Open Source BDM - Blank ICP

[peg]

Hi all,

I have built the OSBDM and everything works except I can't do a blank part ICP over USB.

I can programme it over MON08 and run it OK

I can get it to enter USB-ICP from there and erase it over USB.

Then thats it, I can't get the device to power up in USB-ICP mode.

Any suggestions???

BR Peg

[RockyRoad]

peg -

There is a note on page 16 of the OSBDM documentation that you may have to  ground reset while you plug in the USB cable, then release reset in order to get into ICP mode. Have you tried this?

[peg]

Hi RR,

Yes I have tried to plug in in reset then release reset and just reset pulse while connected.

I have also tried what I believe the AN2399 is implying which is to power up the board with resistors fitted which allows the mode to be detected and initialised, then connect the two USB signals.

All of these attempts just result in the computer complaining "USB device not recognised" and USBview reporting "DeviceFailedEnumeration: Unknown Device"

Actually today even this doesn't work, yesterday when I powered up the mode seemed to be detected because the internal 1k5 pullup was enabled, today the computer sees nothing as there is no pullup.

If you manually fit the pullup the USB device is seen but not recognised, if you remove the pullup the device dissapears.

Why does this project use an external pullup anyway?

BR Peg

[peg]

Hi,

The last time the device must not have erased properly, I erased it via MON08 and now I am back to the original problem of:

If I setup for USBICP after reset I get the internal pullup on D- but it doesn't seem to initialise the USB ready for ICP.

BR Peg

[irob]

Peg, sounds somewhat familiar, though of course you are using a different programmer than I was.

Just on a whim, can you try different values of pullups on reset? For my system, the sweet spot was 3.3K on reset and background. Also, make sure you have no capacitance on background.

[peg]

Hi Rob,

You said:

Peg, sounds somewhat familiar, though of course you are using a different programmer than I was.

Just on a whim, can you try different values of pullups on reset? For my system, the sweet spot was 3.3K on reset and background. Also, make sure you have no capacitance on background.

Actually its not similar at all, I'm talking about programming the programmer. i.e. a HC08 and using its special blank part ICP over USB. (JB16)

Thanks anyway.

Peg

[irob]

Ahhh, ok. My mistake.