Controlling 2 servo simultaneously with Phidget 8

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ech03
Posts: 3
Joined: Wed Jul 25, 2012 4:51 am

Controlling 2 servo simultaneously with Phidget 8

Post by ech03 »

I just started using Flowstone two days ago, and so far have been very impressed with it's ease of use and robot functionality. But I'm little confused on how to do the following.

I have 2 servo's connected to Phidget Advanced servo controller (channel 1 & 3). I'm using the right thumb stick to control one servo (on channel 1 in the X only for panning) and the left thumb stick to control the other servo (on channel 3 in the Y only for tilting).

Using the Phidget servo sample provided, this was fairly simple. But what I can't figure out is how to set it up so that both servo can be moving simulatenously from the different xbox stick inputs. They each work fine when I manually set them to one servo or the other.

I have searched the forum and samples online and found this post (viewtopic.php?f=2&t=406) but that doesn't seem to work for me. What am I missing about controlling multiple servos simulatenously????? Does anyone have a stripped down simple example for a noob?
DSP
Posts: 150
Joined: Fri May 14, 2010 10:55 pm

Re: Controlling 2 servo simultaneously with Phidget 8

Post by DSP »

The example I posted works for what you are asking:

Phidgets Servo Test4 RT.fsm
(10.73 KiB) Downloaded 1200 times


The Phidgets board can only process one thing at once but it can do this really fast so that it is transparent when using simultaneous inputs.

Here is an example using the Xbox controller:

Phidgets Servo Xbox.fsm
(613 Bytes) Downloaded 1204 times


In FlowStone when a number changes like a Float it also carries a trigger signal with it to tell things downstream that it has changed. It is these trigger signals that are being used to switch the channel in the servo module.
ech03
Posts: 3
Joined: Wed Jul 25, 2012 4:51 am

Re: Controlling 2 servo simultaneously with Phidget 8

Post by ech03 »

Thanks for the reply and files....

I'm still having an issue.....Here is the basic setup.....Xbox controller for manual control of 2 servos. Servo 1 is on Channel 01 (second input) of the phidget board and is being controlled along the X of right thumb stick (this is the panning servo). Servo 2 is on Channel 03 (fourth input) and is being controlled along the Y of the right thumb stick (this is the tilt servo).

If I have it setup in Flowstone with only 1 input linked (from xbox controller)to the "servo" module it works fine (for either pan or tilt servo). But when I have both inputs (left stick Y and right stick X) linked going to their repective seperate servo module inputs you provived.....either one is controlling both servos....so I try to pan and both the pan and the tilt servos move for instance.

I have attached a only slightly modified version of the Xbox file you provided. There is a little extra logic in mine to handle the xbox outputs (as I've noticed that their values even at rest fluctuate, so this is an attempt to create a threshold if you will).

I read in the documentation and forum that you don't need to use multiple phidget advanced servo primitives in flowstone, as flowstone can switch the inputs based on the included trigger in the floats.....but I'm wondering if it is possible to use multiple phidget advanced servo primitives for the same board in the same schematic. I because in my instance I am obvisously controlling multiple servos, and I want to assign different velocities, accel, min/max positions to each, and they are different servo models.....would just simply the development...at least for someone like myself who is just getting started.

Thanks and let me know your thoughts and results if you have a similar setup to test with.
ech03
Posts: 3
Joined: Wed Jul 25, 2012 4:51 am

Re: Controlling 2 servo simultaneously with Phidget 8

Post by ech03 »

hmmmmm I can't seem to upload my file to the previous reply.....can I email it to you?
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