Issue with building my own Pluppy McPlugface

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maded2
Posts: 6
Joined: 26 Jul 2020, 02:22

Issue with building my own Pluppy McPlugface

Post by maded2 » 26 Jul 2020, 03:26

hi all,
I've built my own Gigatron SBC and Pluppy McPluface using own sourced PCB and parts. The Gigatron is working fine and but I can not seem to get the Pluppy McPlugeface to work. I am using a ATTINY85-20PU part from Element24. I burn the fuses and rom image (see below). I've checked the voltage on the AT85 and everything looks good. I am using an wired PS/2 keyboard. If I hit lots of keys then it sometimes select Snake, but I can't control it. The arrow keys don't work.

Does anyone have any suggestion on what else I should test?

BTW, I've tried both BabelFish.ATtiny85.bin & BabelFish.ATtiny85_v1.bin rom images from Github without success.

thanks.
eddie
eddie  desktop1  ../Utils/BabelFish  minipro -p attiny85 -w BabelFish.ATtiny85_fuses.txt -c config
Found TL866II+ 04.2.115 (0x273)
Warning: Firmware is out of date.
Expected 04.2.116 (0x274)
Found 04.2.115 (0x273)
Chip ID OK: 0x1E930B
Writing fuses... Could not read config fuses_ext value.

eddie  desktop1  ../Utils/BabelFish  minipro -p attiny85 -w BabelFish.ATtiny85_v1.bin -s
Found TL866II+ 04.2.115 (0x273)
Warning: Firmware is out of date.
Expected 04.2.116 (0x274)
Found 04.2.115 (0x273)
Chip ID OK: 0x1E930B
Warning: Incorrect file size: 8064 (needed 8192)
Erasing... 0.01Sec OK
Writing Code... 1.04Sec OK
Reading Code... 0.41Sec OK
Verification OK

at67
Posts: 202
Joined: 14 May 2018, 08:29

Re: Issue with building my own Pluppy McPlugface

Post by at67 » 26 Jul 2020, 06:00

Have you tried multiple PS2 keyboards? Not all of them are 100% compatible, especially USB keyboards with internal/external PS2 adapters.

viewtopic.php?f=4&t=223
viewtopic.php?f=4&t=95
viewtopic.php?f=4&t=62
viewtopic.php?f=4&t=74
viewtopic.php?f=4&t=71

maded2
Posts: 6
Joined: 26 Jul 2020, 02:22

Re: Issue with building my own Pluppy McPlugface

Post by maded2 » 26 Jul 2020, 06:45

forgot to mentioned that I do see the Wired PS/2 Keyboard flashed the 3 LEDs on power up. So the keyboard to be initialized.

eddie

jbailey
Posts: 27
Joined: 20 Nov 2018, 08:54

Re: Issue with building my own Pluppy McPlugface

Post by jbailey » 28 Jul 2020, 04:44

I had no end of issues with the PluggyMcPlug face adapter for the Gigatron. Since the Gigatron was the only computer I owned that used a USB keyboard, I purchased an inexpensive PS/2 keyboard. Sometimes it would work right away, other times it may initialize after 20-30 seconds. Then I had a 2nd keyboard that worked a couple of times and then stopped working on the Gigatron (but worked on a PC with a PS/2 port).

I built two more PluggyMcPlug faces thinking I may have static damaged them, overheated the AT85, or something. I tried different assembly techniques all to no avail.

What I found out was the following:

* Make sure your Gigatron works with the included Gamepad (if you built your own based on the twitter post, make sure your gamepad is a 5v version and not a 3v device).
* Make sure your USB power cord is of high quality, as you want to minimize the voltage drop in the system (don't use the one from the kit)
* Measure VCC/GND on the AT85 to ensure you are getting something really close to 5 volts. If you have a lab power supply try increase the voltage by .05 to .1 and see if that helps.
* Also keep in mind that while some USB keyboard have the electronics and firmware to support PS/2 using an adapter not all of them do. Even some of the USB keyboard that will work with a PS/2 adapter rarely indicate it.

I purchased a Logitech PS/2 Classic Keyboard K100, it wasn't cheap but it works very well and EVERYTIME.

I then took apart both of the other keyboards and found the gauge of the cable used was so small that it cased a .4 volt drop by itself. So this means that the keyboards microcontroller was getting between 4 - 4.5v and didn't work reliability (depending on which USB power cord and power adapter I used)

The funny thing is once I got a quality keyboard all of the other Pluggys worked well too. If you have an scope you can probe the pins used on the AT85 for tx and rx and press keys and you should see a very specific pattern. it will be the byte value of ascii equivalent of the key, this will tell you if the AT85 and the keyboard are able to communicate at all.

Hopefully this helps, best of luck :-)

walter
Site Admin
Posts: 91
Joined: 13 May 2018, 08:00

Re: Issue with building my own Pluppy McPlugface

Post by walter » 28 Jul 2020, 07:04

Thanks for your debugging work! Good to hear everything is now working fine.

For some earlier kits, the cable is not the best quality. All the later kits have 28 AWG USB cables that work perfectly (either white or black).

USB keyboard *should* support PS/2, but not all work according to specification. Unfortunately, you cannot tell by looking at it.

klf
Posts: 10
Joined: 10 Jan 2019, 22:48

Re: Issue with building my own Pluppy McPlugface

Post by klf » 28 Jul 2020, 12:36

USB keyboards from the transition time, when PS/2 was still common, often support both protocols. Newer ones do not. If your USB keyboard came with a green PS/2 adapter it should work. If no adapter was included it is unlikely that this protocol has been implemented.

maded2
Posts: 6
Joined: 26 Jul 2020, 02:22

Re: Issue with building my own Pluppy McPlugface

Post by maded2 » 29 Jul 2020, 13:20

thanks for the reply. I planned to use a scope to look at the AT85 this weekend. I've checked the voltage and they all look fine. Also, I may buy another PS/2 keyboard and try that as well. I didn't built the Gogatron from the kit so I don't actually have a game controller.

thanks,
eddie

walter
Site Admin
Posts: 91
Joined: 13 May 2018, 08:00

Re: Issue with building my own Pluppy McPlugface

Post by walter » 29 Jul 2020, 17:11

More info on compatibility:

https://en.wikipedia.org/wiki/PS/2_port ... /2_and_USB

So you can use:
- USB keyboard that also supports PS/2 (probable pre-2010) with any USB-PS/2 converter
- USB keyboard that does not support PS/2 in combination with an active converter (post-2010)

Passive adapters are normally in a plug format.
Image

Active adapters normally have 2 PS/2 plugs (keyboard/mouse) that connect to a little black box with cables.
Image

maded2
Posts: 6
Joined: 26 Jul 2020, 02:22

Re: Issue with building my own Pluppy McPlugface

Post by maded2 » 31 Jul 2020, 11:19

I've tried 3 keyboards now and it still not working; PS/2 wire and USB with passive adapter. I am wondering, I am running Rom v5a, is there compatibility issue with Pluggy McPlugface running BabelFish.ATtiny85_v1 ?

delpozzo
Posts: 24
Joined: 03 Jun 2020, 18:47

Re: Issue with building my own Pluppy McPlugface

Post by delpozzo » 31 Jul 2020, 17:08

I've tried 3 keyboards now and it still not working; PS/2 wire and USB with passive adapter. I am wondering, I am running Rom v5a, is there compatibility issue with Pluggy McPlugface running BabelFish.ATtiny85_v1 ?
This reminded me of a post I saw from Marcel:
viewtopic.php?f=5&t=233&p=1469&hilit=attiny85#p1469
marcelk wrote:
16 May 2020, 09:20
...

PS: People having trouble loading and saving though Babelfish with MS BASIC in ROM v5a probably have forgotten to update their Pluggy McPlugface firmware: BabelFish.ATtiny85.bin

From my command line I type

Code: Select all

make burn85
I updated my ATtiny85 20U via the Arduino IDE and uploaded the latest BabelFish to it using this adapter:
https://www.sparkfun.com/products/11801

Image

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