Sunday, April 26, 2015

Turning Samsung galaxy note 4 (SM-N910F) into a mobile pc - Part 1 - The idea

As technology advances, mobile devices are becoming more and more prowerful, with quad core cpu and up to 3gb of ram memory. Since the battery of my good old nokia n900 was getting weaker and weaker, i decided to move on get a new device with today standard specifications. However i was unable to find a decent one with a qwerty keyboard. I tried to look for a UMPC but those devices are no longer manufactured, they were replaced by tablets.
It seems like we will never see physical qwerty keyboards on mobile devices.
But then an idea came: if the major smartphone manufacturers will no longer build smartphones with qwerty keyboards, i will make one myself. More exactly modify one.
So i got a samsung galaxy note 4, because it has top specifications, and started to think on how can i add: a phisical keyboard, a regular size usb port, a desktop operating system (even emulated ones, if they are running at usable speeds).

- A hardware qwerty keyboard - I am thinking on making a slide mechanism from two cases and for the keyboard i already ordered this:

That is a bluetooth qwerty keyboard with a mose pad (the mouse pad will be really useful for the operating system). I was thinking on a verus slide case:

However this case is the thickest case i saw, so adding the bluetooth keyboard to that will make the phone very thick. I will have to search for thinner cases.

- The "normal size" usb port - this new smartphones seem to be so thin, that it is almost impossible to fit a regular usb port inside the phone

I also tried to fit a usb port in a samsung galaxy note 3, which is thicker than the note 4. However this seem imposible too

As you can see, unless i cut the anthena of the phone out, there is no room for the usb port.
Now going back to the note 4, the way to get the usb port is by using the verus case, which is almost twice the phone thickness

However i will wait for the bluetooth keyboard to arrive, and then i will see what cases to use, and where to place the usb port.

- Desktop operating system - In this case the note 4 seem to use its processing power quite good, allowing the usage of linux and windows. Here is a video of windows xp emulated using limbo pc emulator (you can search it on google, but you'll need to root your phone):


It is not very usable, but still the fastest emulated windows on an android device.
I also manage to run Linux Debian with xfce interface.

This one does not need root, and the s-pen realy do a nice job by simply hover the pen above the screen, you can move the mouse. 
I did not tweak any of this systems yet, to make the faster, i just installed them and leave everithing as default. I'm sure that with some settings i can get this systems more optimized for the note 4.

I am also thinking at a solar panel on the back (as i did on nokia n900). In this case, it should be easyer becase the note 4 supports inductive chargers, so it does have the power conectors already soldered on the back of the phone.

Saturday, April 25, 2015

A few modifications of the Nokia n900 smartphone

I always wanted a smartphone like a small computer. for that i wanted to be able to connect any usb device on the phone without any adapters, Since such a phone does not exist, i soldered a regular pc usb port into the phone.

The usb wires are connected to the usb test points on the motherboard.

 Also, the "normal" usb port came in the place of the lock/unlock switch, which i moved on the upper side of phone.

Here is a video with the usb port in action:

On the back of the phone i installed a solar panel. 

However the efficency of this solar panel is very low, so it would take a realy long time to charge the battery, but it's good to be there just in case. In this case i soldered two connectors from the + and - of the usb test points that connects to the pads of the solar panel which i sticked on the back case. Nokia dsigned the charging circuit in this way: in order to charge, the data pins of the usb must be "shorted", so i soldered a switch that is doing that, when i need to charge with the solar panel (you can see me using that switch with the stylus in the video). The battery is also soldered with wires to the pads, so i can reach the switch without turning the phone off. In this way i can also hot-swap the sim card (i tested and it is working). Here is the video with the solar panel:

The last modification is a hot-swap micro sd card slot soldered on the pads of the old one.

i did this becase i found very unconfortable to always remove the back cover in order to insert or remove the micro sd card. So i removed the card slot from an old lg phone and simply soldered it on pads of the original one. I cut a little space on the back cover, and now i can swap the micro sd card a lot faster and easyer.

You can see more of my mods of n900 here:

In spite of all being one of the greatest phones, nokia n900 is getting older, the technology is moving on realy fast with phones that have quad core cpu's and up to 3gb of ram. However there is still hope, the guys of maemo comunity are working on a new n900: the neo900. Here is the website:
I, however, decided to move on and get a samsung galaxy note 4. Now will i be able to modify it both hardware and software like i did with the nokia n900? Stay tuned for the answer!