TI Launchpad

Recently I've been trying to do battery powered devices and I came to the conclusion that there is more to it than you first think.
My experience with the Bird-O-Matic is that it each battery lasted only 25% of what I had planed. There were some options that might have influenced it:

• I didn't made an OFF timer, once the PIR detects an warm object it turns ON the MP3 player and the Amplifier for some time (7-10 seconds), placing a forced OFF timer of 20-30 seconds would prevent constant re-triggering every time someone passes by.
• Was the use of a CMOS 555 better than a micro-controller? Today's controllers consume almost nothing in standby or power down mode, and a wake up on pin changed could be used with the PIR.
• The external MP3 player consumes a lot of power and takes 1-2 seconds to start up. It was the simpler and fastest solution, but not the best for power saving.

Recently I read about the MSP430 ultra low power capabilities and I wanted to try them out. The Texas Instruments Lauchpad let's you do just that at a very low price (about 10EUR) and a big Windows installation (see here). I admit I'm always very reluctant to install windows software but unfortunately these links for installing in Linux didn't work out.


It is a bit sad, but I'm no sysadmin and no I don't know perl and I don't want to lose time learning perl, to correct a script, to install a msp430-gcc, to program devices... I understand the technical difficulties behind maintaining and supplying a gcc distribution (specially if also sell a payed tool), but nowadays it is becoming a "must". Sounds like when AMD started giving away PALASM... suddenly every PLD manufacturer started doing it or... went out of business..
After installing the correct tool (the free version is not the latest version), I followed the start up guide and sure enough I made my first C program.
The tool is simple and powerful (based on eclipse), in Windows everything works mostly out of the box.


The board is "divided" into a emulation tool and the experimenter board where devices of 14 and 16pins can be connected. There's also the option of soldering (an included) SMD low-power crystal oscillator. Instructions are also provided on how to measure the power of the experimenter processor, although it is tempting do not cut the board through the dashed lines.. it will not work as a MSP-ISP... that's another tool. (but I guess removing the jumpers and direct connection is ok :-).
The processor although a 16bit simple RISC architecture does appear to be quite capable, I just tried out a couple of examples in C. This though is not what I want to try out... I want to see if the operating current is as low as "advertised", but that will have to be for a another post.

Christmas Ball (the 11.11.11 post)

It is a bit late to announce but we won a prize!!!


Huyser bookstore in Delft ran a competition to promote the book from Arne and Carlos "55 Christmas Balls to Knit", see the promotional video here. Just before the deadline (1.11.11) our son Daniel was born, but we managed to find time to finish the Ball and submit it.
Naturally Ana chose a pattern and knitted the ball, I took care of the electronics. We were so late entering the competition that we only have "night shots" before submitting the ball...


It is a simple ATTiny15L powered with 3x AAA alkaline batteries.
There are 4 LEDs connected to the ATTiny, each in one of the reindeer's nose.
I've made a 32bit pseudo random number generator with a LFSR. The ball to lit is randomly picked (1..4) and also the fade-in time (1-2sec), fade-out time (1-2 sec) and off-time (2..4 x 2.5sec i.e. number of watchdog cycles).
The average measured power consumption is 1.5mA so one can expect about 1000 hours of operation from 3 standard cells.
(click on the circuit for a better view)


The schematic is not exactly this one, this is for another project that hopefully will come out before Christmas, just remove the solar charger, the voltage measuring and that's it!
We got the third prize, 100EUR in books!!!