Rave

Hi all, I've had a look through the forum, but can't seem to find what i'm looking for. I'm after a replacement LCD with backlight for my Sammich, I know its a 20x2 using the HD44780 protocol, but they seem hard to track down in the UK? I've tried an OLED, but found through reading the forum they are pretty much a no go. I did get a replacement from poland which is electrically compatible, but not mechanically and doesn't fit in the PCB properly, so I was just wondering if anyone knew where I can source one for a reasonable price that is electronically and mechanically compatible? Thanks :)

is there a version or way of doing this on a pc with windows 10? Google yielded little results on the subject!

Hi All, Just thought i should write an update to this topic. I have had an electronics engineer look at the sammich, and i am really happy to say that it now work perfectly as far as i can tell :) I have it hooked up to my AN1X making all kinds of awesome sounds and sequences. The problem turned out to be a very elusive one to track down, The guy that looked at it tested the optocouplers and they were all fine, even the ones i had that were thought to be blown. In the end it turned out to be a trace on the PCB about 2-3mm long that simply wasn't there to begin with, so its a possible PCB manufacture fault on my board. The trace has been traced and to end now and a jumper cable fitted in between, and the sammich is now functioning normally! the only thing thats not so great now is my MIDI knowledge, as it was nearly 6 years ago when i started the build, and i knew a lot more and used more MIDI devices back then and even had a little home studio, but life changes and now i dont, but i guess i now have the fun of trying to learn all over again, hopefully it won't be too hard! Anyway, i am delighted to finally have it working after al this time, what an awesome little machine it is. Thanks to everyone thats helped me out in the thread and RL trying to get this little box going. :)

@C_04, Rowan has disabled the backlight on the LCD and has said that the box is now functioning correctly, so Im looking at getting a new LCD display, as that may be the issue. I found an OLED which has identical specs and have had it confirmed by one of my friends who's into electronics hardware, which should draw less power as well, so once I have the box back I'm gonna try that and see if it helps. Ill post back once i have the box and have replaced the display.

Hi Rowan, That could be an issue, the guy i had look at it here said the same thing, he has taken the schematics and had look, and the only thing h has said so far is that lots of parts are very close to their tolerances based on the circuit diagram and components. I really appreciate you taking the time to look at it for me Rowan, I hope that it's repairable and nothing too major wrong with it. Thanks, Kai.

It does seem a bit odd, and possibly indicative of a problem somewhere else, maybe too much current is getting to it, it's being spiked somehow? I am wondering if a higher quality optocoupler might be in order, i've spent a few hours looking at datasheets etc this morning, and am wondering if the toshiba one listed below may be better than the replacements i bought? I know they all pretty much do the same thing, but i'm wondering if a higher quality part might be a bit more resilient/tollerent? Of course this is pure speculation, and I don't actually know. http://www.amazon.co.uk/OPTOCOUPLER-DARLINGTON-6N138-TOSHIBA-Square/dp/B008AHIHY6/ref=sr_1_1?ie=UTF8&qid=1434966817&sr=8-1&keywords=6N138 http://www.ebay.co.uk/itm/OPTOCOUPLER-DARLINGTON-O-P-Part-TOSHIBA-6N138-/390813577029?pt=LH_DefaultDomain_3&hash=item5afe4def45

Hi Rowan, Thanks for letting me know, that is a bit weird as I bought 2 new ones and tried it with them both? One of which was in the sammich as sent, and the other I put in the box in a sealy bag. Is it possible I got duff optocouplers? Are they are being fried somehow? Does it work with the usb to midi cable as well? I'm at a bit of a loss as to why that would happen again? Thank you for having a look, and confirming that was the fault. Any ideas why it might be going through optocouplers? Thanks, Kai.

Hi Rowan, Thank you very much :-) I appreciate your time and there is no rush my end for it. You probably noticed I included all the cables I've been using. Please let me know as and when if there are any parts or time costs and I will of course reimburse you :-)

Hi Rowan, I do still have your details, It would be amazing if you could have another look at it for me, I would be really really grateful. I can get it packaged up and posted up to you this weekend if that's ok? Goes without saying, but I am more than happy to pay for all shipping, parts and time. Many Thanks, Kai.

Hi Walter, Thanks for the advice, I have purchased and changed over the optocoupler as this was identified as a problem previously, I bought a few and have tried them all! Rowan was able to get it to flash the MIOS, and apart from it having damaged SIDs at the time it worked, SIDs have now been replaced for fully working ones, so i really think the issue may be somewhere between the MIDI port and main PIC, but I simply don't know enough to test. I am trying to go through the troubleshooting page on the wiki at the moment, but if i'm completely honest i've lost heart in the project. So, If anyone one can help me, Please do!

Hello All, I have been having a few issues with my Sammich since I finished it, see posts here: I have been over the board with a fine tooth comb, and cannot see any visible issues, the board has also been completely electronically tested and belled out, and anything that was wrong fixed, so i'm fairly sure it is not an electrical issue. Also the patches play absolutely fine when triggered from the buttons on the Sammich, and you can noodle around with the settings and change values as you would expect. The problem is that no matter what controller, keyboard or DAW i use, I cannot seem to perform the simplest task of pressing a key on a keyboard and have it play on the Sammich! I have taken it to a few friends that have more MIDI knowledge than me, and they can't seem to get it to do anything either, other than occasionally get it to play the odd note, or have it jump around from through the patches. (i think it might be a sysex/cc thing, but I don't know enough about the inner workings of MIDI to be sure). Basically what I would really like is if someone in the UK (or Nearby in Europe) could take a look at it and just verify that it actually works in a MIDI setup, and that notes can be triggered, and things are working as they are supposed to, and that it is infact my complete lack of MIDI knowledge at fault and not the Sammich (or if it is the Sammich, at least I know and won't go insane, and can try to fix it.) I really am at the end of my tether with this and have honestly done absolutely everything I am capable of to get it working, so if someone is able to help I am happy to pay for all shipping and any parts and time if required. Please help me keep my sanity! Thanks, Kai.

I can confirm the optocoupler and both SID's have been replaced, the optocoupler was new (I do have a spare I can test with though, so I might try that first) The original SID's had issues with filters and some other weirdness, but the new ones in there now have no problem and sound fine, and have been tested in a C64 with the test SID app. Honestly, I'm a bit at my wits end with this now :( I am wondering if there is anyone that would be able to have a look at the sammich for me, as clearly I don't seem to have the skills to make it work, I am happy to pay for someone's time and return postage if anyone can help. Thanks, kai. [edit] I have replaced the optocoupler with a new one just in case, but still have the same issues. I will start progressing through the troubleshooting guide and see how it goes.

Hi all, Please go easy on me, I am new to MIDI and Sammich! I have built a Sammich a few months ago now, and was having problems flashing it, Rowan kindly had a look at it and between him and TK it was fixed (bad optocoupler) Rowan flashed the MIOS and patches for me and I replaced the opto coupler, and bought 2 new SID's as the existing ones were both slightly faulty, now its up and running and the Sammich sounds great triggering the patches from the buttons on it's front panel. Now, here comes the problem: I have wanted to hook it up via MIDI so I can play the patches with a keyboard, which i think should be fairly straight forward based on other MIDI devices I have used. When I hook up the Sammich to my controller keyboard I set it to send on channel 1, I also make sure in the patch on the sammich, in the menu that it is set to also use channel 1, I play the keyboard and nothing happens, I cycle through patches and make sure they are on channel 1 also, but still nothing? I have also hooked the sammich up to fruityloops via a Umidi USB cable (as suggested by the whitelist) and set fruity to output on channel 1, now this does strange things, sometimes the patch will trigger or play randomly or sometimes it causes the sammich to cycle through patches randomly? I have midi out on the keyboard and or fruityloops to midi in on the sammich. I have taken it to a friend who is a bit more knowledgeable with MIDI than me, and he has had a play and thinks there may be an issue with the sammich not properly responding to the midi information, and possibly miss translating what it is receiving. Could this be me just not knowing enough about MIDI, or is there potentially another issue with the sammich that needs correcting, like with the faulty optocoupler? Any help appreciated, and if someone could confirm the best way to make sure it is receiving MIDI and translating it properly that would be great. Thanks, Kai.

HI Rowan Just wanted to say thank again for flashing the sammich. I've had some time to play with it now and i think one of the sids is partially damaged, hence the strange some patches mono and some drumkits only partly sounding, so i've ordered a new pair of 8580's and will fit them when i get them and hopefully this will fix the issue. I haven't had a chance to wire it up to midi yet, but a friend at work did today but his keyboard wouldn't play it but his novation would! go figure. Anyhow, once its all up and running with the new sids i'm going to take it to my midi loving friend and see what we can do. Thank you so much for all your help.

Thank you so much Rowan :smile: I look forward to getting it back and finally being able to try it after about 4/5 years of being parts! And thanks to Thorsten and KPete for the help with diagnosis, what a fantastic community :D