Skill for serial Waveshare Servos

Question

Can you offer a RoboSkill for controlling serial Waveshare servos, e.g. type ST3215? Or are there already skills for serial servos that are compatible. E.g. Feetech serial servos

Athena · Answer

The Feetech Serial Bus Servo skill in ARC is designed specifically for controlling Feetech serial bus smart servos. If you are looking to control Waveshare servos, such as the ST3215, and there is no existing robot skill for them in ARC, you can create a custom robot skill to interface with these servos. To create a custom robot skill for your Waveshare servos, you can follow the guide provided by Synthiam on creating robot skills. The guide can be found here: https://synthiam.com/Support/Create-Robot-Skill/Overview This guide will walk you through the process of creating a new robot skill, including how to handle communication with the servos, parse responses, and send commands. You will need to have knowledge of the communication protocol used by the Waveshare servos to develop the skill. If the Waveshare servos use a similar communication protocol to the Feetech servos, you might be able to modify the existing Feetech Serial Bus Servo skill to work with the Waveshare servos. However, this would require a good understanding of both the Feetech and Waveshare protocols and potentially some trial and error. Remember, when creating or modifying a robot skill, you can use the ARC scripting languages (JavaScript or Python, EZ-Script, or Python) to send and receive data over serial connections, which will likely be necessary for controlling the Waveshare servos. If you are not comfortable creating a robot skill from scratch, you may want to reach out to the Synthiam community to see if someone has already created a skill for Waveshare servos or if they can offer assistance in creating one.

DJ Sures · Answer

If these servos are compatible with FeeTech, you can use any feetech robot skills.  here: https://synthiam.com/Support/Skills/Servo/Feetech-Serial-Bus-Servo?id=19570 and here: https://synthiam.com/Support/Skills/Servo/Feetech-RS485-Servo?id=20619 List of all servo skills here: https://synthiam.com/Support/Skills/Skills-Overview#Servo

DJ Sures · Answer

@Athena do you have any feedback on this?

Athena · Answer

If the Waveshare servos are compatible with the Feetech protocol, you can indeed use the Feetech Serial Bus Servo skills to control them. The two skills you've mentioned are designed for Feetech servos, but if the communication protocol is the same or similar, they may work with your Waveshare servos as well. Here are the links to the Feetech Serial Bus Servo skills for reference: 1. Feetech Serial Bus Servo: Feetech Serial Bus Servo Skill 2. Feetech RS485 Servo: Feetech RS485 Servo Skill Before attempting to use these skills with your Waveshare servos, it's important to verify the compatibility of the communication protocols. If the protocols are not compatible, you may need to create a custom robot skill or modify an existing one to communicate with the Waveshare servos correctly. For a full list of servo skills available in ARC, you can visit the Servo Skills Overview page: Servo Skills Overview If you need further assistance or have specific questions about the compatibility or creating a custom skill, the Synthiam community is a great resource to tap into for support and guidance.

robo-chess · Answer

Here is some additional information about the WS servos and the performance if this servos. Even if the Feetech skill doesn't fit 100%, they can be controlled quite well. Unfortunately, feedback signals for position, current and temperature are not running yet. Nevertheless, I have a good feeling for my choice so far and you have this hobby to develop things further.

robo-chess · Answer

Now that I finally own a Feetech servo, here is a short update on the topic of smart servo control with ARC. To make a long story short, I couldn't tell the difference between the two servo types. Both can be addressed in ARC, but I still couldn't get in any position feedback from either of them. For now, I can only hope that this will be taken into account in further skill development. Tabular presentation of my investigations:

DJ Sures · Answer

Thanks for creating that spreadsheet, but I'm having trouble understanding what it's presenting. Are there duplicate entries for the same product with different results? Even if I understood the data, I’m unsure how it helps with reading from the servos. The bus servos work fine for reading position and values - I’ve tested them successfully. The only drawback is that they can't release their position, making position readings useless. As for the other RS485 servos, I have no idea. The ones they sent me don’t even work with their own software, so I can't test them. shrug Your best bet is to contact them for answers or try speaking to someone directly from what ever company they are. They seem to be several companies? I do not understand the relationship between fintech and waveshape; just more Chinese nonsense. You could hire someone to develop robot skills for these, but without documentation or support, it’ll be a waste of time and money. If the company won’t cooperate with customer needs, there’s not much else to do. I looked into it, and I bill out at a few hundred per hour to our clients, so to give you an idea, I'm already several thousand into looking into this. Looking at the source code for the RS485 servo robot skill, I see there’s code for the reading position. I don't know what your chart indicates, but based on the code, it should work. If it doesn’t, the company needs to provide proper documentation.

Synthiam Support · Answer

I updated the feetech 485 skill to display debug data when reading. So maybe that'll bring some insight. The response from requesting a read position should provide a debug message in the log: "Give this to DJ." Because DJ can better understand it.

robo-chess · Answer

Today I received this response from WaveShare in response to my request for a WaveShare servo Skill in ARC.

This means, that the results of my tests (see table) have also been confirmed by WaveShare.

I will test the debug function later today and post the results.

It would be great if this could lead to progress.

robo-chess · Answer

Here is the feedback on debugging.

Test was carried out with 2 X Waveshare ST3215 and 1 X Feetech STS3215-12V.

All servos went into relay mode. No problem

Debug feedback:

V12 = Feetech STS3215-12V V4 = servo A WaveShare ST3215 V1 = servo B WaveShare ST3215

Is there anything else I can do? Please let me know. Anytime!

I hope it helps.

robo-chess · Answer

Hello ARC development team, thank you for the great update to the Feetech/WaveShare servo skill. It is now possible to achieve 100% servo control within ARC, and the power-on jerk is a thing of the past.

Great job!

I have developed a small test app that allows you to perform key servo operations and access (read/write) the servo's EEPROM. The app is public and stored in the cloud.

By the way, GPT-6 Astra created that little test app almost entirely on its own on my PC-not just the scripts, but also the selection of skills and the GUI layout. It’s a huge step forward that Astra can now work directly with the user's hardware and software, without needing any interfaces or plugins.

The only thing that could be improved further is the addition of a variable baud rate. That would allow other Feetech servos to be controlled as well.

DJ Sures · Answer

That's great to hear

About variable baud rate - you can't have multiple baud rates on a single uart. You'd need to install multiple robot skills (one for each separate port/ezb with a unique baud rate). Serial communication doesn't allow multiple speeds over the same wire because it'll garble the other receivers and be interpreted as something unintended. Plus, hardware switching baud rates takes time, and oh boy, there are a million reasons that can't be a thing with serial communication.

robo-chess · Answer

Perhaps "variable" wasn't the right word; what I meant was "adjustable." I understand the underlying concepts and am very familiar with serial data communication.

Currently, I handle it this way:

I have two Feetech skills running in parallel in my program. One skill is connected to the 1 MBaud servo controller, while the other initially writes to a virtual COM port. Then, outside of ARC, the baud rate is reduced to 115k, and the data is sent to a real COM port and the servo controller.

It runs stably, but it doesn't feel particularly clean. If the baud rate could be adjusted within the skill itself, that extra step wouldn't be necessary.

Of course, you would still need one skill per baud rate.

robo-chess · Answer

Sorry DJ, I just realized that it is already possible to set the baud rate. That wasn't the case before, was it? Great, then the Feetech servo skill is perfect!

Synthiam Support · Answer

That is wonderful to hear!

robo-chess

Skill For Serial Waveshare Servos

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