The GnuVision Blog

Did this before the Vellore journey - Read more…

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PyNeko has been extended a little bit - now, we can build walls between cells.

Check out this link

I have introduced the first Python keyword, `def’ in chapter 5 (neko learns some new tricks). Now, it is time to introduce variables and iteration. The variables-as-name-tags approach (rather than values-in-boxes) seems to be better, as […]

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I needed to get a serial bootloader onto an Atmega16. Here is how I went about doing it.
First, install `avrdude’ - it’s a much more capable program than `uisp’. We need it because `avrdude’ supports a lot of methods to burn code - including communicating with a bootloader based on the Atmel Appnote AVR109 […]

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Many modern microcontrollers have on-chip debug modules which can be accessed via JTAG - these debug modules let you do stuff like stop a program in execution, examine registers/memory, single-step through the code etc.
It seems the working of the Atmega16 on-chip debug module is not completely documented - but Atmel has done one […]

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It was Insignia day 2 today - and it was time for the hack-the-badge contest! I reached the CS department by 2:30 and
saw that there were only a few participants. I began by describing how the badge PCB was built using GNU/Linux tools. This was followed by a very brief introduction to the Attiny […]

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Finished writing the code for the badge; nothing fancy - just 4 red LED’s and a switch. The muC goes to power down mode after executing some initialization routines - the current consumption is less than 1uA in this mode. The switch connected to PB4, when pressed, will result in a pin change […]

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Started building my poor imitation of the Defcon badge today; I am using uisp with the simple direct parallel port access circuit.

I am going with the 8 pin ATTiny15L - don’t want to spend time soldering smd stuff. A 3V button cell is the power source. The tiny15 is much more capable than the […]

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Very low cost microcontrollers are extending the use of software to many unconventional applications:
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Here is a photo of two `tiny’ microcontrollers I had purchased recently; the bigger one is the ATTiny15 in an 8 pin DIP package and the smaller one is the PIC10F206 in an SOT package. The PIC costs only Rs.25 […]

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I have been busy with classes for the past few days. I am also learning to do a bit of PCB design with GEDA - GNU EDA Tools. Doing schematic capture with Gscheme and PCB design with
PCB is not that hard - but there is an acute lack of documentation in this area.
I […]

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Operating Systems design is very much a `hands-on’ course; there is no point in learning lots of text-book theory unless you get your hands dirty with code. What kind of code do you ask your students to play with? The Linux kernel is one option - but I feel it is too complex as […]

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