E-Wheelie: Homebrew

[hk-willem]

Hi All,

I have also decided to build from scratch.
I have a interesting question.
If I want to use a TQFP Atmel ATMega32 will the Hex files worked as is or will it be needed to re-compile for the new physical footprint?

Willem

[guenter]

Hello Willem,

the TQFP is no Problem. My Wheelie has an TQFP:

http://www.gerold-online.de/cms/en/wheelie/mein-wheelie.html

[thomas scherer]

@HK-Willem
Have a look on this screenshot made from AVR-Studio 4

[edjacob]

Hello, I´m starting to build this stuff but I could´t find the original sensors, IDG300 and ADXL 320, so I got a finished board with IDG500 and ADXL335, from sparfun.
Do you think that I have to tweak the software to have a good performance with these sensors ?

Thanks

[thomas scherer]

IDG500 should be totally equal if you set it to "500°/s full scale range (higher speed)"

For using the ADXL335 instead of ADXL320 you should better match the gain difference in the firmware for the 335 delivers 300mV/g vs. the 320 with its 175mV/g. With other words: your replacement is more sensitiv.

Maybe it would be easy to have a look in the newest open firmware in the german forum because this code is simpler to read an modify: http://www.elektor.de/forum/foren-ubersicht/foren-zu-elektor-projekten/elektorwheelie/elektor-wheelie-open-firmware.1131470.lynkx?pageStart=11

But see the latest versions attached here for your conveniance:

[bobbygee]

Well I'm back after an extended period of unemployment (therefore limited cash) and dubious health. I am currently debugging my PCB designs and particularly the sensor area as I am very new to surface mount and I find I am battling that at the moment. I have attached some pictures of the PCboards I have made. Hope to move on to mechanical assembly shortly.

[guenter]

Super PCB!!

How did you make the vias?

Günter

[bobbygee]

Hi Gunter,
I use 'Express PCB' software to design my boards and then submit them by email to be manufactured ... presto in 5 working days these beautifully manufactured PCB's arrive from the USA.
http://www.expresspcb.com
These boards are all 2 layer (although it is possible to do 4 layer boards) and all component holes are vias (I overlay a via hole onto smd pads). I use a groundplane on the top as ground and another one (sometimes more than one) on the bottom for + supplies.
The boards I use are a special Miniboard' prototyping service and are manufactured in quantities of 3 (2.5"x3.8") boards for around US$51.00 plus postage.
I have used this service for years and find that even my dodgiest prototypes look and perform great.

Regards Bob'

[bobbygee]

Finally got my prototype set up in a test jig, now have to source another battery as one of these is faulty.

[thanx]

All of the PCB components with the exception of the IDG-300 are available from Farnell Electronics. The IDG-300 is available from the manufacturer, Invensense, directly.