As you can see from the video, the LEDs are acting weird. I’m also getting a lot of distortion on output 1/2. I’ve checked for shorts everywhere that I thought might be the problem (and a few places in proximity to those bits) but I’m coming up empty. Anyone have suggestions for further troubleshooting?
Also of note, my laptop spazzed out when I was uploading the hex to the PIC causing the hex to not fully load resulting in some odd characters and weirdness on the sammich LCD. I reloaded the PIC without issue the second time around and everything appears to be cool but, also possibly related; When I loaded the patches to it, it seems to have made every third patch the Rhodes piano patch… which would be awesome if I really needed 50 identical rhodes patches but since I don’t I’d like to fix that too.
Troubleshooting I’ve already done:
Checking for shorts
Looking for inappropriate voltages
regular voltage checks
Correct orientation of all polarized parts
visual inspection of solder joints
continuity tests
cussing
prayer
leave it alone for a few days and hope it gets better
At this point I’m willing to consider incantations, percussive maintenance, advanced cussing, and blood sacrifice as possible solutions but I’d like to get a few more opinions before I proceed with those.
reload of MIOS and re-install of FM firmware did not work. I’m moving ahead with the threats. I’m going to hold a knife to its face for a few minutes, go to bed, and hope it’s better tomorrow. Anyone have another idea?
Try swapping the PIC with another one. Scratch it with the knife first to clearly mark it as suspect #1.
(Note to other builders: I can suggest this to him cos I know he has lotsa sammiches)
The “every nth patch doesn’t get uploaded” could be due to too short time between SysEx blocks, try increasing this to some magic number which I can’t remember, but mine is set to 1000ms which is overkill.
Since we’re both in Portland (and its finally fucking sunny so I’m feeling generous :hug: ) I have 2 PICs that are confirmed working with the firmware installed. You can borrow one to test with if you’d like… PM me if that would help.
Since we’re both in Portland (and its finally fucking sunny so I’m feeling generous :hug: ) I have 2 PICs that are confirmed working with the firmware installed. You can borrow one to test with if you’d like… PM me if that would help.
cheers,
grizz
Thanks Grizz. I think I’m all good on PICs at the moment. I pulled the PIC from the toxic waste green prototype sammichFM (which works great) and put it in the new sammich and it did the ‘every third patch is the rhodes patch’ thing again. That left me thinking it was a short or a mechanical thing that I somehow missed every time I looked at it. I opened it back up, replaced the suspect PIC, and started looking for shorts again. I eventually found one. This bit blew my mind. One of the resistors on the lower row of LEDs was shorted to the adjacent LED cathode. It didn’t show up as shorted because one of the solder spots had a patch of flux where I kept touching the probe. I got the magnifiers out and saw a damn-near microscopic bit of solder bridging the pads. It looked like a reflection. I never would have seen it had I not been super paranoid. I cleaned it up and all the buttons and LEDs worked and the glut of rhodes patches had fixed itself. Totally weird. I guess it happens to all of us every once in a while.
Now I’m just trying to figure out the distortion on out 1/2 but after a 17 hour work day, I’m calling it a night.
Thanks Grizz. I think I’m all good on PICs at the moment. I pulled the PIC from the toxic waste green prototype sammichFM (which works great) and put it in the new sammich and it did the ‘every third patch is the rhodes patch’ thing again. That left me thinking it was a short or a mechanical thing that I somehow missed every time I looked at it. I opened it back up, replaced the suspect PIC, and started looking for shorts again. I eventually found one. This bit blew my mind. One of the resistors on the lower row of LEDs was shorted to the adjacent LED cathode. It didn’t show up as shorted because one of the solder spots had a patch of flux where I kept touching the probe. I got the magnifiers out and saw a damn-near microscopic bit of solder bridging the pads. It looked like a reflection. I never would have seen it had I not been super paranoid. I cleaned it up and all the buttons and LEDs worked and the glut of rhodes patches had fixed itself. Totally weird. I guess it happens to all of us every once in a while.
Now I’m just trying to figure out the distortion on out 1/2 but after a 17 hour work day, I’m calling it a night.
Cool. Funny I just had a similar breakthrough with my recently finished 9090… The Ride Cymbal wouldn’t work, and I could NOT figure out where the problem was. I figured it was a transistor or an IC, not a short or bad solder joint (cause I never do either… :whistle: ) and when I looked at the Ride Cymbal section of the output board for the 10th time I found 1 pad was lifted and therefore breaking the signal path… Oh well, at least it works now!
Cool. Funny I just had a similar breakthrough with my recently finished 9090… The Ride Cymbal wouldn’t work, and I could NOT figure out where the problem was. I figured it was a transistor or an IC, not a short or bad solder joint (cause I never do either… :whistle: ) and when I looked at the Ride Cymbal section of the output board for the 10th time I found 1 pad was lifted and therefore breaking the signal path… Oh well, at least it works now!
Cheers,
Alex
Totally, I’m far too awesome and competent to ever do something as stupid as bridge a pair of pads. Never mind that fact that I did that twice here and had different reasons to not detect either one of them. It turns out that the distortion was due to a loose piece of solder bridging C62 on the top side of the board. So it goes. Everything is good now and sammichFM #2 is working perfectly. Thanks for the help everyone. I’m always stoked at how nice and helpful MIDIboxers are. I’ll post some photos later.
Clearly, the lessons here are:
No matter how big the symptoms, the problem is probably something simple so go back and check it five or six more times.
sammichFM does not respond to threats no matter which MIDI channel they are sent on but, if enough people request it, that feature might be included in the next update.
At least you got to do some troubleshooting… I’ve not needed to on any board I’ve soldered myself in a long time… which is slightly boring. I don’t even bother with voltage tests before plugging in ICs just hoping for a fried IC to locate and replace. *sigh* I suppose it’s a good thing because troubleshooting aka. debugging aka. software development is my day job.
The last time I had some head-scratching WTF moments was with the OPL3 module:
It was nice to take the time to sit down and have a close look at the circuit diagram, trace and test everything back from the output to the power supply, and look closely at every single connection on both sides of the board. When building something I’m usually in a hurry to get it finished or distracted by focusing cameras and recording video that I rarely take the time to be incredibly thorough about checking everything. I’m both amused and relieved that the problem was something obvious and simple obscured by unlikely circumstances. I found the process to be pretty relaxing… but not so relaxing that I’ll ever do it again unless I absolutely have to.
Now, the shiny beautifulness of my girlfriend’s new sammichFM:
OMFG that Optrex LCD looks filth. Great choice of paint colour. The LEDs rock… they look totally opaque and glossy when off, might be just the flash though.
The Optrex LCD is really impressive. The color is really rich and the black is quite dark. The LEDs are indeed opaque white. I’m always on the lookout for low brightness blue LEDs and I bought these under the impression that they were not at all bright. After I received them, I breadboarded a couple and and promptly learned that they were not at all low brightness. In fact, they were some of the brightest 3mm blue LEDs I’ve ever seen. In the end I decided to paint the tops of the LEDs white. I dipped them in some white enamel just to cover the domed part that covers protrudes from the sammich case. It really cuts the brightness while allowing the unpainted portion of the LED to illuminate the translucent panel around the LED. I’m really pleased with the way it turned out. The effect is really cool. I tried a few different colors of enamel to see how the effect differed. Black was too dark, blue looked uneven in the presence of varying paint thickness, but white was consistently great. This sammichFM is for my girlfriend so it was important to me that it look as good as it sounds She saw it last night and totally loved it.
Painted LEDs! I think you just started something big.
I think so. It looks great and it’s easy to do. I’ve got a gnarly week at work coming up, but I hope to get a chance to mess around with the idea a little more and see if I can come up with anything super cool.
Perhaps it’s time to change the title of this topic to ‘sammich behaving awesomely’
@Siempre La Luna: I really like your design and already voted 5 stars for it . May I ask you for the LED brightness? I would like to use white-painted red-glowing LEDs in my sammichFM design, but I’m not sure how bright they should be. I consider using 100mcd ones.
@Siempre La Luna: I really like your design and already voted 5 stars for it . May I ask you for the LED brightness? I would like to use white-painted red-glowing LEDs in my sammichFM design, but I’m not sure how bright they should be. I consider using 100mcd ones.
Best
Martin
I’m glad you like it. The blue ones I used were 200mcd. Blue and white LEDs are way brighter than most red, green, or yellow LEDs so you might want something a bit brighter. I’m no expert though, so it’s probably best to try a few different ones and see which gets the best results. Be sure to let us all know how it turns out.
@Siempre La Luna: Good to hear! If your LEDs are 200mcd bright I sure will be fine with 100mcd. I plan to keep it eye-friendly since 25mcd are bright enough for me, so no need for the 2000mcd ones from Hong Kong :pinch: Thanks for the advice & inspiration and I will keep you updated on how this idea turns out. Probably in the beginning of June I will have the sammichFM readily assembled.
. May I ask you for the LED brightness? I would like to use white-painted red-glowing LEDs in my sammichFM design, but I’m not sure how bright they should be. I consider using 100mcd ones.
