I want to ditch my laptop when I'm away on work trips. I do 99% of my daily computing on my iPhone XS Max either using the native iOS or via remote desktop to my Raspberry Pi and Windows gaming rig/server back at home. To date, I've been using a fold-out Bluetooth keyboard and a stand for my iPhone, but it's quite a clunky solution. A few months ago I saw an advert for the Gemini PDA by Planet Computers. It uses elements very similar to the old Psion 5MX to offer an all in one phone/mini laptop solution. I loved my PDA back in the day, but as a self-confessed Apple Fan Boy, and having just bought a new iPhone XS Max 256GB, I couldn't justify spending another £500+ on this new toy. Then I remembered, I still had my old Psion 5 lying about somewhere. Luckily I found RasmusB's (https://hackaday.io/RasmusB) fantastic Psioπ project and USB keyboard adapter...
The basic premise is to create a clamshell style case for the iPhone XS Max with an integrated keyboard using various components to enable the old Psion 5 Keyboard to work via Bluetooth.
I wanted to create a mini laptop/PDA/phone in the style of the Project Computers Gemini PDA, which is built on an Android base.
As I have continued designing the project I have also now integrated a QI wireless charger that will go behind the cradle that holds the iPhone. This is connected to a 5000 mAh battery pack which provides charge for the iPhone, as well as powering the Bluetooth module. I have since taken this one step further to make the power bank itself wireless, by adding a wireless charging receiver to it.
Oh no!! My wife was cleaning the kitchen where I've been working on the keyboard and knocked off the USB Keyboard Adapter and accidentally trod on it! It's completely broken, so I've had to order a new one from RasmusB, so the project is on hold for a few days until that arrives from Sweden. In the meantime I've ordered some smaller components to maximise the space inside the shell.
Having struggled and eventually given up on using the Bluetooth adapter yesterday, I was eager to move forward with the new plan to simply use a lightning cable to connect the keyboard to the iPhone with a USB to Lightning adapter.
Next on the to do list was to get everything neat, tidy and encased. I originally planned to build my own wooden case and then cover it in a aluminium veneer. It very quickly became apparent that A) My woodworking skills are pretty dreadful & B) The original power bank I'd purchased was going to make the keyboard far too bulky. I therefore switched out the power bank to a lower powered one I had lying around, it should still do the job, and more importantly it's a lot smaller. At this point I also decided to utilise the second USB port on my USB hub. I opted to add a female to male extension, so I can use a second USB device on my iPhone if I need to.
After about three hours or so I had a finished wooden case, but it was huge! The vinyl I had selected for the veneer also looked APPALLING! So, I ripped everything apart and decided to start again. This time I decided to utilise the old case from the Psion 5. I had gutted it when I removed the keyboard and since I had switched out the power banks, I now required considerably less space.
After another couple of hours of experimenting with a layout and removing the casing for the USB hub and power bank, I finally had a workable solution. The only issue I faced was the fact that everything was just a little too thick to fit in the original case. Not to be beaten I decided to accept the slight gap between the case and the keyboard. I had quite a bit of adhesive backed foam, and decided to use this to create some bumpers that would seal the case and the keyboard together and also fill the gap. I was happy with the results.
Unfortunately I hadn't tested the QI wireless charging receiver before putting everything together. It just wouldn't work through the Psion case. So, once again I took everything apart, removed the QI receiver, stuck it to the outside of the case, and then put it all back together again. In the process I broke a connection on the USB hub and ended up having to solder that back together as well.
Finally though, I had everything sealed up and working after about 6 hours of work. A day well spent! Next it's on to the cradle for the phone along with the QI charger I intend to install into that.
I've been doing some pretty rigorous testing over the last few days trying to get the USB adapter to interface with the Bluetooth adapter. No matter what I do, I can't get the two to interface. At first I thought this might be a power issue, and so I added a powered USB hub to see if that would help. No luck. Next I tried hard wiring the power bank that I intend to use for the built in QI charger. This time both the USB Keyboard Adapter and the Bluetooth adapter were powered up and obviously responding, but they still weren't talking to one another. Having tried the combination on a variety of different platforms (iPhone, iPad, MacBook, PC, Raspberry Pi) and still having no luck, I admitted defeat. Bluetooth just isn't going to be an option for now. I don't know why, and if anyone has an ideas I'd be interested to hear them!
So, what to do next? I decided to purchase an unofficial Lightning to USB Camera Adapter from Amazon for about £12 in order to connect the USB Keyboard Adapter directly to the iPhone. Thanks to Amazon's same day delivery it was in my hands that evening. I hurriedly connected it all up, plugged it into the iPhone and..............it didn't work. I got an error message on the iPhone saying that the Arduino needed too much power. So, out came the powered USB hub again! This time it worked. This is a long known work around for the power issue on the iPhone and iPad. The only issue being the size of my USB hub. Some redesign would be needed. But, at least I could finally type on the iPhone using the Psion keyboard. It would just need some refinement.
The first step has been to teardown my old Psion 5 to harvest its excellent keyboard. This was made very easy thanks to the guide by Peddy on iFixIt.
With the keyboard now in hand, it was time to connect it to RasmusB's fantastic USB Keyboard Adapter for Psion 5/5MX. Before starting the project I had looked to order the adapter, but Rasmus said it was currently out of stock. After about five or six weeks I got a Tindie alert saying he had another batch available, and within seconds I'd placed my order. It arrived in the UK from Sweden after about 5 days, which I thought was exceptionally fast.
The adapter is tiny with a port for the keyboard and a Micro USB port. It comes with the software preloaded on an ATMEGA32u4 CPU and is pretty much plug and play. I wanted to update the firmware and change the key-mapping, but having little experience with Arduino, I struggled. Luckily, Rasmus is a remarkably friendly guy and was on hand to help me out by giving me step by step instructions via email. Thanks Rasmus!
I tested the keyboard and the adapter by plugging them into both my MacBook and my PC. It worked perfectly on both! Next it was time to try and make it Bluetooth compatible....