With the recent release of the Raspberry Pi B+, I was lucky enough to be working right next to Westminster bridge where the very kind Element 14 were giving out free Raspberry Pi B+ and Ice Cream, both of which I managed to get my hands on, thanks guys!
One of the key factors that interested me with the new Pi was its move to more efficient switching regulators instead of the old linear (read: inefficient) ones it had before. This move, the Raspberry Pi Foundation tell us lowers the power consumption of the little board noticeably.
Being that I tend to run my Pis 24/7 (I now have a Pi Running OpenVPN, and a Pi running Seafile), the smallest difference with this relatively low power device should be significant.
Seafile had proved difficult on the B, as there are difficulties powering external HDDs from its restricted USB current output, the B+ promised to solve this, and I can tell you that it delivers! Read on for the numbers!
So this story beings quite recently, when, being the ‘noob’ that I am, I reversed the polarity while setting up the Linksprite UART camera ready for another post. Sadly, I had my bench supply set to unlimited current. Well, long story short, the camera is dead. Sad times, because beyond the first post I made about it, I haven’t even had a change to use it yet.
Well, having destroyed my latest toy, I thought I’d buy a new one to make up for it. No, really, I needed the tools to try and repair the camera, and well, I needed a Logic Analyser.
Pixel Commander is part of a much larger project I’m currently working on. Its purpose is to allow me to remotely control one of the LED boards shown in the image (the board design will also be open sourced when it is complete).
Pixel Commander takes commands over UART and uses them to change the state (colour, brightness) of the LEDs on the board.
Here is a small piece of code I threw together with help from the original source from Linksprite allowing me to interface with the Colour UART Camera from an Arduino board, over SoftwareSerial.
The reason I went for software serial is that this particular Arduino is to be used as a single node in a larger “internet-of-things” and the hardware serial port is required for communication over the XBee module that will be attached, to other nodes in the network.
Firstly, I’ll start with a diagram of the hardware. In this case I’m using a 3.3V Arduino Pro Mini. The voltage is critical, because the camera will need to run at 5V to be reliable. Fortunately, the Arduino is capable of regulating the voltage to it’s required level if it’s connected up right!
Dialogs are a necessary part of Android development, prompting the user for a Yes/No action is often required by applications of various types.
The Yes/No answer to these dialogs is usually of some importance, for example; “Are you sure you want to erase every single photograph you have ever taken?” and the Answer can often be “No”, because you clicked on something accidentally or because the UI design didn’t make it entirely clear what action you were about to perform, but that’s a story for another day.
Surface mount soldering if somewhat of an art. Maybe not a fine art, but one that I can appreciate none the less.