Swine Posted October 4, 2008 Report Share Posted October 4, 2008 Ive been lurking on this site for about 6 months now and finally built my first core module! I have followed MANY VERY helpful pdfs and posts explaining how to neatly wire a lcd screen with ribbon cable and how not to screw up ect. So i finally have my core and have tested the vdd going through it at the designated spots, every reading is 5.68v. and my initial reading if i put the volt meter on J1 is 16.79. then when i plug the lcd screen in the vdd readings show up to be 5.76 and te j1 reads 14.68v. I am a little confused though becuase my wallwort (not sure on spelling) says taht it is pumping out 9v... not sure how im gaining those extra volts... maybe my power supply (which is a cheep variable one) is a little wonky. as of now i know little about electricity but am fast learning (in university as well as the internet), so to all of the very helpful people on here i would like to know if its ok to be plugging the pics in. I'm very anxious to do plug everything but rather not mess every thing up and have to reorder. i know the pics are fairly robust but im very much the better safe than sorry person. Thanks so much for the help and i hope ive written a good first post that won't warrent the "search the forum" answer (as i have been on this forum more than my parents and professors even doctors would agree to be the healthy amount ;D) Quote Link to comment Share on other sites More sharing options...
nILS Posted October 4, 2008 Report Share Posted October 4, 2008 5.7V is a bit too much after the regulater, just as 14V is too much before the regulator. Try to put some load on the circuit (and LED + resistor) and see if the voltage on J1 and J2 drops to acceptable values. If not - get a new wallwart. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 4, 2008 Report Share Posted October 4, 2008 I'm guessing a dodgy multimeter might be playing a part in this.... Take nils' advice, but don't place too much faith in the meter, they're always a little inaccurate. Quote Link to comment Share on other sites More sharing options...
Swine Posted October 4, 2008 Author Report Share Posted October 4, 2008 few, good thing i didnt plug it in. Ill be putting leds on it later today after i get back from lovefest ;D. but im pretty sure that the multimeter could be dodgy considering it was my grandfathers pocket micronta, its only from 91 or so but i dont know what its been through. When the pic is plugged in is it possible that it will be closer to 5v then? just out of curiosity what would be an ok margin for error? 5.3v? Thanks for your help and hopefully my question hasnt been brought up too many times Quote Link to comment Share on other sites More sharing options...
lylehaze Posted October 4, 2008 Report Share Posted October 4, 2008 Good First Post. Welcome aboard!If you are using a 7805, the regulator is probably more accurate than the meter. I doubt you will have any problems.If it is a digital meter try changing the battery in the meter. Digitals often read high when the battery is low.If it's not a digital meter, how are you getting readings to two decimal places? ::)Wall wart transformers often give higher voltages than expected, the labels are not to be believed. If the regulator doesn't get too hot under full load, then you'll be fine. If gets too hot to touch, you can either feed it a lower voltage or attach a heatsink.Have Fun,LyleHaze Quote Link to comment Share on other sites More sharing options...
Swine Posted October 6, 2008 Author Report Share Posted October 6, 2008 I put a resistor or two before j1 (was this stupid) to reduce teh voltage and then decided to plug everything. Just to try and be as explicit as possible I've built the most recent (i am assuming since i bought it 1 month ago) Smash tv core kit, with a 4620 pic. So it does have the 7805 regulator. I've tried plugging the pic and optocoupler in and my LCD screen does not change from its blue led backlight. a normal person would have just said that the "ready" message does not show up on teh screen, but oh well and i am at least getting power. If all the voltages are still correct when the pic is plugged in is the most likely fault that i wired the LCD screen incorrectly? or possibly that the pic wasnt burnt properly? I've checked all the components and their locations (all correct), so if the voltage tests proved correct does that mean that there is not a single bad joint? is there anyway to test if the pic is working with a volt meter? cheers! Quote Link to comment Share on other sites More sharing options...
dreamer Posted October 6, 2008 Report Share Posted October 6, 2008 Have you tried turning the pot meters for the lcd, cause it is possible text shows up when you turn the 2 pots. Quote Link to comment Share on other sites More sharing options...
lylehaze Posted October 7, 2008 Report Share Posted October 7, 2008 As Dreamer mentioned, check the pots for the LCD, they might just show you something good.Another test would be to connect the MBox MIDI Out to your PC MIDI in. You should get one or more small SysEx messages after the core starts up.. This is the MBox waking up and asking for a program to load.It is possible that SmashTV didn't burn your PIC before sending it out to you, but the chance is pretty small. He does a lot of these things, and he is usually right on target.Troubleshooting is half the fun. :-)LyleHaze Quote Link to comment Share on other sites More sharing options...
Swine Posted October 7, 2008 Author Report Share Posted October 7, 2008 Dreamer hit it spot on! It works!!! It seems like a should have been doing a bit more reading on this site if i over looked something liek that, i was wondering what those potentiomitors did.. but thanks so much for the help. i was with lylehaze on that one about (mike?) from smash tv, i was nearly certain that he had everything in order considering how everything was perfectly packaged ect. So its wonderful seeing that little Ready text there!but... as weird as it may sound... i feel a little cheated. Dont you think that i should have struggled a little more to get my first core to work? I havent even given any real thought as to which program to upload, i thought i would be troubleshooting for a couple months ;). now it looks like ive got to catch up on the programming reading, yikes. I'm sure ill be on here again asking for everyones help very soon but for thanks much for the friendliness and simple but very very helpful/needed advice. Quote Link to comment Share on other sites More sharing options...
lylehaze Posted October 7, 2008 Report Share Posted October 7, 2008 That is great news.. Works first time!The nice thing now is that you can change from one application to another just by sending a different SysEx file, It takes just a few seconds to change up the application.When I got as far as you are now, I think my first app was the "MIDI Benchmark", since I am on a different computer than most. I wanted to test the MIDI handlers in my computer for speed. It requires no new hardware, and like I said, it lets you test your rig.I see that TK has added an LCD benchmark too.Did you change the battery in your meter? Did the voltages look closer to normal after that?Oh, just because I want you to feel like you got the full experience: If you want to send your core to me I can screw something up and send it back. That way you can get some experience looking for problems. :DHave Fun,LyleHaze Quote Link to comment Share on other sites More sharing options...
Swine Posted October 8, 2008 Author Report Share Posted October 8, 2008 The batteries in my meter were fresh, i took it to school and measured the levels there adn they were about the same (.02 off...) but still high. i just changed the wallwart to a 9.6v and the input at j1 is exactly 9.6v. every where else it is 3.85 w/o lcd and 7.78 with lcd. The 7805 hardly gets warm now as apposed to the 5.68v where it wasnt too hot to touch, but worryingly hot. so everyone that assumed the wallwart was dodgy was right. i was shocked to see that this other one that came with my boss dr202 pumped out EXACTLY 9.6 (according to my meter). As far as sending it to you? ummm no thanks haha. even though my core doesnt do anything yet i sometimes just get up and plug it in for fun and get really excited. i show my friends that come over and they just say "who gives a shit it just says ready" haha. but they also do apprciate that it takes a bit of work and luck to do this. Either way this will not be my last mb so im sure problems will arise when i start using pcbs that are pre numbered :). Thanks for answering my question as where to go now with out me having to ask. i wanted to ask but i know there is much reading that i must/want to do. but any advice would be and is greatly appreciated. im on a mac currently but im in the process of setting up bootcamp as it seems the majority of testing ect is all on pc. i was also planning on using my keyboard midi through function as the means of hooking it up to my computer through usb, is this a bad idea? ill probably end up getting one of the midi/usb boards that TK had a thread about. once again im so excited to have gotten this with virtually no problems far and all the help has been amazing! cheers!EDIT: naturally through the first couple pages of reading i realize mios studio works on mac! woo! but i also realized my key board has no midi through ports.. bollocks. Quote Link to comment Share on other sites More sharing options...
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