Bricked MX-28

[xevel]

Hey guys,

I might have need for some help please ^^"

So, here what happened:

I have a couple of MX-28, had them for quite some time (at least relatively to the whole lifespan of the product). I had put them aside since I had other stuff going on, swearing I would get back to them soon.
Today, I took one, and with my freshly installed Roboplus 1.0.23.0, fired Dynamixel Wizard and successfully found my servo in the manager, using the default 57142baud setting. At this point, everything works nicely, the servo can be moved using the "target position" setting, the battery is 11.1v and full, cables are checked and all good.

Noticing the presence of an update (firmware 28 => 29), I ran the Dynamixel Update Firmware tool, clicked "next" enough time to get to the moment where it usually declares "success"... only to be greeted by a FAIL instead. During the process, the led of the servo lit up and stayed like that, even after the end of the wizard.
At this point, the servo is no longer recognized by Dynamixel Wizard. I closed it, opened it again, the servo is now silent and impossible to find even with a search on all possible preset baudrates.
I removed power from the servo, and when I plug it back, the LED does not light up for a second as it used to do. Still no way to communicate.

The obvious next move is to try to use the Dynamixel Firmware Recovery tool. The servo is detected as it should be, but when I select MX-28 and try to burn this firmware, I only get a "firmware update failed" or something similar.

TL;DR: bricked my MX-28 trying to update firmware, Firmware Recovery tool fails.

So... any idea, anyone?


PS: I might have to add that I am also a dumb f**k, since I tried the procedure on both my servos and bricked both, obviously... >_>

[PedroR]

Hi xevel

The MX-28 supports baud rates up to 3Mbps.

From our experience, if you set the Baud Rate to 3Mbps the current version of Dynamixel Wizard and Roboplus (that we use dback the at least) did NOT recognize the servos using a USb2Dynamixel.

With regards to reflashing the servo, I am quite sure the Bootloader should still be intact.

When loading new firmwares, the bootloader is NEVER overwritten (theoretically you can only rewrite the bootloader with an ISP).

For this reason - unless there was some electronic malfunction such as short - I sincerely believe the servos can still be recovered as the bootloader should still be alive.

I would recommend the following:

1) Download the latest version of Dynamixel Wizard and Roboplus (you can also try re flashing using Roboplus).

2) If you're using your USB2AX, try using a USb2Dynamixel instead. We discussed this before: it seems some Robotis software is specifically dependent on the FTDI chip (and the TriState buffers inside the USB2Dyn connected to the flow control lines) to operate properly.


I believe that, by default, upon reflashing the servos have their speed set to 1Mbps but newer firmwares may have changed this.

Again, the speed on the bootloader and the way it bootstraps the firmware upgrade should never be touched so the servos should definitely be recoverable.

Regards.
Pedro

[xevel]

Hello Pedro, Thanks for your reply

The MX-28 supports baud rates up to 3Mbps.

From our experience, if you set the Baud Rate to 3Mbps the current version of Dynamixel Wizard and Roboplus (that we use dback the at least) did NOT recognize the servos using a USb2Dynamixel.

Indeed. The USB2Dynamixel uses the FT232RL FTDI chip, which can not be used above 1Mbaud for RS-232. But unfortunatly, this is not the problem I have here.
It seems pretty obvious that the firmware does not run properly since the LED does not light up when power is applied to the servo.

With regards to reflashing the servo, I am quite sure the Bootloader should still be intact.

When loading new firmwares, the bootloader is NEVER overwritten (theoretically you can only rewrite the bootloader with an ISP).

This is also my understanding and experience. The bootloader must indeed be intact, since the Dynamixel Firmware Recovery tool can detect the servo. It just does not manage to install the new firmware.

2) If you're using your USB2AX, try using a USb2Dynamixel instead. We discussed this before: it seems some Robotis software is specifically dependent on the FTDI chip (and the TriState buffers inside the USB2Dyn connected to the flow control lines) to operate properly.

All of this happened using only the original USB2Dynamixel from Robotis.

I believe that, by default, upon reflashing the servos have their speed set to 1Mbps but newer firmwares may have changed this.

For the MX-28, it's 57200 baud (baud rate value of 34). I tried servo discovery using each of the preset baudrates supported by Dynamixel Wizard, to no avail.

It seems to me that the firmware that the wizard tries to install has a problem (corrupted upon download?), and so the servo simply does not boot up.


I saw that a new version of Roboplus is available (1.0.24.0, published yesterday), so I will try with this one (after cleaning up my computer from any older version of the application. My problem occurred with a fresh install of the previous version, 1.0.23.0

Download of Roboplus is mighty slow (2h+ for 150Mo... >_>) so I'll keep you posted.

[i-Bot]

Do we know that firmware install for MX28 from Dynamixel Manager works ?

From Robotis I only see described the process to update through Darwin Firmware Installer.

[xevel]

The option is sure available in the Dynamixel Wizard and Firmware Recovery software, at least.

I poked around with 1.0.24.0, and same problem. The bootloader can still be accessed with the Firmware Recovery tool, but it still ends with "Failed to install Dynamixel Firmware! Please Try again."

One strange thing however:
The size of the MX-28 firmware binary indicated in RoboPlus/Wizard/config/DynamixelFirmware.txt is 20096 bytes, and that's indeed the size of the file downloaded from the officil servers at http://www.robotis.com/Update/Dynamixel ... L_MX28.dxl
BUT when using the Firmware Recovery tool, the size indicated just above the progress bar is 20081 bytes.

Has anyone updated to firmware 29 on a MX-28?
EDIT: I mean using the Dynamixel Firmware Update tool. The firmware file used by the firmware_installer app on the DARwIn is not in the same file format, it's a regular .hex.

[PedroR]

Hi xevel

What I can say from our experience is the following:

We've updated the firmware on MX-28 servos successfully using the following setup:

1) Used Roboplus v 1.0.22.0 (this has now been replaced by a newer version)
I believe we've used Dynamixel Wizard (installed along with Roboplus) to do this.

2) Used a USB2Dynamixel and SMSP2Dynamixel to power the servo.

3) Flashed ONE servo at a time (ie only one servo connected during the firmware upgrade). I trust this was also your setup but I leave the info for others who may come here in the future for information.


I assume you have tried the "Dynamixel Firmware Recovery" option in the Dynamixel Wizard as well.


I would also recommend checking/trying with a different 3pin cable and also checking if the Power Supply to the servo is OK.

The 3pin cables (as you may have found out by yourself) sometimes develop some reliability issues over time and need to be replaced even though they often look ok.

Regards
Pedro.

[xevel]

Thank you for the answer Pedro

What you describe is extremely similar to what I did (only the software version and power source differ).
I also tried swapping cables with new, never used before ones, to no avail.

I guess my next move will be to try to use the firmware installer from the Darwin-OP software suite.
This will have to wait however, due to some upcoming holiday
Merry christmas guys

[xevel]

Hey guys!

I got back on this issue, and the solution revealed itself

Here is part of the changelog for the latest version of ROBOPLUS:

ROBOPLUS (robot exclusive software for ROBOTIS products) has been updated!
**Update Date : January 31st, 2012)
** Version: v1.0.26.0


> Wizard
- Firmware for MX-64 and MX-106 added.
- Firmware for MX-28 changed (P gain and D gain address switched)
- Restoration and update of MX series firmware
[...]

Tadaaa! It looks like it was just a bug after all.

And indeed, after updating to 1.0.26.0, I have had no problem salvaging the two bricked MX-28 with the Firmware Recovery Tool. Mystery solved.

Solution : update Roboplus to 1.0.26

Thanks a lot to all who helped