Introduction: DIY Tablet: Powerful, Easy-to-make, (relatively) Cheap [Part 1: the Guts]
Hi everyone! This is my first Instructable and I'm really excited to share it with you! Now, given that you are on this site or app, I'd guess that you'd probably have at least one idea that hit you like a baseball bat and then occupied the outer fringes of your neocortex ever since. This happened to me on the train one day as I was gazing at the screen tethered crowd, and I thought, "Hey, what if you could make your own tablet?"
I then proceeded to scour the internet for guides and 'how to's and came upon this great guide by Michael Castor detailing how he made his own tablet using a Raspberry Pi here. With flashy battery lights, a carbon fibre backing and a dashing walnut finish, the only things I wasn't particularly fond of were the Raspberry Pi and the difficulty in constructing it. I wanted something with a little (actually a lot) more kick to it that wouldn't cost three quarters of the project. So I turned to the Odroid U3 for several performance buffs and its similarly great community. The next step will further detail the performance.
Several things to note:
All prices are in USD unless stated otherwise
All prices and currency conversions are as of 2 Jan 2015
Step 1: Odroid Performance Comparison to 2014 Tablets
Enough of the unnecessary but poignant back story. Its time to put my money where my mouth is and show the numbers. I selected a couple of benchmarks based on a range of activities that one would do on one's tablet and benchmarked it against the best tablets at end of 2014 according to Techradar, and the Raspberry Pi of course.
- Geekbench - processor and memory performance (Higher is better)
- Peacekeeper - Measures online speed from browser (Higher is better)
Now, as you can see, the Odroid's performance is quite close to that of the Galaxy tab and is quite sufficient for my everyday tablet needs. While it may not exactly have the power of an iPad air 2, the total cost of the project is lower than that of the iPad and you'll get the cool, geeky bragging rights to say you made your own tablet.
Another point I should mention is that the Odroid U3's power consumption is just over 1A or at most 2A at 5V, which is pretty good to most power banks and the tablet's battery life.
Step 2: International Shopping!
A DIY tablet basically consists of 3 main things. A tiny computer, a touchscreen and a battery pack. Do note that all shipping costs are from the country of origin to Singapore, so costs might vary based on where you live.
You'll need to pick up the following things from this site: Hardkernel
1. Odroid U3 - USD65 - The tiny computer
2. RTC Backup battery - USD2.50 - Maintain system clock
3. Odroid U3 case - USD4 - for good measure
4. USB DC plug cable 2.5mm (at least 2 units!) - 2X USD1.9 - Used to connect the Odroid and the touchscreen to the battery pack. Difficult to find elsewhere.
5. WiFi Module 4 - USD14
6. 8GB SD/eMMC module U Android - USD8/USD25 - Whichever fits your wallet and attention span, eMMC is much much faster than SD. You could use your own SD card, but remember that 8GB is the minimum. Also, feel free to buy one that has a greater size if you want.
7. HDMI Cable(Micro, type D) - USD5.70
8. Shipping - USD30
The next place you'll need to visit is here: Chalkboard Electronics
1. 10" universal LCD with HDMI interface and capacitive multi-touch - USD134.95 - This module is unique as it requires a 5V power supply, whereas most others require 12V. This allows the board to be powered up by about any standard battery pack. Do note you can also buy the 7" option if you want, but not the 14" and 15.6" versions as they require 5.5V. Do also note that out of the box, single touch is supported and if you want multi touch, you will have to update the firmware and kernel as described in the chalkboard electronic blog.
2. Shipping - USD33.60
C. Your local electronics store
If you live in Singapore, I got all my stuff from the infamous Sim Lim Square.
1. HDMI type A to type C converter - SGD5/USD3.62 - The Chalkboard electronics Screen receives a type C HDMI input.
2. USB male to USB mini male - SGD3/USD2.17 - The Chalkboard electronics board uses a USB mini input from the Odroid to get touchscreen data.
3. 12,000mAh Battery pack with dual charging ports - SGD19/USD13.77 - The power supply for the tablet. The dual ports are needed to simultaneously power the Odroid and the Chalkboard electronics Screen via the USB-DC plug cable from Korea. Do note that some power banks cut power off when the Odroid and screen are plugged in (too much current drawn), so the best way to check is to bring the Odroid and screen down to the electronics store and test it in store.
Total cost (excluding shipping): USD257.51
Total cost (including shipping): USD321.11
Step 3: Putting It All Together
Here comes the fun bit! There is this certain mad scientist satisfaction derived from connecting electronics that you should begin to feel once starting this section. It helps to that no soldering is involved and all you need to do is simply connect one end to the other.
Firstly, start off by connecting the RTC backup battery and the SD/eMMC module to the Odroid.
Connect the HDMI cable to the HDMI type A to type C converter.
Connect the HDMI micro, 2.5mm USB to DC cable, WiFi module and USB to USB mini cable to the Odroid.
Connect the 2.5mm USB to DC cable to the chalkboard electronics screen.
Connect the Odroid cables to the Chalkboard electronics cables. You should have 2 USB type A cables not plugged in anywhere.
Connect these two cables to the portable power supply. If luck is in your favour, you should see the android logo on the chalkboard electronics screen within a minute. Proceed to grin like an idiot and skip to the last step.
Step 4: Troubleshooting
When I first made my tablet, I was tearing my hair out because it wasn't booting and I had no idea why. Fortunately for my sanity (and luscious hair), the Odroid community came to the rescue. A big thanks to gripped, odroid and joerg for helping me with my Odroid issues.
So based on my experiences, I wrote a full troubleshooting guide for newbies here: Ze complete Odroid troubleshooting guide
If you still can't get your board to work, I'd recommend simply posting your question in the Odroid forum. I'm sure that the fantastic community will be able to clear it up real quick.
Step 5: This Is Not the End!
What good is having something really cool if you don't get to show off? I'll be posting a guide on how to make a case for your new tablet soon! (I'm toying with the fibreglass & Pepakura method and might switch to 3D printing if it doesn't work)
That brings us to the end of this instructable, I hope you enjoyed reading or making it as much as I did. Thanks for stopping by! And if you have any further questions, I'd be more than happy to answer it in the comments section below! Seeya!