Category Archives: RaspberryPi

All about RaspberryPi

RaspberryPi the Arduino Development Tool

Not really too much to say here. There has been much talk on the forums about using arduino and similar systems to provide additional IO capabilities for the RaspberryPi.

So I decided to take things a little further and discover whats needed to use the RaspberryPi itself as a development platform using the Arduino IDE.

Following the simple steps below, it is possible to install, and run the arduino IDE, and then re program your USB connected arduino. Continue reading RaspberryPi the Arduino Development Tool

i2c connected 1-wire masters

OWFS the 1-Wire filesystem allows the use of i2c connected bus masters.

RaspberryPi conveniently provide i2c connectivity. However non of the images supplied provide i2c drivers. Fortunately at this point the community with its diverse range of members step in, within a few days an i2c driver is available. A few more days pass, more development takes place and the driver is now a loadable kernel module.

You can view the details of the driver development on this forum thread.

Along with OWFS working on RaspberryPi all the pieces are in place to begin testing of i2c 1-wire bus masters.

Pictured above is a breakout board containing 2 such bus masters, a DS2482-100 (8 pin chip) and DS2482-800 (16 pin chip)

Continue reading i2c connected 1-wire masters

The adventure begins.

So following the delivery of our first raspberry pi from RS, unboxed, and using the debian “squeeze” image it was time to see what works out of the box.

Here’s the obligatory output from /proc/cpuinfo

pi@raspberrypi:~$ cat /proc/cpuinfo
Processor : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS : 697.95
Features : swp half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xb76
CPU revision : 7

Hardware : BCM2708
Revision : 0002
Serial : 000000009a5d9c22

How about adding an FTDI serial adaptor

pi@raspberrypi:~$ lsusb
Bus 001 Device 005: ID 04f2:0402 Chicony Electronics Co., Ltd Genius LuxeMate i200 Keyboard
Bus 001 Device 004: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

So, how about 1-wire support.

Continue reading The adventure begins.

RaspberryPi 1-Wire Expansion

You can’t have failed to notice the buzz around the upcoming RaspberryPi.

Both it’s price £25 for Model B (with ethernet connectivity) and size make it ideally suited to home automation, of particular interest is the expansion header that makes several GPIO connections available.

Included on this header is an i2c connection, making it an ideal candidate as a 1-wire to ethernet convertor for OWFS.

I’ve begun work on two 1-wire breakout boards, both making use of the i2c to 1-wire master chips that are available, providing a single and eight channels using the DS2482-100 and DS2482-800 chip.

Board Features are as follows

  • RJ45 1-wire connection using the 1WRJ45 wiring standard.
  • GPIO Header for connection to RaspberryPi
  • 8 way GPIO Breakout header
  • 2 SPI breakout headers , one for each SPI enable line
  • Screw terminal for 5V power supply connection
  • i2c Level conversion from 3.3v to 5v
  • 3 pin DS18B20 connection (8 way board only)
  • 6 way 1-wire expansion header (8 way board only)

 

Screen shots of initial PCB layout below, PCB’s are 5cm x 5cm in size.