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Posts: 1
Hi I somehow new to Mobiflight. I used to work with SimVim. since I wanted to have gauge compatible with both X-Plane and Microsoft I am testing Mobiflight.
Today I created my first gauge with Mobiflight with a stepper motor 28by 5V and ULN2003 Driver. Airspeed Gauge.
but I see some sluggish and jumps... The rotation of the needle is not smooth. In simvim it was just like a real gauge and the rotation is smooth. this is not the case in mobiflight.
Is there any solution for that? or its the penalty I should accept( Since the method of driving the motor is different. in Simvim there a dedicated Board for driving the steppers... Maybe that helps with the smooth driving...)

Any help will be appreciated

PS: I am using XPUIPC to connect to X-Plane. and the data is receiving in a acceptable rate as I see in mobiflight application. at least 3Hz.
2019-12-29 19:56
From: ETSI, Germany
Posts: 3322

Normaly Mobiflight work fine here..... Maby there is a technical issue in your systen but i think 95% this is a problem of the config settings by yourself.

Possible issues and solutions:

1. Change FSUIPC Poll rate .... In Settings Tab set it to a higher rate....
I not think this is the problem but if your Poll rate is verry slow then this can occure in jumping motors. Whatever your Config is correct.

2. Check your Config. ( Pretty sure THIS is the Problem)

A ) Is the MotorStep Count correct ? 1024, 2048 or 4096 ?
Find out by testing ..... Use SIM 1000 - Stepper 2048 - Test 1000 and press test button. If Motor turn exactly 360° you got a 2048 Stepper..... If it turn only 180° you got a 4096 Stepper....... If it turn two full circles you got a 1024 Stepper.

B ) Is the SIM Value big enough. It should be normaly a high number ( if possible nearly or bigger then number of Steps) . I Personaly use here 3600 in most situations.

C ) Does the Raw Value support enough single Numbers to give us a smooth output ?
If the Raw value just is a number 1-20 ( no decimals) then it have just 20 Steps..... So your motor mut "jump" between the steps. Thats logical.
If it have decimal Raw values then you must lnow the mobiflight logic here..... Mobiflight just export "FULL" Numbers to the Motors..... So a decimal Raw Value get shorted to the Full number by the system.
Means A Number like 1,001 and a Number like 1,999 are finaly for the motor both just "1" .
So if your gauge must show in 180° a increase of raw value from 0-20 then it will do only 20 jumps cause it not see the decimal increases between the numbers.
To solve THIS you must multiply the raw value (maby by 10,100 or 1000 ) so a numer like 1,001 and 1,999 change into 1001 and 1999 So you now got 1000 Signals instead of 1 before and your motor can do now 1000 smooth little increases instead of 1 ( aslong enough steps are available in that moving area of gauge)

Mostly point C is the problem. Check this out and report success or request for more help with detailed infos.
Good Luck !
2019-12-30 09:45
From: NW of KPWK, United States
Posts: 1441
Stepper rotation is supposed to run very smooth because the firmware has some logic to smoother travel between the set values.

Servos are sluggish but steppers should not.

Can you describe a little bit more in detail what sluggish means in your case?
Have a great day!

MobiFlight - Simply build your own home cockpit for your favorite flight sim - FSX, Prepar3D (FSUIPC), X-Plane (XPUIPC)
2019-12-31 17:50