MiguelNoel and me are still doing some improvements on the project, so we redesigned the PCB board with the following changes:
- Replaced wrong ATtiny85 footprint for the proper one.
- Replaced PCB USB for a proper USB connector.
- Replaced through hole joystick for a SMD one.
- Changed PCB shape to fit in a USB plastic enclosure.
- Added two LED to know device status. (suggestions on the notifications and the use of two LED are welcome)
We want to thank al1 for giving us great ideas at https://hackaday.io/page/1468-memtype-testing
The PCB will look like:
Any idea / improvement that won't increment the PCB size or BOM cost too much is welcome !!
Regards,
Noel & Miguel.
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That is looking nice.
To the LEDs: I would suggest to use one for power on / always on if connected and the other for locked(off) / unlocked(on). Maybe you should also think about using a duo LED so that you have third color. And only one hole in the case would be needed.
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Yeah, we will test first prototypes with two different LED (red and a green) separated, but I like the idea of using a red/green all in one smd package, so it will allow us to add a light pipe to the PCB & case.
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Thanks for the prototype--I still haven't gotten to play with it, but it's plugged into my workbench USB hub as a reminder!
I'm not sure you have the space for this as the ATtiny45 only has 4kB program memory, but it's also available in a teeny tiny TSSOP8 package... might be worth checking out to save space?
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Hello Zaqwy, you're right ! ATtiny45 has a TSSOP8 package and the ATtiny85 don't !! The main problem is we can't use the ATtiny45 as the current code takes about 5700 bytes of flash + 2048 bytes for credentials. In order to reduce PCB space the best we can do is to change some 0805 resistors for 0402 ones (depending on power dissipation) and change the uC to QFN package. Currently all the components fit in the PCB so, there's not any real need for reducing PCB space.
Thanks for the suggestion !
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