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Posts Tagged ‘Raspberry Pi’

Mobile WiFi NAS on Raspberry Pi with TrueCrypt

Mobile NAS sounds like an idea worth waiting for to run on my mini Raspberry Pi Model A. Unfortunately, it only took me a while, before abandoning it. I’ve waited since writing about Raspberry Pi USB problem, that is to finally cut the backfeeding power line from the el cheapo powered USB hub. There comes [...]

Any m-by-n Matrix Keypad for Raspberry Pi

What about instantiating any m x n matrix keypad by a Python class? Raspberry Pi takes me to learn how to build a Python class for the first time while expanding my initial WiringPi-based matrix keypad into a derivative work. A matrix keypad instance is defined by: Actual GPIO pins used forming the row and [...]

Modem usb_modeswitch in Raspberry Pi

USB modem these days are plug-and-play as CD-ROM first allowing driver and internet dialer application installations and then as modem afterwards. This Windows-behavior is handled by USB_ModeSwitch in Linux. Likely three years ago we did eject and other driver attachment by writing udev rules. Now it’s almost automatically attached as modem after insertion and people [...]

Raspberry Pi Common USB Problems

USB problem is the first thing to arise with Raspberry Pi when plugging-in peripherals. This isn’t exclusive though, learning that my Linux laptop also has it and the higher ARM architecture, BeagleBoard-xM, also experiences the same issue sometime. But with Raspberry Pi (RPi) in

Raspberry Pi: Membrane (Matrix) Keypad as GPIO Input

Membrane matrix keypad using GPIO as Raspberry Pi input has been my goal since WiringPi deployed in the first place. To begin with, GPIO hacking was initially started with some important basics (see previous post). Without external system (other interfacing chip), the 3×4 membrane keypad reserved all seven GPIO pins plus one pin used for [...]

Raspberry Pi GPIO Input Button Basics

When you start hacking Raspberry Pi’s GPIO, first thing to keep in mind is the +3.3V CMOS logic level voltage despite the 5V supply. Secondly, read references about current limiting resistors (eLinux Wiki has a section there). What to avoid then? Try not to physically short the GPIO pin to ground when it is programmed [...]