi also runs off 5v DC, albeit at higher than 2a. This isn’t a problem with modern phone chargers and portable battery banks, of which I also have a couple.

Adding Solar
Amateur radio has taught me about the importance of charging batteries in the field. “Field rechargeable” is probably a better term than “solar”. Solar is more of a guideline. If something can charge from USB, you can probably charge it off of solar. If you can charge it off of solar, you can probably charge it off either 5v USB, or 12v car electrical. Wall and car chargers for smartphones are great sources of USB power, and in the family travel scenario, car and wall power make more sense. USB ports in computers can also charge USB devices, although they tend to do it very slowly. The Pi 4 can’t run reliably from a laptop USB.

I have a folding solar panel with a 12v power output and USB outputs. I normally use it to charge my portable solar generator. That’s a stupid name for the device. It’s just a big 12v battery, it doesn’t generate anything. I already have a collection of USB battery banks laying around the house, so one of those should run the Pi for a pretty long time. I even have a USB battery bank with an integrated solar panel, though it takes multiple days worth of good sunlight to fully charge it. I haven’t tried laying out the solar panel with the solar banks plugged into it to see how it charges, but I am hoping to try it out when the weather is nicer.

Stay tuned for the next installment where I get started configuring the iPad.