Airspeed indicator interfaced with OC cards

[edo17982]

Hello guys I post here a link to my youtube channel where I'm posting videos of gauges conversion as i complete them.
Any comment / question / suggestion will be appreciated.
Hope you'll enjoy!!

http://www.youtube.com/user/Edoradar


Edoardo

[fordgt40]

Edoardo

Excellent work and very impressive, especially with DC motors rather than servos

Well done

David

[737NUT]

Edoardo

Excellent work and very impressive, especially with DC motors rather than servos

Well done

David

He is using a dc motor with a feedback pot, same as a servo. None the less, nice job

[Anderson/SBSP]

Bravissimo!!!

[edo17982]

He is using a dc motor with a feedback pot, same as a servo. None the less, nice job

Yup you're right, the good is that I was able to use the existing DC motors inside replacing resolvers with pots with some mod to the housing.
The bad is that OC don't use a PIC with higher resolution a/d and that is a limitation to smoothness and a big limit in those devices that have lot of turns like altimeter... any idea on how to pass over that?

[737NUT]

Use a multi-turn pot and gearing, one turn = 5K or 10K feet just a thought

[edo17982]

Already thought abput that but the result wth 256 steps only (8 bits) is that on, let's say, 60K feet range each step would be 60000/256 = 234 ft which is not possible... a thought was to use 2 pots...one rotate each 2000 ft and one make a rotation within the full range which work as a sort of counter...I need to elaborate a sioc script for that but could be a solution. the only bad is that a continuous rotation pot has a dead angle of more or less 20°....

[737NUT]

Well most planes dont fly above 40K feet so that could help on the resolution. Also the servo is 10bit so that may help also.

[edo17982]

Yup you're right.. i'll post it once I'll find the most suitable solution

[fordgt40]

He is using a dc motor with a feedback pot, same as a servo. None the less, nice job

From his Youtube text it was not apparent that he had actually cannabalised existing servos. Also, as you are aware the programming of "raw" dc motors with separate feedback is much more complicated in SIOC than using servos - hence my comment

David