Pluggy McPlugface

Questions and discussions about assembling a Gigatron kit: from box to baboon. Build photos also!
Forum rules
Be nice.
Post Reply
jbailey
Posts: 9
Joined: 20 Nov 2018, 08:54

Pluggy McPlugface

Post by jbailey » 26 Nov 2018, 06:11

I had assembled my Gigatron and Pluggy McPlugface (PMPF) kits and all seems to be working well. The only thing that give me trouble was the fact that the PMPF kit took approx. 30-50 seconds to start up (or at least initialize the keyboard). The game controller is usable as soon as the menu is up (1-2 seconds for power is applied), so I am assuming their is a longer boot time on the AT85.

After that initial delay all works well, is this usual?

User avatar
marcelk
Posts: 283
Joined: 13 May 2018, 08:26

Re: Pluggy McPlugface

Post by marcelk » 26 Nov 2018, 09:45

PS/2 keyboards contain a microcontroller that, at power-on, performs a self-check called "BAT". After succesful BAT, they momentarily flash their LEDs and all is good.

Some keyboards (not all) want to draw more current in this phase than is available. This may then either result in not getting through BAT at all, or requiring several attempts if you're lucky. This can take a couple of seconds, sometimes even up to a minute.

Experimentally we've found that sending 'Enable' commands back into those keyboards can help them boot up a lot faster, so the ATtiny85 does that. But for some keyboards even that won't help, and their lights never light up. YMMV. Lower-power keyboards boot up immediately.

jbailey
Posts: 9
Joined: 20 Nov 2018, 08:54

Re: Pluggy McPlugface

Post by jbailey » 26 Nov 2018, 15:37

Thank you for that detailed explanation. At first I wasn’t waiting long enough as I figured something was wrong but I couldn’t find an assembly error. Then I noticed the delay, it’s varies a bit but is consistent.

It may be helpful to publish a few recommendations for keyboards that are low power (as you hear from others). If I find one I’ll post it too.

That said this is a really cool upgrade that drastically expands the Gigatrons possibilities.

Thank you a interesting kit with a lot of learning possibilities baked in.

Post Reply