A newbie exploring MCU's

[Dave]

Charlieplexing is a nice way to light lots of LEDs with just few uC pins, but it has one major setback: If one of your LEDs has a bad connection, several other will light up instead. It can be a real pain to figure out which LED is faulty, if something goes bad. 

[casper.bang]

Those tips-n-tricks docs are virtual goldmines. Although they go far beyond MCU's/PIC's, they should almost be a sticky in the dedicated micro-controller forum.

[casper.bang]

I feel I should wrap up my thread by describing my findings as a practicing MCU noob.

First of all, I did start with a PIC and a PicKit1 proto-board, but I never had much success with this. In all fairness, the PicKit1 is reasonably old (although USB based) and so had all kinds of trouble getting software to work, not made easier by the fact that I'm a Linux guy. A newbie with the PicKit2/3 on Windows might very well form a very different opinion.

Then I got a hold of the official Atmel avrisp mkii programmer with various ATtiny's and quickly wired up a programming board and installed the software with an apt-get onliner command. Within a few hours, I was writing C samples, compiling to hex, transferring to MCU and running the program on a breadboard. Amazing, as a software guy used to high-level abstractions and abundant hardware resources, to see the other end of the scale with an IC the size of a the head of a match, consuming just 7uA when sleeping.

So anyway, it may not apply to everyone, but for those used to standard open source tool-chains without a need of an IDE, I have to say the AVR experience with the tiny is very KISS and a hell of lot of fun. If/when I feel the need to move on to more advanced chips, the path seems paved and clear. 

[madires]

Just as a side note, I bought a Diamex ALL-AVR programmer for €31 because the buspirate is testing my patience :-) The ALL-AVR runs fine with avrdude (avrispmkII compatible) under Linux and is about 10 times faster than the buspirate. It supports ISP (3.3V or 5V), TPI (12V for reset too) and PDI. It also provides a 500kHz clock in case you messed up the clock fuse bits.

[ptricks]

The bus pirate is a great tool to have but I think in cramming in all the functions it became the ' jack of all trades, master of none'

[madires]

The bus pirate is a great tool to have but I think in cramming in all the functions it became the ' jack of all trades, master of none'

The V4 has more horsepower and an integrated USB. The USB speed of the old 3.x is limited to 115kbit/s by the FTDI chip. That also limits the programming speed. As soon as I see the V4 in a local store I'll get one and compare the programming speed with the V3.

[alm]

The bus pirate (v3) was not designed for fast data IO, but for interactive communication with relatively slow parts like sensors. I never considered the PIC/JTAG/AVR programming features anything but a clever hack, although I've used it once when I didn't have anything better available. For serious programming, I would definitely recommend a dedicated PIC/AVR/JTAG programmer.

[madires]

The bus pirate (v3) was not designed for fast data IO, but for interactive communication with relatively slow parts like sensors. I never considered the PIC/JTAG/AVR programming features anything but a clever hack, although I've used it once when I didn't have anything better available. For serious programming, I would definitely recommend a dedicated PIC/AVR/JTAG programmer.

That's exactly what I bought the ALL-AVR for :-) The puspirate is like ncat in the Unix world, it's a quite useful tool with tons of features. And it's supported by several software tool boxes (under Linux). So it's a good starting point, but if I dwell into a specific area I'll get the right tool.