Here’s a new way to connect an Android phone and a Propeller microcontroller. It’s called the PropBridge and uses a very simple circuit with a voltage regulator, a couple of transistors, and a few resistors. The trick to this method lies in creative use of software features that already exist on Android hardware, the Android Debug Bridge (ADB). The ADB was added with development in mind, but since it provides low-level control of certain parts of these devices it was just waiting to be incorporated into a hack.
The Propeller itself uses firmware to make Android think it is one of two different externally connected hardware devices. It can act like a PC running the ADB client or it can mimic a TCP connection. There’s still plenty of room on the uC to add your own firmware, and the majority of the I/O pins are unneeded for the basic connection. Check out the video after the break for a quick overview of the system.
If you need a little help with Android programming before you’re able to use this in your own projects, check out our Android development series.
Continue reading “Propeller-Android communications using debug mode”
[REVENGE] pointed out a couple cool little project posts from the geekhack fourms converting vintage keyboards to USB with a Teensy. They both have VUSB support, so any avr micro controller that meets VUSB’s requirements in theory could be used.
First up is a PS/2 to USB keyboard converter, and while yes this has been done many times before, this one sports some extra features not often seen, like mouse keys, system and multimedia keys, and keymap customization. Instructions are also provided for use with a non USB enabled avr controller (like a mega 168, or 328) through the VUSB library (though with not all features available).
Next is pretty much the same thing, but it converts Apple Desktop Bus to USB, which is not exactly rare, but its lack of a clock serial signal, somewhat variable timing, and the fact that you wont find a bucket of Apple keyboards for a buck at the thrift store makes any ADB converter worth mentioning.
VUSB instructions seem to be the same for either, source is available and there are some cool pictures and info listed, and besides what is more fun than being able to plug your Model M into your netbook, or your Apple Extended Keyboard into your mac mini.
Many G1/ADP1 owners have been using the app Tetherbot to get internet access on their laptop via USB to the phone’s data connection. The app relied on the Android Debug Bridge to forward ports. It worked, but people wanted a solution better than a SOCKS proxy. The community figured out a way to create a properly NAT’d connection using iptables and then [moussam] rolled them up into easy to use applications. There’s one for setting up a PAN device on Bluetooth and another for adhoc WiFi networking. It requires you to have root on your phone, but hopefully you’ve achieved that and are already running the latest community firmware.