Speed for COM 3

[JavaRN]

What is the speed for COM 4 (not 3 as in title) - is it 115k or 460K?

[roboard]

The maximum speed of RoBoard's COM ports is 115200bps.

Actually, RoBoard's CPU (Vortex86DX-A) has a feature to boost the COM speed. However, this is a experimental feature and very unstable in our test; moreover, it cannot produce an accurate buadrate to match Bioloid servos' buadrate. For the above reasons, we disable this boosting feature in the current RoBoard.


At 2010 Q1 or later depends on how we lucky, we plan to release an enhanced version of RoBoard, RB-100+. This version will employ the new x86 CPU (Vortex86DX-B) to solve the COM-port boosting issue. The maximum speed of COM ports will be 750Kbps, and its buadrate can match Bioloid servos at 500Kbps.

[JavaRN]

At 2010 Q1, we plan to release an enhanced version of RoBoard, RB-100+. This version will employ the new x86 CPU (Vortex86DX-B) to solve the COM-port boosting issue. The maximum speed of COM ports will be 750Kbps, and its buadrate can match Bioloid servos at 500Kbps.

It's a little too late! I already ordered the roboard, I hope I can manage to control my bioloid humanoid using a reduced baud rate!

[StuartL]

If you're in the UK then UK law allows you to return any distance purchase (i.e. something you weren't there in person for) within seven days for a full refund. This is to cater for these kinds of issues where you find out that it's not suitable for your purposes.

There are exceptions, for example holidays, where the act of purchasing or booking denies someone else the ability to purchase.

The roboard wouldn't be covered by this exception and if it's less than seven days old and it's unsuitable for your purchase you are entitled to return it for a full refund.

[roboard]

It's a little too late! I already ordered the roboard, I hope I can manage to control my bioloid humanoid using a reduced baud rate!

Some universities at Taiwan have successfully applyed RoBoard in biped walking control of bioloid humanoid.

Unless you want an advanced control or need to move numerous bioloid servos simultaneously, 115200bps should be enough for your purpose (considering the control rate for KONDO or HiTEC PWM servos is only 10ms~20ms).

May you try some experiments to see whether RoBoard meets your need?

[PedroR]

Indeed the preliminary information we got for the Roboard (that we were advertising) pointed towards 640kbps maximum speed.

This has clearly been reduced. I must say, however, that you can get a comm port on the roboard working at 1mbps or more using a prolific or ftdi chip connected to the onboard usb port.

It's a fairly inexpensive solution and you can get a small model like this http://robosavvy.com/store/product_info ... cts_id/392 to plug directly onto the onboard usb port.

Having said that, I must say Robobuilder - which is a Humanoid very similar to Bioloid in terms of the use of serial communication with the servos - works at 115kbps and it works very well. You are able to explore every feature nicelly.

From what I've read here
http://robosavvy.com/site/index.php?Ite ... m_openwiki I think the biggest impact this might have is when doing movements using S-Curves that may need frequent updating according to the document.

I think it will work well at 115kbps even because the load feedback feature for AX 12s is not really usable (and it's slow) and thus you won't be using the bus for too much feedback.
From what I understand it will be mostly for relaying commands in one way (Roboard -> servos) and there are packets to command multiple servos with one single instruction.
Feedback should be coming from an IMU connected to the SPI or I2C ports and from what I know those work fast

[PedroR]

I found an additional resource where the latency for the Bioloid bus is analysed.

It is here http://robosavvy.com/forum/viewtopic.php?t=990&start=45

I don't really know how to related these results to the 115kbps speed but nevertheless I wanted to post it here for your appreciation.