Recently I had the need to produce time-lapse videos for very long periods of time. That is not a big deal when you can use a nearby power source, but I would like to have an autonomous time-lapse camera that can run several hours. So I decided to build it with my Raspberry Pi.
Recently (actually almost one month ago :), I had to power several devices (three different units) using one of those battery packs with an USB output (http://papermint-designs.com/community/node/289). The easiest way to do that is to power a USB hub with your battery pack and then use the hub to provide power to all other devices. That will work OK as far as the current needed by your devices fits the output of the USB hub (around 100 mA).
Some weeks ago I had to show a set of images in something you can "wear" and that sounded as a good opportunity to play a bit with my Raspberry Pi. The first solution (out of three :) I come out with was to convert the images into a big PDF file (thanks ImageMagick) and then use xpdf cool "-remote" flag to navigate the pictures. Do not know about -remote?... Type "
This is a picoFlamingo minor intermediate release (the second release candidate). Source code is available from the project website:
This release includes some clean up but the main addition is preliminary support for Raspberry Pi, and preliminary means some imitations.
Recently I acquired a couple of HDMI 2 VGA converters. I'm interested on interfacing my small boards to VGA devices and, as many of us already know, finding a working one is a trial and error process. So here are my results and I hope may be useful for somebody else.
I've got two different models (powered and unpowered) and tested them with my HDMI enabled boards (BeagleBoard, PandaBoard and Raspberry Pi). These are the links to the devices in case you are interested.
It took more than 5 month to get our Raspberry pi. It finally arrived this morning. Most of the enthusiasm was gone weeks ago, but anyhow we had to check the board. The initial plan is to port picoFlamingo (http://papermint-designs.com/picoflamingo) to work on the Rpi, but I do not think that anything will happen before Xmas break. Some stuff for PandaBoard needs to be finished first.
Anyhow, a couple of mandatory pictures for new devices.
Probably you already know that the Pandaboard provides two extra USB ports through connector J6 (pin 1 to 8). You probably also know about the nice article in the elinux wiki on how to easily use those (http://elinux.org/Panda_How_to_add_2_USBs) extra ports. I found that article after soldering a female header on my Pandaboard expansion ports.
After playing for a while with the Beagleboard (http://beagleboard.org) Expansion Header now is time to explore the PandaBoard one (http://pandaboard.org). I soldered a couple header sometime ago and finally I found half an hour to play with them.
Some time ago (actually around three weeks more or less) I expressed my interest on the Raspberry Pi and a couple of days ago I'd got an invitation to order, so the small board will arrive, hopefully, within the next 12 weeks... That's really a lot.
No special interest on the Raspberry beyond the low price profile for a modest/small GNU/Linux computer. I mean, there is nothing I cannot do with my BeagleBoard or PandaBoard that I could do with this raspberry but deploying them as Arduinos.
Now that we can power our BeagleBoard through the expansion header (http://papermint-designs.com/community/node/223), it is time to go a step forward and power picoFlamingo on batteries. Using the expansion header we can easily include the batteries inside the case to power the system and keep it pretty small. But, what is still missing, is a way to make the system aware of the battery charge.
Anyone that had tried to produce a kindof closed thingy based on a Beagle has finished up with a bigger-than-expected box or with quite some connectors sticking out the box. The power jack is a difficult one because you always need power.
It is not that much of a problem as you need to connect your board to some kind of power source anyhow, however, for a "better finished" product you will expect things like a power switch and some LED indicator in your project's box (the POWER_ON led on the BeagleBoard is not very useful when you put the whole thing inside a box). Even worst, if your system will run on batteries it is not very aesthetic to see a big barrel connector going out your box into the Beagle power plug.
Our previous interface to ID-12 was pretty cheap. Around 2 Euros for a Logical level converter and some wires, but as the ID-12 RFID reader does not need any programming or command in order to work, we end up just using the RX line from one of the available channels in our converter. That looks like a waste :).
Recently we've been exploring the Beagleboard Expansion Header on our old BeagleBoard C3 board running Ubuntu 11.10. We installed Ubuntu following the instructions on http://elinux.org/BeagleBoardUbuntu#Oneiric_11.10. Then we explored the GPIO pins in the header (http://papermint-designs.com/community/node/205) finding out how to use them as inputs and outputs and later we tried the I2C bus (http://papermint-designs.com/community/node/210) using just a couple of components for those of us that do not want to invest a lot of money on simple tests.
After playing with the GPIO (http://papermint-designs.com/community/node/205) for a while, let's move on through the BeagleBoard Expansion Header. Now it is time for the I2C bus. I2C bus is available through pins 23 (Data) and 24 (Clock).
Finally I've been brave enough to solder a connector into my BeagleBoard expansion header to further explore how to attach different stuff to this little one. After verifying that the board still boots (i.e. it survived my poor soldering skills :) I went for the "Hello World" for this kind of hardware... a blinking LED.