I am trying to avoid connecting the USB adapter - the size of it wrecks my application and the price of it makes it unviable!
The reason why the servo is not responding is, I think you probably have not wired the AX correctly! As for the crazy baud rate, ask those Korean dudes mate!
Check the power line (I made this mistake once myself when I first got it), GND is pin 1 and VDD is pin 2. If you read the manual hastily (I did this) you might have seen the diagram which says pin 2 is “Not connected” - and unfortunately if you connect GND on pin 1 and VDD on pin 3 the AX LED will “blink” to say it is on, but it does not respond to commands - all rather confusing really! The diagram which says pin 2 is “Not connected” refers to the connection from (CM-5 or USB2Dynamixel) controller to the servo!
Of course what I am trying to do is bypass the use of CM5/USB2Dynamixel and control the servo directly from FEZ (mini) - that keeps my app lean and mean. B)
When AX12 is powered on, the LED will come on for a second and then it shuts back off. Is this normal? I am trying the ping command for now. Haven’t tried anything else yet
Also you may want to try the “LED On” command instead, as you will get visual feedback even if you are not receiving the status packet. Also bear in mind that the AX-12 manual states it will operate at baud rates 7343bps ~ 1 Mbps. I am told that software implemented UART only works up to baud rates of about 115200bps. I don’t know how correct this is, but it is well within range for my purposes.
I haven’t been programming the AX-12 for long, so I cannot help you much else on the technical side I’m afraid!
Other implementations you saw only works with 115200 because that is the maximum baud rate usually supported on a device! FEZ can do 1MB very well.
I had ordered another servo and ordered the USB controller. I wanted to experiment with it first, to understand it, before I try with FEZ again, since I did write the code but somehow the servo is not responding!
http://www.crustcrawler.com is the worst website I have ever dealt with!! After placing an over-night order and paid too much for shipping, I received nothing after 2 days!! I call the company, and of course it is a one man business and the business phone is actually this guys cell phone, he told me it will ship on Tuesday. I didn’t feel like arguing with him…
…then nothing on Tuesday and nothing on Wednesday. So I call again and no one answered the phone so I leave an angry voice mail…
…so finally I get some call back telling me it is shipped on Thursday so I should have it today…nothing so far but it is still early morning…
You should get him to become a FEZ distributor and then he will make enough money to become a 200-man corporation because FEZ is sooooooo goooood!
Don’t worry about the long story - I know your pain! Mind you I thought you reckoned RobotShop.com was the best place in the states? I must say I am surprised about crustcrawler.com because they (he?) has some good info by way of help files etc. on their site. Oh well, on the web everyone is anonymous… hope you get it soon! Have a good weekend! (Mine’s just started here in UK)
Ordering from robotshop is slow may take weeks if they decide so. I once had a order take 4 weeks for 3 things they had in stock. Since they were the only place to have it unless i ordered from china i was stuck. I avoid robotshop as much as i can. Unfortunitly they have a great selection that hasn’t really been matched anywhere.
Just like bg micro i rather get stabbed with a burning poker in my eye then wait for a order update.
Chimp, you are a genius. I will download the code and post all my updates to the project page! By the way, is the 100ohm resistor mentioned on the page really necessary? What damage (if any) could be done?
It is only necessary if you make major changes on code and the servo try to send while FEZ tries to send…this i bus collision and will probably not damage anything but a resistor in place would really make things better. It doesn’t have to be 100ohm, you can use any other value.
Got everything up n’ runnin a few days ago Thanks.
Additionally…
I’ve been searching all a proper listing of registers for any of the GHI hardware; I think i might actually be blind. Where do I go about looking for register documentation? (contextual example: in order to use COM2 instead of COM1 for half-duplex)
it is working and here is the code