OpenServo.com

ginge · Posted: Fri Feb 15, 2008 9:30 pm Post subject:

Other than the I2C lines not working, you will definitely have issues running from 5.5v The onboard 5v regulator needs at least 1.2v above the 5v in order to function within normal parameters. That means at least 6.2v

I ave no idea why the I2C lines are not working. Try removing the pullup resistors and scoping the pins directly.

Barry
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enigma460 · Joined: 12 Feb 2008 Posts: 23

I tried 9v but with the same results.

Now, you mentioned that the I2C buss may be locked and that causes and endless loop. Then windows disconnects the usb device.

But when I run USBview the device is still connected and there is activity on the usb port.

Question. Can I attach a 24c65 eeprom to the OSIF. ??? Will it detect it?? This would be a test since I know the eeprom is working. Process of elimination.

Thanks

ginge · Posted: Sat Feb 16, 2008 5:43 pm Post subject:

Hi,

The OSIF is a generic USB to I2C bridge, so any I2C device will work. If you are using the testapp you will see it appear in the "Other" section, but you will not be able to interact with it unless you use the "generic comms" section.

You mentioned you scoped the output, and you saw nothing. Even with no devices connected you should see the SCL clock and SDA data lines doing something.

Here is a scoped image with nothing connected to an OSIF

This is showing no activity on the SDA line as my scope was set to a different range, but you should see similar to the below image.

And with a device connected:

If you are seeing nothing at all on the I2C lines when nothing is connected, there is an issue, and I am not sure what to recommend.

Barry
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http://www.robotfuzz.co.uk/

enigma460 · Joined: 12 Feb 2008 Posts: 23

Well, I don't get anything like that.

I have used 2 other Atmega 8's and one Atmega 168 and the same thing happens.

Connected to PC and USB OK
Both I2C lines high state, no activity. with or without resistors.
Nothing Connected to I2C buss
Start up Openservo, Scanbus
Both I2C lines low state, no activity, with or without resistors.
Nothing connected to I2C bus

Very strange

Tempted to switch over to the PIC line and create a serial to I2C device.

ginge · Posted: Sat Feb 16, 2008 7:12 pm Post subject:

Lets check some assumptions on my behalf, and update so I know where you are at.

you see a device on ID 1964 0001 and not 0403 6666

your I2C lines are pins 27 & 28 (last ones at notched end)

when you scope the pins directly, nothing happens, with or without the resistor. You are not tying the SCK line to the I2C at any point, not that it matters.

you see the OSIF detected in the openservotest application but nothing shows up on a scan, and there are no obvious errors in the debug window.

You are logged in as administrator, or an administrator user.

The OSIF dll is in the same dir as the app

Can you confirm?

B
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enigma460 · Joined: 12 Feb 2008 Posts: 23

Lets check some assumptions on my behalf, and update so I know where you are at.

you see a device on ID 1964 0001 and not 0403 6666

Correct

your I2C lines are pins 27 & 28 (last ones at notched end)

Correct

when you scope the pins directly, nothing happens, with or without the resistor. You are not tying the SCK line to the I2C at any point, not that it matters.

Plug in OSIF to USB on PC
USBview identifies device, so driver is loaded.
Pin 28 and 27 are at a high level, 5 volts, no activity
Run Openservo
Openservo Sees OSIF and continues scan
Pin 28 and 27 go low level, 0 volts, no activity
Nothing connected to Pin 27 or 28

you see the OSIF detected in the openservotest application but nothing shows up on a scan, and there are no obvious errors in the debug window.

Correct

You are logged in as administrator, or an administrator user.

Correct

The OSIF dll is in the same dir as the app

Correct

Can you confirm?

ginge · Posted: Sun Feb 17, 2008 1:45 am Post subject:

I just uploaded a new .hex file to the version 2 firmware CVS directory. See if that helps any.

You could also try the version 1 firmware which is slower, but shouldn't matter for a test of the hardware

Barry
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http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/

enigma460 · Joined: 12 Feb 2008 Posts: 23

Nope, No change.

I'm going to step back from this for a moment and collect my thoughts.

I'd like to thank you for your time and patience in this matter.

I'll update here if any progress is made.

ginge · Posted: Sun Feb 17, 2008 11:03 pm Post subject:

Probably just as well as I am fresh out of ideas. I thank you for trying all of the things above and sticking with it.

Good luck in the path you choose.

Barry
_________________
http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/