Acronyms: CT = Cubietruck DPF = Digital PhotoFrame RPI = Raspberry Pi TFT = 7" TFT display
Hi Everyone! I'm back!!
Now for (maybe?) the final chapter of Cubietruck chronicles, because some things changed and seems this time for good...
After a few months of working well, the DPF started to (once again) fail... The image on the screen started to shake and move like some kind of interference, but it wasn't. Something like this:
I tried different cables, input sources, but in the end it was the VGA to RCA video converter. After wasting a lot of time trying to fix it, I realized this actually presented an opportunity, because...
1- To buy a new or even better video converter like HDMI to RCA for instance, would cost me the same as a new RPI 2 (sadly, at least that's it in my country). 2- Buying a new RPI would give me the chance to try the new model which I was hopping to. 3- By replacing my old RPI would left a spare board with native RCA video output to hook on the TFT monitor and that way build a new DPF. 4- CT would suit perfectly as an Android TV set on a 24" non Smart TV, and that way make it "Smart". And that way make a much better use of CT, not just a picture album...
Now let say a little bit more about #4 since it's more of this board's concern. Items 1-2-3 will be for another day's (and board) topic...
As for hardware, I just get rid of everything but top and below acrylics and On/Off button. Just back to basics. But I have to add a little piece of plastic between CT and top acrylic to make pressure over the board and that way avoid any unwanted disconnection or memory error as in the past.
In short, no more fancy stuff... almost like in the beginning. But with an extra: a mini wireless keyboard that will fit just great with CT and that way have remote control of Android.
To continue on this, another step would be to add a power button bigger than the onboard power button which is too small to handle (even with Ewell case).
So I soldered two pins on the two holes located next to the onboard power button and from there I attached a push interruptor. It has two states, push once to close, push once more to open.
This was preferable to a push button because despite it will be needed to push twice to turn on or off CT, still will be easier than holding the button for a copule seconds, specially for an older person.
Here the pictures on how the button and VGA to RCA conversor were mounted on the acrilyc case:
These are pictures with the 12V fan attached to a side of the case, to push hot air away from CT and the bottom of the VGA to RCA conversor:
Here doing the final tests before to move it to its final destination:
CT is currently located over a computer desk, hidden behind an All in one computer. While the TFT is located nearby CT, on a shelf where former DPF was placed before. After booting on Android desktop and start XMBC, it has 1 minute of delay until slideshow screensaver finally starts, and 15 secs between random pictures.
CT can be turned off by pushing the interruptor, this action triggers a shutdown of the Android system. And here a video showing how it's finally working (click to enlarge):
As a conclusion, I have to say that no matter how expensive this may look, in the end it has been a cool experience that took a year to be completed (considering from the moment I bought CT on november 2013 until now).
I also hope people have not been offended by this article, I now most of you are Linux fans and you hold high expectations on cubieboard products, specially CT since it is a product designed for much more interesting things than just a dumb DPF running Android...
But this situation is much better than keeping a u$s 100 paperweight, as it was until I came up with this "crazy" idea. In any case I can go and rescue CT anytime if needed, the only thing is to bring a better DPF to replace it...
But I have to thanks CT for all the good and bad moments. During this time a learned a lot from CT, from compiling driver modules on Linux to debug through serial port. I hope you also have the fun of your lives with this product, or at least to have more luck than me!!
It worked well for a long time, until a few months ago it didn't start anymore. After a quick review I found the 5V wall charger was the problem. Since I had the original CT PS without being used at that time, I could spare it and I replaced the broken DPF wall charger. So far so good, a happy mother again...
Then while I was recently tinkering with CT and the Lapdock, she told me the DPF failed again. My first thought was a PS failure, but in that case it will be a big issue since the original DPF PS was 5v and only 650mA and CT PS is 5V 2A, meaning much more amps than needed. If this PS also got burned then the DPF had to be a real electricity blood sucking crap...
But when I tested the DPF I found this time a change of PS was not the answer. I opened it to see if there was something to do, but the circuit is quite compact indeed, very interesting for such small device. Just two little boards with everything, one for processor, memory and lcd interface all integrated and a little one with a 5 keys keyboard for setup and stuff. Nothing else. So if there were something fried it will be much difficult to me to find it...
In the meantime I took the chance to test the original CT PS and add CT to Lapdock and the other project all together. The CT PS was OK. Well, here I was thinking on one side how to fix the DPF and on the other what to with CT, since there was no enough room for 3 boards on my project... And suddenly it all made sense. Why couln't I use CT to build a DPF and replace the brown one?
But I didn't want to spend much money on that, I wanted to help my mother but if this would be an inconvenience it would be better to tell her to buy a new DPF. Nevertheless, DIY calling is much stronger and I wanted to do something about it by my self.
So the next step will be to find a cheap display for this project. And it turned out I already had one... From the other project I had a TFT composite monitor that I replaced by a Motorola Lapdock for Atrix. And a quick comparaison revealed they looked very much alike, at least in size:
OK, at this point you have to be thinking "WTF? Are you crazy? Why would you pay for something that it is already included in RPI?" "Why don't you use the RPI as it was intended in all the listed projects for a DPF with a RPI, instead of trying to reinvent the wheel?" And yes, that would make sense but it turns I'm not crazy... Or am I?
Anyway, I was closer to convert CT into a DPF than a RPI which was already working, assembled on a case with a system in place. And from my point of view, CT time had been passed. It was out too much time, and I already moved onto a new project to replace it, so there was nothing left for CT, just maybe a spare part. In this way it would fulfill a purpose, and would make my mother happy again, she loves her pictures collection.
With that in mind I proceeded to do some tests. First it would be needed to flash CT again with VGA Android image: http://dl.cubieboard.org/software/test/ct-android-factory-VGA.img.gz It worked like a charm, with one little problem. Due to there was hot wheater here, I noticed CT started to heat as well and eventually to turn off or restart.
And I plugged the CT USB power cable to one of the USB ports on back of the Lapdock. The only inconvenience was that when the lid was closed, power on the USB ports also got cutted and CT was shutted down without any warning... Just after open the lid againt CT started, meaning Lapdock USB ports remained off when the lid was not fully open...
Here some pictures while testing the stand alone mode (click to enlarge):
That would allow a project to use the USB port designed for Atrix cellphone, which when the lid is getting closed it just cuts power for a second and starts again once fully closed. This is not an inconvenience for a cellphone, but without any batteries CT still was shutted down and restarted as soon as the lid touched the keyboard.
But first I tested the cable, with no luck. CT seemed to not have power enough to work, as soon as it started to boot, it just power off inmediatly. Then I added a USB extension cable modified for my other project, with the 5V line cutted to avoid backpower on the CT USB ports (as also is explained on Adafruit video):
If this worked, eventually I would do the modification directly to the PSP cable. But didn't work either. The only way it worked was plugging the mini USB portion directly to CT OTG port, seems that reinforced somehow the power needed to boot.
That was not the expected because in that way USB port data for cellphone on the Lapdock was cancelled and the keyboard and pad wouldn't work either. Probably was a cheap cable, then after trying different configurations with no results, eventually I gave up.
But I was surprised when I also attached a Sata disk and it worked without problems, just with the power provided by the USB port on the back of the Lapdock:
As long as the lid remained open, it wouln't be any problems. But then CT wouldn't act as real laptop, right?
The only problem will be the keyboard and pad, because I have a USB swith with only two connections. But for testing purposes I could unplug Raspberry Pi USB cable and use it on CT. Other way was plugging a USB mini mouse to CT, and also a mini keyboard that I wasn't using anymore.
So here is a video of the "three amigos" working together... (click to enlarge)
If you look closely on the video you will see there is a lot of handling and you need to push hard to finally fit inside sata disk and cable. The back cover simple won't stay in position until be screwed.
First my CT just didn't boot. I saw some lights on, but they remained fixed, Android logo also freezed... I tried a few resets but nothing. At one point it managed to boot but it didn't go too far, monkey was also freezed... Each reset made things worse, until stop booting.
I opened the case and extracted everything out and put it back to the acrylics, then flashed CT with Android, everything worked again. I decided to call the night and leave it for another day, that was enough for now. When I tried again but this time without the disk, things were the same. Same deal. Until things went south...
After that I was never again able to boot CT, nor flash it again. With any distro. I expended a month trying to fix this, during the same I was asking everywhere and to everyone about this problem.
I also thank to all the people that gave me their support during the past months, like Gul or @lex and tydaikho when I stuck around figuring out how to solve this weird problem. From time to time I tried to flash CT again, with no luck... the process always stopped at some point, sometimes didn't even start.
I wonder if this wasn't actually a blessing because there are number of reports of heating problems because sata disks take high temperatures due the confinement, and even if this would have worked, probably my disk would have been fried eventually.
That's why I planned to extract Sata disk and put it outside in a base for the case, made of the back cover flipped out and joined to another back cover of a second Ewell case that would be used to house a USB character display. This was a picture of what I was planning when CT finally died, using Raspberry Pi in the back connected to the USB character display:
I went back in my steps remembering what I did wrong, when it all failed. I remember all the groping and pushing and that probably broke something inside. I consider myself a handy person, very careful when handling electronics, and I couldn't believe that I caused this mess.
Then with nothing else to loose, I started to push with my thumbs all the components, specially ram and flash memory. All in the opposite sense of Ewell case insertion, from the top of the board.
Yeah, that sounds stupid... I didn't even try to solder anything, just pressing the components and making an adjustement with my fingers... But after that, I tried again to flash Android, and YEAAHH! it went all the way... 100% completed!
Imagine my joy when CT booted and I saw that little monkey's face again! Seems something (I really don't know what) was out of place or who knows really... thing is that CT was alive again!
I've got my suspicions on the HDMI connector, my HDMI cable is thick and heavy and might also have helped to loose it, maybe just enough to cause this failure. But I don't wanna touch it anymore...
Unfortunately my other project was too far advanced, then it could'nt be undone anymore and CT actually became the third wheel... So what to do with this zombie ARM board? It just decided to finally work a little bit too late...
Actually I'm a proud owner of a Raspberry Pi board...
I have successfully mounted:
-A headless torrent server with Transmission and LCD2USB display board -Files downloader manager with PyLoad -A small NAS with USB portable disk, SMB y Debian (Raspbian) -A media center with Xmbc (Raspbmc), DVD player and 7" LCD monitor -A retro gaming console with PieMame and arcade joystick -A digital desktop clock with Clockatoo RTC Clock Board
I call it "RasPi-Rack"
I also own a Cubietruck and of course is more powerful! Still under development, looking to move some stuff here with Android and waiting for Ewell case to arrive... But in the meantime Raspberry Pi still is useful