core/lcd/hex problem

[jbartee]

Hi everyone,

So a few days ago I finished wiring up a a core module and two sid modules (both from smashtv). At first everything seemed to be going smoothly; all the voltage tests were good and when I stuffed the IC's and hooked up my LCD I got a nice big "READY." I then proceeded to hook the core up to my computer to upload the midibox sid hex files, and ran into my first problem. The core sends an upload request which MIOS studio receives, but then it immediately hits checksum errors and midi in overruns when attempting to upload the first hex block. For refference, I'm runing the latest version of MIOS studio on snow leopard 10.6.2, with Mandolane installed. Midi seems to be working.

In order to solve this I tried a couple things. I had read something funny about the LCD possibly affecting sysex reliability so the first thing I did was solder a 1k pull up resistor between +5 volts and d03 of j15, as per this schematic: http://ucapps.de/mbhp/mbhp_lcd_4bit_mios8.pdf . This had no effect. Then I thought perhaps I had wired up the connection from the core to the sid modules incorrectly, so redirected SC to SC instead of to MD. I now realize this was an error. I have restored it so it is once again SC to MD.

Throughout these alterations everything remained fine. Then after a minute of having the machine off I went to turn it back on and... boom. No readout on the LCD. It just hovers at the block character screen and never gets to the mios boot up/ready screen. I have no idea what caused this. I have been over the connection from the core to the LCD meticulously with my multimeter and everything checks out. What's funny is that the PIC is still sending out upload requests every two seconds, so it at least seems to have some life.

I am completely stumped at this point and am in desperate need of some assistance. Have I fried my PIC, my LCD, or both? Also, assuming I can fix my current problem with the core, I still need to figure out why I can't upload hex files to begin with.

Thanks in advance,

Jordan

[philetaylor]

Hi.

The "block character screen" just means that the LCD has power but has not been initialized. The fact that you are getting an upload request every 2 seconds means that the MIOS bootloader is running but you may have erased/corrupted MIOS, as it isn't booting.

This isn't a problem but you will need to (re)upload MIOS to the CORE before you can upload the SID app again.

I don't think that you have fried anything but it is worth checking all connections!

Cheers

Phil

[philetaylor]

I forgot to mention, also try going through this process to debug your CORE/MIDI connection: http://www.ucapps.de/howto_debug_midi.html

Cheers

Phil

[jbartee]

Hi.

The "block character screen" just means that the LCD has power but has not been initialized. The fact that you are getting an upload request every 2 seconds means that the MIOS bootloader is running but you may have erased/corrupted MIOS, as it isn't booting.

This isn't a problem but you will need to (re)upload MIOS to the CORE before you can upload the SID app again.

I don't think that you have fried anything but it is worth checking all connections!

Cheers

Phil

Thanks for getting back so fast. If it's simply corrupted firmware then that's a major relief. Out of curiosity and a desire to avoid similar occurrences in the future, how might this have happened? Simply turning the core on and off too quickly perhaps?

So assuming it's a matter of uploading MIOS, I'm back to my original problem of screwed up sysex. I guess I could try a different interface/operating system, but I'm basically stabbing in the dark on this issue. Any ideas?

[jbartee]

I forgot to mention, also try going through this process to debug your CORE/MIDI connection: http://www.ucapps.de/howto_debug_midi.html

Cheers

Phil

Okay. I've been slowly working through this document already, to no avail so far. But I still have some checks left to do. I'll report back when I've troubleshooted everything. Thanks!

[philetaylor]

The most common cause of a corrupt MIOS is a partially uploaded app. If the app started uploading it is possible that your computers MIDI port couldn't keep up with the sysex transfers and that is why you started getting checksum errors. What type of midi interface are you using? It isn't one on the "MIDIbox blacklist" is it??

http://www.midibox.org/dokuwiki/doku.php?id=midi_interface_blacklist lists the interfaces that don't work properly with MIDIbox, usually because they can't handle sysex very well!

Cheers

Phil

[jbartee]

The most common cause of a corrupt MIOS is a partially uploaded app. If the app started uploading it is possible that your computers MIDI port couldn't keep up with the sysex transfers and that is why you started getting checksum errors. What type of midi interface are you using? It isn't one on the "MIDIbox blacklist" is it??

http://www.midibox.org/dokuwiki/doku.php?id=midi_interface_blacklist lists the interfaces that don't work properly with MIDIbox, usually because they can't handle sysex very well!

Cheers

Phil

I was using an m-audio FireWire 410. With the switch to snow leopard, it has a brand new 64bit driver that still has some kinks in it... perhaps that could be affecting it. The only other midi interface I have is a BCR2000, which is on the blacklist, but only listed as problematic for OS X? I might try it on my girlfriend's PC and see if it works.

[philetaylor]

A quick Google search reveals this: http://forums.m-audio.com/showthread.php?14110-SL-10-6-2-FW410-Problem-with-Outgoing-Sysex-messages

It does look like there is a problem sending Sysex in the 1.9.2 and 1.9.3 drivers with Snow Leopard!

Cheers

Phil

[jbartee]

A quick Google search reveals this: http://forums.m-audio.com/showthread.php?14110-SL-10-6-2-FW410-Problem-with-Outgoing-Sysex-messages

It does look like there is a problem sending Sysex in the 1.9.2 and 1.9.3 drivers with Snow Leopard!

Cheers

Phil

Thank you. Don't know how I missed this. I just finished everything on the midi troubleshooting page except for the last few hardcore loopback checks. I will proceed on the assumption that the boards are fine and try to upload MIOS using another interface and/or operating system.

Thanks again!

[jbartee]

I just wanted to report back that I got everything working. After trying several midi interfaces, an old Evolution U-Control UC-33 that I borrowed from the university finally did the trick. I actually used the midi in from the FireWire 410 and the midi out of the U-Control in concert; an odd solution but if it works it works! MIOS as well as the sid application are uploaded and working splendidly.

Just a heads up for other newbs, that 1k pull up resistor I mentioned at the beginning of the thread is essential. Without it the core gets locked in some kind of (I'm guessing) brown out reset pattern whenever it tries to load the control surface. I thought I'd mention this because if you're working off smash's boards, there's no dedicated spot in the layout to wire up this resistor and as far as I can tell it's not mentioned in his assembly guides.

[Labelwhore]

Just a heads up for other newbs, that 1k pull up resistor I mentioned at the beginning of the thread is essential. Without it the core gets locked in some kind of (I'm guessing) brown out reset pattern whenever it tries to load the control surface. I thought I'd mention this because if you're working off smash's boards, there's no dedicated spot in the layout to wire up this resistor and as far as I can tell it's not mentioned in his assembly guides.

oh my, that sound like the problem with the Smash kit I set aside a while back. This sounds like an excuse to get started on it again. Thanks for the info!