Accessing the i2c bus on a Raspberry Pi using Ruby

I bought one of these :

201308311940.jpg

Which consist of 6 8*8 matrix displays. There are a few demo programs in various languages, but I want to drive it from Ruby, so a bit of setup is in place, including the necessary i2c drivers, as the daughter board sits on the i2c-bus.

Installing Ruby : https://coderwall.com/p/rmsi2w

i2c installation : https://coderwall.com/p/rmsi2w

pi@raspberrypi:~$ sudo i2cdetect -y 1

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: — — — — — — — — — — — — —

10: — — — — — — — — — — — — — — — —

20: — — — — — — — — — — — — — — — —

30: — — — — — — — — — — — — — — — —

40: — — — — — — — — — — — — — — — —

50: — — — — — — — — — — — — — — — —

60: — — — — — — — — — — — — — — — —

70: 70 71 72 — — — — —

So in other words it sits on i2c bus 1 – and the data addresses are 70, 71 and 72.

The to setting it up to see if it works from the command line :

pi@raspberrypi:~$ sudo i2cset -y 1 0x70 0x21pi@raspberrypi:~$ sudo i2cset -y 1 0x70 0x81pi@raspberrypi:~$ sudo i2cset -y 1 0x70 0xe0

The first turns on the oscillator – setting bit S in the “system setup” register – labelled D8 in the data sheet.

The next enables the display with no blinking – setting bit D in the “display setup register” – D8 again in the data sheet. To enable blinking then B1+B0 must be set to 01, 10 or 11 – i.e. replace 0×81 with 0×83, 0×85 or 0×87 respectively.

The last command sets the brightness level – in this case, leaving the brightness to the dimmest setting, P0, P1, P2, P3 are all zero in the “digital dimming data input”. Use a different value instead of 0 in the 0xe0 value – e.g. 0xef would be the brightest setting (all 1s).

And it Looks like something is displayed!
It looks like address block 70 is for 8*16 (the rightmost row of 2 displays. and 71 and 72 the next 2 rows.
The I download the driver from : https://github.com/meinside/raspi-adafruit-ruby.
The test runs – but only for one of the 8*8 displays. But it’s a good start.

HTML5 editing and creation tool – looks interesting

Hm! This may help out during rapid prototyping!

Tumult Hype, a powerful HTML5 content creation tool for OS X, was updated today to version 2.0. Designed to allow web developers and designers to create rich, animated web content without relying on plugins (like Flash) or other native code, Hype — launched in 2011 by former Apple engineers — has always been at the forefront of HTML5 editing software on the Mac thanks to a polished interface, powerful features, support for Apple’s iBooks Author, and compatibility with several web browsers and technologies.

[From Hype HTML5 Creation Tool Gets New Features, iOS Previews with 2.0 Update]