Feetech Serial Bus Servo

Control Feetech serial bus servos from UART or PC COM port.

+ How To Add This Control To Your Project (Click to Expand)
  1. Make sure you have the latest version of ARC installed.
  2. Select the Get button in this page to download the archive file.
  3. Double click the downloaded archive file to execute installer.
  4. The installer will add this control to ARC.
  5. Load ARC and press the Project -> Add Control button from the menu.
  6. Choose the Servo category tab.
  7. Press the Feetech Serial Bus Servo icon to add the control to your project.


Control Feetech serial bus servos over EZB UART or PC COM port. The selected ARC’s Vx virtual ports must match the servo IDs in the config scree  - and voila, you're off to the robot races!

Main Window
The main window on the project workspace will display information about active connection and errors. To configure the servos, press the ... configuration in the title bar.
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Configuration Screen
The configuration allows selecting the virtual servo ports that represent the ID's of the Freetech servos. For example, if the servo ID is #1, then V1 will be used. Also, the communication type must be specified (EZB UART or PC COM Port). 

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The baud rate of this skill is 1,000,000 bps, which is also the default baud rate for Feetech servos.

All new Feetech servos will have a factory default ID of #1, which is V1 in ARC. If you want to reprogram the servo ID, you need use the SCS15 software V1.6. from here. The software requires connecting the servo to either their USB device or using an Arduino. The Freetech website contains more information. 

Synthiam has plans to add an ID rename utility in the skill - however, we whipped this up in a few minutes for a quick test. Stay tuned for more features supporting Feetech servos.

How To Use
These steps will demonstrate how to add the Feetech serial bus skill to a project and use a standard servo skill control to move it. All skill controls that use servos will now be able to move the servo. This includes camera, joystick, scripting, and more. Simply select the virtual servo port and any skill will be able to move the servo.

In this example, we'll be using a USB Feetech servo controller. These controllers will create a COM port on the PC that we will select. The SCPC-2 or URT-1 work great for this application. Alternatively, if you wish to wire the servos directly to a custom hardware UART, it will require the option to be selected in the config menu in the steps below.

Step 1
Load the latest version of ARC on your Windows based PC.

Step 2
In ARC, press Project -> Robot Skills -> Add from the top menu
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Step 3
When the skills window is displayed, select Servos and locate the Feetech Serial Bus skill. Press the Download icon to download and install the skill to your project.
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Step 4
Locate the Feetech Serial Bus skill on your project workspace. Press the Config button in the title bar to access the configuration menu.
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Step 5
We will be using the USB COM Port to control the servos in this example. Select the Use COM Port option and select the COM port for the USB controller.

Additionally, the default ID of a new servo will be #1, which is V1 in ARC. A servo ID of #2 will be V2 in ARC, and so on. Select the V1 so ARC will now map all references of servo V1 to the Feetech servo with ID #1.

Press SAVE
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Step 6
Now we will add a basic servo control to test the Feetech servo. Press Project -> Robot Skills -> Add from the top menu. Locate the Servo tab and click the Horizontal Servo to add it to the workspace.
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Step 7
Configure the Horizontal Servo skill by pressing the config button in the title bar
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Step 8
Selecting the port for this control. Press the Port button to select the servo port.
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Step 9
The dialog popup for port selection will display. Select V1 from the Virtual Port drop down list. Press SAVE
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Step 10
The Min and Max range for the servo can be selected. Each control that uses servos will have its own custom range. Click in the Min and Max value and drag the mouse UP or DOWN to select the range. Or, alternatively you may right click to enter a range with the keyboard. Keep in mind, the servo will move into each range as you change the value. Press SAVE once the range has been adjusted to return to the workspace.
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You may now click on the servo value to drag the mouse Left or Right to move the position. If you right click, a numeric value can be entered by the keyboard. The servo will only move within the range you specify.

Try other robot skill controls, such as the Auto Position or Joystick with this servo. All robot skills that use servos can now reference this servo by the virtual port ID. 

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2 questions. Can this be used on the EZ-B using uart D5 D6? 

When might this be updated  be to include changing servo ID as described above?
1) it can use all ezb uart or pc com

2) I do not have a date for adding the utility to change ids. Right now we use the software provided by the servo manufacturer
Ok thank you for the info.
No prob:D 

They're utility software is really great and has a number of features that would be duplicate effort for us to implement. Makes sense to use the features implemented by their team.
Interesting.  The SCS15 SCS20 and SCS25 etc look size and bracket compatible with the HDD servo's. Maybe time to give my old JD robot an overhaul and cut down the wires (especially after the potentiometer hack). Anyone tested these servo's?  Do they fit in JD or other ez-robot brackets?   The Micro HDD is pretty small 10cm and I can't find a size compatible. SCS009 is 22cm so huge difference.  I guess I would need to keep the original HDD servo in the head, neck and hands (or do a redesign).
Why would you want to swap the hdd servos out? Nothing competes in that form factor
Position Feedback, Higher Torque (25kg, 30kg, 35kg), Less Wires ...  If you spent some time redesigning the servo brackets / connectors you could also remove wiring all together.  I love the Clicbots, they use TTL servo's  and no wires.
That clickbot was one of the worst experiences I’ve had with a product. There’s not enough power because the servos connect inline with high resistance of each connection. 

I misunderstood your original post about switching the hdd servos because you mentioned potentiometer hack. But I think what you were trying to say is swapping the servos doesn’t mean you have to do the hack. 

I haven’t had great experience with these servos coming close to the advertised specs. But they should be ok - maybe not great for a jd but I’d like you to find out:) worth the trial!