Control Feetech serial bus servos from UART or PC COM port.
How to add the Feetech Serial Bus Servo robot skill
- Load the most recent release of ARC (Get ARC).
- Press the Project tab from the top menu bar in ARC.
- Press Add Robot Skill from the button ribbon bar in ARC.
- Choose the Servo category tab.
- Press the Feetech Serial Bus Servo icon to add the robot skill to your project.
Don't have a robot yet?
Follow the Getting Started Guide to build a robot and use the Feetech Serial Bus Servo robot skill.
How to use the Feetech Serial Bus Servo robot skillControl 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!
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.
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).
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.
ARC has many parameters that can be assigned to servo movements. When selecting a servo, these parameters are specified by script commands or in the Advanced menu of robot skills. This skill supports the following ARC parameters...
- servo position
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 and additional hardware.
Load the latest version of ARC on your Windows based PC.
In ARC, press Project -> Robot Skills -> Add from the top menu
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.
Locate the Feetech Serial Bus skill on your project workspace. Press the Config button in the title bar to access the configuration menu.
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.
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.
Configure the Horizontal Servo skill by pressing the config button in the title bar
Selecting the port for this control. Press the Port button to select the servo port.
The dialog popup for port selection will display. Select V1 from the Virtual Port drop down list. Press SAVE
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.
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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Or you should be able to use an adapter like this for an ezb uart: https://www.robotshop.com/ca/en/sfe-uart-to-rs-485-converter.html
@DJ, The Rs-485 servos come with a factory default of 115,200 not 1000000, but easy to change in the software.
SM40BL Control Table_190901.zip
I have the RS-485 version and I am using the URT-1. See the above video.
I have also included the protocol of this servo in post #28
the protocol used is what they would have given us to have the robot skill created.
i might have a few minutes to look at the protocol doc you sent and see if it’s different. Who knows - hardware companies do strange things....