Jump to content
kvlasblom

Landtastic question

Recommended Posts

Hi, I have a question about the Landtastic project.

I have one spare channel on my R/C system which I want to use for the model's lighting on a three position switch. I would like to use the Landtastic unit to retract the landing lights, once the switch is in the furthest position. Can you program it to do that, so that it does not respond to the switch in the middle, but only in the last position (when the signal is at 100%)?

Step 4 in the setup sequence looks like it might configure that, but I fear that this configures the end position of the servo. Can anyone help me please? 

A second question is; can I use a standard servo or does it have to be a retract servo? I have a Hitec HS225BB servo.

 

Many thanks!

 

Share this post


Link to post
Share on other sites
Quote

Can you program it to do that, so that it does not respond to the switch in the middle, but only in the last position (when the signal is at 100%)?

During arming, the middle stick/switch region (1.5mS) is ignored. The thresholds are <1.3mS for low stick, >1.7 for high stick. But at all other times the servo position follows the stick position that is provided. So I doubt this will work for you.

 

Quote

can I use a standard servo or does it have to be a retract servo?

It is compatible with standard proportional servos, as noted in the project's feature summary.

 

Edited by Mr.RC-Cam
Clarification
  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the quick reply, Thomas! Sorry for the silly servo question. I'm impressed with your answer about the thresholds - how on earth did you know that?!

Anyway, this means that it will solve my problem, thank you! This is going to save me a channel. :)I will have to find one of those programming units for the PC first, sorry I don't remember what they're called; last time I used one was in the mid nineties!:o

I live in the Netherlands but I'm sure that Conrad in Germany will sell them.

Share this post


Link to post
Share on other sites

Hi Thomas, or anyone else able to help, I have made the circuit, programmed the chip and it is all working really nicely!

...except... I can't get it to ignore the switch in the first half of the full range. :(

So when I move my 3-position switch from 0 to 50%, the servo moves 50%. When I move the switch from 50% to 100%, the servo travels the rest of the way to 100%. I need the servo to move from 0% to 100% once the switch is in the third position, but to ignore the 0%-50% range. It would seem that the system is constantly responding to signal changes, regardless of the signal region, because if I put the unit on my elevator channel, even after running through the configuration sequence, it responds to all inputs.

Please help...

Share this post


Link to post
Share on other sites

Oh no! I overlooked what you had written before, "But at all other times the servo position follows the stick position that is provided. So I doubt this will work for you."

How could I be so dumb! I will have to think of an alternative solution......

Share this post


Link to post
Share on other sites

Sorry for the confusion. This is not the droid you are looking for.

If your R/C transmitter is running OpenTx firmware then you can create a mix that will do this for you.

Share this post


Link to post
Share on other sites

It looks like I'll have to purchase a new radio system. I was hoping to put it off a while longer; I'm still flying on 35MHz but bought the system (Graupner MX-16) just in the period when 2.4GHz was still new and wanted to stick with working and safe technology at the time.

Share this post


Link to post
Share on other sites

Hi author

I have built the servo controller as shown below.  When I tried to check my servo slower using this circuit, nothing happen when I rotate the pot in either direction.  But when I check the the same servo slower using mt commercially available servo tester it works just fine.  Is there any fix to this or do you have any recommendation of other servo tester that I can build that would work with your servo slower circuit.

 

Thanks for your time,

Ali

 

 

ServoController.gif

Share this post


Link to post
Share on other sites

Because of your circuit's simplicity I suspect its frame rate is out-of-spec. Landtastic expects the standard 20mS frame rate (50Hz) but will tolerate slower frame rates near 40mS (25Hz) found on very old R/C systems.

BTW, there are many cheap (<$5 USD) servo testers sold by eBay and China shops. Might be easier to use one of them.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×