Dynamixel-AX-12A connected to Dynamixel Shield on Arduino Uno.
AX-12A is standard out of the box, no changes made to any parameter.
Official Library Installed.
12V 5A Power Supply.
Arduino is unable to find the AX-12A. I suspect the baud rate of AX-12A is too high for Arduino.
But i do not have a U2D2 to change parameters and check.
I would believe that you should be able to talk to the AX12 servos using the Dynamixel Shield and Arduino Uno, but I personally have not tried this.
That is because in the past I have used a few other AVR boards to talk to these servos. This includes the Arbotix board that was produced and used by Trossen Robotics on their robots.
I have also rigged up Arduino Mega boards for this as well.
And I have USB adapters such as the UsbToAX that was made by Xevel Labs.
All of these used 8 bit AVR based boards like the Uno.
So as suggested it might help to know what software you are using and maybe a picture of your setup.
Below is my custom baudrate scanning and change code for DYNAMIXEL AX and MX series. What only to do, is to define BAUDRATE in the line. --e.g, #define BAUDRATE 9600
Note: When I had tested this code today, I’ve found that the AX series with DYNAMIXEL Shield library has some comm issue on Some Baudrate (57600bps). The applicapable Baudrate in use of DynamixelShield library(v0.2.6) with DYNAMIXEL AX series is 9600, 115,200 and 1000000. If you are not using one of them, make sure to change it to one of the list.
DYNAMIXEL Shield has a UART Switch, which determines Upload Mode and DYNAMIXEL control mode. To do DYNAMIXEL, be sure to swtich it to Upload Mode. (The reason is to avoid TX/RX packet collision with hardware serial pins)