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Getting G3 Whisper Perch USB working

Posted by: Phipli on 2023-03-21 17:30:26

View attachment 53995

We need to populate one of these to get 3.3V, if one isn't already populated??

Couple more caps worked out here :
View attachment 53996

The Max1615 is shown set to be a 3.3V regulator, so I believe that should be a 78L33, not a 78L05.

Posted by: croissantking on 2023-03-21 18:02:09

Posted by: cheesestraws on 2023-03-21 18:02:45

Ooooh!

Posted by: croissantking on 2023-03-21 18:06:32

Swapping in those other caps got it going!

What a great team effort.

I couldn’t actually find any 47pf caps, so I used 200/300 pf ones, but it seems they were close enough.

I’ll have to do some testing - it might not be fully reliable yet.

Posted by: croissantking on 2023-03-21 18:45:20

@croissantking
I recommend getting one of these :

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It will help you work out what the caps and inductors are.

I'll order one... but... just wanted to ask, how would you test those tiny SMD caps? Do you solder it in somewhere? Because the pictures show through-hole components being tested.

Posted by: Fizzbinn on 2023-03-21 18:56:27

Swapping in those other caps got it going!

What a great team effort.

I couldn’t actually find any 47pf caps, so I used 200/300 pf ones, but it seems they were close enough.

I’ll have to do some testing - it might not be fully reliable yet.

OMG! Awesome!!! Congrats guys!

Posted by: croissantking on 2023-03-21 18:58:32

So my initial tests are that the keyboard works perfectly, but plugging something into either of its powered USB ports causes the keyboard to stop working. Unplugging the extra device allows the keyboard to come back to life.

A Logitech USB receiver and mouse almost works perfectly, but some of the clicks are lost - the mouse pointer has to be moving for the clicks to register. There seem to be errors building up in the log as this happens.

A USB CF card reader is detected but won't mount my CF card.

A USB Scanner is detected, but won't work.

There also seem to be some issues with unplugging one device and then plugging in another and the USB bus hanging, requiring a restart.

I think we just need to work out the values of those other caps now.

Posted by: croissantking on 2023-03-21 18:59:44

OMG! Awesome!!! Congrats guys!

Thanks! Yes, it is awesome!

Posted by: croissantking on 2023-03-21 19:32:12

Does this offer a clue as to the value of C113?

-----

If this refers to the caps around the USB chip that are connected to its VCC and VSS pins, I'll need to double check them as I've used 0.1uf on all of them but some need to be 10 uf.

Posted by: jeremywork on 2023-03-21 21:53:27

View attachment 53999

I know it needs refining still, but this is very cool to see. Nice work!

Posted by: Phipli on 2023-03-22 01:04:36

I'll order one... but... just wanted to ask, how would you test those tiny SMD caps? Do you solder it in somewhere? Because the pictures show through-hole components being tested.

You push them down on the pads that look like a SOT package regulator, or put jumper wires in the socket.

Posted by: Phipli on 2023-03-22 01:05:09

Swapping in those other caps got it going!

What a great team effort.

I couldn’t actually find any 47pf caps, so I used 200/300 pf ones, but it seems they were close enough.

I’ll have to do some testing - it might not be fully reliable yet.

Congratulations 🙂

Posted by: Phipli on 2023-03-22 01:08:37

View attachment 54003
Does this offer a clue as to the value of C113?

-----

View attachment 54004
If this refers to the caps around the USB chip that are connected to its VCC and VSS pins, I'll need to double check them as I've used 0.1uf on all of them but some need to be 10 uf.

I need to find a layout as well, which I think is what Cheesestraws found. To see where those caps go.

Posted by: zefrenchtoon on 2023-03-22 01:39:20

Wow! You did it !!

Congratulations !!

What a thrilling adventure ! 😀

Posted by: cheesestraws on 2023-03-22 02:03:06

I need to find a layout as well, which I think is what Cheesestraws found. To see where those caps go.

Yes, there's a PCB layout also on that page for an example 2-port USB card. Unfortunately in orcad format and I don't have anything that can read that.

Posted by: Phipli on 2023-03-22 02:06:33

Minor update.

You need to include the other caps you added for me to continue making updates.

(FB is Ferrite Bead)

Posted by: cheesestraws on 2023-03-22 02:09:08

A Logitech USB receiver and mouse almost works perfectly, but some of the clicks are lost - the mouse pointer has to be moving for the clicks to register. There seem to be errors building up in the log as this happens.

What're the errors?

Posted by: Phipli on 2023-03-22 03:21:43

anyone got a way to read OrCAD 9 files? opti's website has an application schematic of an example board (http://www.opti-inc.com/html/usb1394.html or attached below).

Friend opened the archive, looks like another version of the schematic.

Posted by: cheesestraws on 2023-03-22 03:24:51

Friend opened the archive, looks like another version of the schematic.

Above that on the page (2p861tmp.zip) there's a file that claims to contain gerbers, at least.

Posted by: Phipli on 2023-03-22 03:36:43

Above that on the page (2p861tmp.zip) there's a file that claims to contain gerbers, at least.

Yup, just spotted them. Here is the top silkscreen for component placement W.R.T. the schematic. We should have everything, differences from the reference design aside.

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