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Capacitive touch Drumkit with Raspberry Pi using MRP121

Couple of weeks ago I backed a new project Touch Board: Interactivity Everywhere on kickstater. This project excited me so much and I couldn’t wait for the finished product to arrive in March. I started to search for capacitive touch chips and finally landed on MPR121 breakout board on Sparkfun. Ordered them and received it 2 days ago and could not wait anymore and directly jumped into building a drums kit.

To make this work I did some research and everything was available but from different website. In this article I will put everything together in one place. I will go step by step

What do you need ?

1) Raspberry PI loaded with Raspbian OS.
2) MPR121 Capacitive Touch Sensor Breakout Board
3) Aluminium Foil for touch board
4) Connecting Wires

Configure I2C

I2C is a very commonly used standard designed to allow one chip to talk to another. So, since the Raspberry Pi can talk I2C we can connect it to a variety of I2C capable chips and modules. Please follow anyone of the following links to configure I2C on your Raspberry pi.

I2C and Raspbian wheezy
Adafruit’s Raspberry Pi Lesson 4. GPIO Setup

Connect the circuit

Can you detect the address of the MPR121 board ?

If you are not able to see 5a, try the command with i2cdetect -y 0. Still no luck! Google is your friend…

Download Code

Thanks to Scott Garner has contributed the complete source code of the beetbox. Download the code from github and run the program.

You should be able to hear the sound when you touch the foil inputs. If you are not able to hear the sound you can refer to this article to play sound file from command prompt in Raspberry Pi.

Thanks to Bare Conductive for inspiring this project… 😉

Fun With Raspberry Pi, Able-HD monitor as Media Center Using XBMC

Last week I received an email from Able-HD monitor team that my screen is shipped and it’s tracking number. They apologized for being late with the tracking code. When I tracked the shipment it had already arrived in my postbox and been waiting for a week. I went immediately and collected it before they sent it back for not collecting. After collecting I tested using Apple TV and it was gorgeous. The only comment I have to the Able-HD team is the connector is very small, if it was little longer it would have been better placing the driver circuit and the LED screen properly.

Later during the weekend I took my Raspberry Pi and decided to make it a home media center and to use the new screen. After many trials installing XBMC I was successful in running Raspbmc successfully in a decent speed.

I was able to play movies in airplay and it was playing okay.

Verdict: Raspberry Pi needs more memory to buffer 😉

Working with Raspberry Pi Camera Rev 1.3

Fastest online delivery I had ever experienced  was with Raspberry Pi Camera from RS Components. I received the package in 3days for a shipment fee of 8 USD.

The setup was very straight forward and simple, just follow the link. A sample shot taken using the camera, it has come out bad that is due to me not fixing the camera properly.

Raspberry-Pi-Camera-Shot

 

Going to attempt time lapse photography… will keep you posted 😉

Raspberry Pi with Redundant Power Supply

Everyday I get lot of ideas for Raspberry Pi. One such is to make it mobile like integrate it with my car. In that case I have to think of alternative power source if my car is not running. Lipo Rider Pro from SeeedStudio came to my rescue.LiPo Rider ProFeatures

  • Maximum 1A load output
  • Battery and Solar panel connector is JST 2.0
  • Stable 5V USB power supply regardless of source
  • Charge/Recharge algorithms built into chip
  • Charge Lithium Polymer Battery through solar power or USB
  • Stable supply voltage through either lithium battery or USB
  • 2 x USB ports let you program your kit while charging your Lithium battery
  • LED indications for battery full or charging states
  • 4 green LED instruct quantity of electricity of lithium battery

The above pictures shows that how I have implemented the Lipo Rider board for redundant power supply. I am not sure how efficient this will be on the move, so far I am happy that it is doing what it is supposed to do. Sometimes I get a feeling that the battery pack is always being used and it is not getting charged even if the USB power is connected. Have to debug this further 😉

Resize Raspberry Pi Partition Easily Using raspi-config

I have been playing with my Raspberry Pi for couple of weeks now and recently I ran into this issue of low space. Even though I had 8GB memory card it was only partitioned to use 4GB. After Googling for sometime I found there is a built in tool with Raspberry Pi which helps to resize the partition easily ie raspi-config.

Please check if your Raspberry Pi is running on Debian GNU/Linux wheezy/sid

Start raspi-config

Select expand_rootfs

Raspberry Pi raspi-config screen 1

raspi-config will configure Raspberry Pi to resize the partition during next reboot

Raspberry Pi raspi-config screen 2

raspi-config will request to reboot

Raspberry Pi raspi-config screen 3

During reboot process you can see that partition is getting resized

Raspberry Pi Resize Boot Screen

Once reboot is completed you can see more space on your rootfs.

Raspberry Pi Partion Info

I think this is the best way to resize the partition. No data loss or any special tool required to complete this operation 😀

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