AX-12 circuit diagram?

[bootstrap]

That's fantastic, thank you! I presume, from the degree of documentation, that you're reasonably confident in it?

Hi ,I was able to build an Atmega128 board and was able to talk to the AX-12 .I transmitted the packet from the PC to Atmega128 via the USB-232 Converter and via MAX232 at 115200 Baud. Then echoed the same packet to AX-12 via the UART 1 but at a baud rate of 1Mbps.

(Also I thank Jon and Dave Hylands for their extensive support )

Also there is a dynamixel commander software provided by forest moon
http://forestmoon.com/Software/DynaCommander/

Individually both the servos were working fine.But later when I daisy chained them and tried to change the parameters the AX-12 closest to the servo stopped responding.Both the servos stopped responding now.Although the LED flashes when powered up.

What shall I do please suggest?Are the AX-12s now dead?I have an STK200 dongle ,shall I wire it up to the atmega8 and reload the firmware.

By the way are you using Zigbee to wirelesss upload the bootloader?

[Zoid]

Update? Has this topic moved to another thread?

I'll be hacking my CM-5 for ISP downloads soon (so I can ditch BCP), and shortly after that I *may* want to reprogram my servos. Depends on how much progress has been made to the firmware.

[StuartL]

We do have working AX-12 firmware (with bugs) but have not yet decided whether it's worthy of release.

Almost all of the code (probably 99%) is scratch written by RandomMatt and as such any release decision is entirely his.

We have just this week, though, discussed the possibility of a new servo operating mode that may be able to hit 100-500Hz update rates across the bus. To achieve this all bus devices would have to be aware of a new protocol, we haven't yet ratified whether it could be backwards compatible.

Obviously the CM-5 cannot keep up with these update rates so we're assuming that the CM-5 board is replaced for such a project but in principle Matt is confident (and therefore I am confident) that it's achievable.

[Fritzoid]

The firmware seems to be using PB0 for something motor related too. The circuit diagram shown this pin as unconnected. Any comments ?

[Fritzoid]

PORTD5 is set when Torque Enable is set to 1 in the control table. This must enable the motor circuitry.

PORTB0 seems to control the actual motor. Setting this bit on will start the motor and resetting the bit stops it.

I'm pretty sure that these pins must connect to the H-bridge circuitry somewhere.

[i-Bot]

I will take another look at the AX12 PCB, but we were pretty sure those pins were not connected.

It may be Robotis use the same code for the RX servos which use the L6203 driver and do need an enable signal. Or they may just have some signals for debug.

I did notice some large shoot through current pulses on the Ax12 servo power supplies, maybe they should have an enable !

[MOHIT JINDAL]

I wake up 4 year old post. There is only one 74HC126D on Ax12+. Is it the motor driver ?
How much current it gives to tiny motor inside ax12
Why the J2 is empty with 5 holes

[wiweet]

No Mohit, 74HC126D is quad buffer IC used for communicating between the AX and the Controller(CM-5 or CM-510) on the Dynamixel Bus.

For motor driver AX-12 use SUF2001.

For detailed datsheet of those IC you could go to www.datasheetcatalog.com

And the 5 empty hole is used at Robotis Factory to flash/programming the ATmega8 inside the AX-12.

[MOHIT JINDAL]

Is there any code programming inside 74HC126D... buffer IC ?
How much current SUF2001 give to tiny motor ?
Can i get/read the atmega 8a code from J2 5 holes from ISP ?
I searched and found that SUF2001 can give 5amp current. Now I think a resistor is soldered on Ax12+ chip to block current and make it 1.2amp.
Datasheets are very confusing Many ratings of current and volt

[MOHIT JINDAL]

I checked the current from dmm. SUF2001 give only 0.07amp to tiny motor. I think a resister is soldered in between to low current. Is there any way to increase current ? please also answer my 3 questions above.

[MOHIT JINDAL]

Recently I noticed the firmware of AX12+.
I opened ROBOTIS folder and go to C:\Program Files (x86)\ROBOTIS\RoboPlus\Wizard\config
There is a file DynamixelFirmware.txt which has the links of all Servo Firmware. The firmware is .dxl file. I thought its .hex or .bin
Then I checked how to read .dxl files.
We need "IBM Rational DOORS" to read .dxl executable files.
I made IBM ID and loginned to access Rational DOORS Trial version Web Access. But its not opening after I pressed continue button. Maybe some country restrictions.

[Fritzoid]

Even though the file extensions (.dxl) are the same, I seriously doubt that the files used by the Dynamixel Wizard are in any way similar to those used by IBM.

A Robotis .dxl file is probably some type of compressed .bin file.

[limor]

i recall we had loads of discussions about the format of the AX12 firmware. can't find the thread now (maybe links here). Eventually it was figured out that you can get the bootloader prompt from the AX12 just like you get it from CM5 by linking usb2dynamixel to a single servo, setting COM at 1mbps and using a terminal emulation and pressing # key during power-on. the format of the file is the output of the AVR gcc compiler. if you look at http://actuatedcharacter.com we have a fully working alternative firmware and instructions for flashing (and there's StuartL's firmware found on other threads here).
So i don't know what is the dxl file but if it is a firmware for AX12 then it must be the same format.

[MOHIT JINDAL]

I finally taken out one circuit to break. i taken out atmega 8a, marata potentiometer, SUF2001 and 74HC126D. the circuit schematic given from i-bot and Chris.H misses the pin 7 and 14 of 74HD126D. I saw from magnifying glass of 65mm. Pin 7 is connected to T1 and pin 14 to U3. Am i correct ?

[MOHIT JINDAL]

Hi, Its me again. I think nobody is interested in this old topic. But i checked the motor.pdf again, there is no PWM line going. Why ?