Last month I got Make: 24 with the very simple “Helium Balloon Imaging Satellite, by Jim Newell“ Jim used the PicAXE microcontroller and it really looked and sounded simple. What’s more? The PicAXE 08M chip he used was just $2.95 at SparkFun. To get started one may prefer http://www.sparkfun.com/products/8323 which is a starter kit ($14.95) with a chip, prototype board, cd, and battery holder for 3xAA batteries — soldering required. You’ll still need the programming cable: RS-232 serial ($5.95) or USB ($25.95). I went with the starter kit for $14.95 + the RS-232 serial programming cable for $5.95. Total outlay for initial setup: $20.90! Each additional project where I embed just a PicAXE 08M chip? $2.95! That is awesome. At this price point and size and weight a whole realm of applications opens up: telemetry for model rockets, embeddable controllers for wireless thermostats with on/off logging, and so on.
So the PicAXE looked simple in Jim Newell’s diy story. Is the PIC that simple? YES. I’ve programmed basic stamps in 1993 and I found the process straight forward. These seem about as easy and cost 1/10 the amount. What’s better? They’re not power hogs. I’ve programmed my 08M with this simple led flashing code (below) at it ran for about 12 hours on three NiMH rechargeable batteries before I uploaded a new program and worked on something new:
main:
high 1
pause 1000
low 1
pause 1000
goto main
PicAXE rocks so far!
(Yeah, there’s a LM35C on there too. It’s also measuring temperature. More later.)
A few technical details about the PicAXE 08M:
- 4MHz built in resonator
- 40- 200 lines of code memory
- 14 RAM one byte variables or 7 16 bit word variables
- 5 pins digital in/out
- 3 of which can be used as 10 bit ADCs (!!!)
- 4.5v – 5v power (I used 3x 1.2v NiMH AAs with a total of 3.6v and so far it’s worked just great)
Yes! The Picaxe is an awesome system! Been using it for years and it has much improved. Actually, now there are many more chips with much more power. A simple list includes speeds up to 64Mhz, Mtouch Technology, 4,000+ lines of code, multitasking, can run on as little as 1.8 VDC power, and much, much more! They keep adding and improving all the time. If you haven’t tried Picaxe yet, by all means do. Check it out!