Interfacing a Basic ASI Gauge

[Boeing 747 Flyer]

Hiya David,

I ended up not getitng the HS-55, I spoke to a shop assistant and I told him the model name HS-55, and he gave me a different model but with very similar features.

Luckily, the one he gave me is much smaller than the HS-55, and easily fits within the ASI housing.

Next to master is the SIOC script. I will post a screenshot later today "labelling" what I think each section of the SIOC script means, then if I'm wrong could you steer me correct?

Thanks,

Jack

[fordgt40]

Jack

Ok, will try!

David

[Boeing 747 Flyer]

Hi Dave,

I've prepared this:



Am I correct?

Also, 737NUT mentioned a Pot for feedback... Is this needed?

[fordgt40]

Jack

One comment - I think that the Type command should be Type 2 for a 1024 bit servo (could be wrong, but do not have the docs to hand)
The POSL POSC and POSR figures represent the servo values for the start, centre and finish of your needle movment. You can get these directly from the test programme. Alternatively, you can put in the default values of 0, 512, 1024 (provided the servo can move freely to these positions without stalling). In this latter case you would need to alter the programming to reflect that the start of the needle range is position say 300 instead of 0. Either way you will need to programme the movement to reflect the different scales eg ASI needle moves x amount against a servo range of y movement.

Also cannot guarantee which way the servo may move in relation to the input values - sometimes you have to change the code to cater for this

Edit - you do not need a pot as the servo has one internally

Good luck

David

[737NUT]

A pot is only needed when using a DC motor and not a servo. Example, the VSI gauge i interfaced already had a DC motor and pot, i just wired them into a gutted servo and presto! A servo driven VSI guage that took less than hour to interface. Look for servo driven/electric only gauges.

[Boeing 747 Flyer]

Okay, and one final request...

Could anyone supply an example SIOC script for an ASI that I could modify for my needs?

Thanks alot,

Jack

[Boeing 747 Flyer]

Any ideas? Just an example ASi script that I could modify.

[fordgt40]

Jack

Perhaps there are none out there, so you will have to get your hands dirty. I suggest you just take a gauge example, perhaps 737nut`s ones above, change the offset reference to the air speed parameter you want in FSUIPC and adjust the coding to suit your specific needs.

David

[Boeing 747 Flyer]

Okay will do.

Just found out that the servo I purchased only moves 180 degrees. I take it this can still work if geared properly?

Var 0007, name ASI, Link USB_SERVOS, Output 1, PosL X, PosC X, PosR X, Type 2

^^^^^^^
Is the above script acceptable? Will I need to add anything? Also, Where I've put X... Does the number that goes here represent the minimum/maximum movements of the servo? If so, how will I find these?

[fordgt40]

Jack

Most servos only move 170-180 deg hence the need for gearing.

I answered your question about X earlier, you can find the start, middle and finish points by running the IOTEST programme that you have and taking note of the readings -though you need a completed gauge to do this.

Yes, you need much more coding, see 737nut`s examples above, as earlier suggested

David