Noob Just built a Core V3, but no response from Core - SOLVED !

Testing/Troubleshooting
1

Hi to all,

i just finished building a Core V3, which i would like to use for a little MIDI filter/processor application.

I took the reasonable time for soldering, and then, before inserting the PIC18F452 (that i bought at Mike’s Midishop, asking it with bootloader) and the 7805, i made the voltage test beetween the pin couples, and gave me the 5V required on each couple (i have no LCD yet, that i just ordered on ebay,  and so i powered it up using a 9V battery).

I was thrilled, and then putted in place the PIC and the 7805.

I then built the MIDI IN and OUT cables (the kit came with outboard midi connectors), setted up MIOS Studio (but also MIDIOX, configuring the MIDI ports correctly, i think). But i get no response from the Core (and i’ve read that at least a sysex string, upload request, should have been received…).

I’m a total electronics noob, and i really don’t understand what’s happening; my solderings seem to be fine. I don’t know it my PIC came with MIOS installed (does Mike’s PIC come that way ?).

The only thing i can do is to provide here the values i read over the PIC pins and over the MIDI (J12 and J13) connections:

PIC18F452 (Looking with j8/j9 at bottom)

right side pins

pin 26 (RC7) +5V

pin 28 (RD5) +5V

pin 29 (RD6) +5V

pin 31 (Vss) +0.60V

pin 32 (VDD) +5V

pin 37 (RB4) +5V

left side pins

pin 01 (MCRL) +5V

pin 02 (RA0) +5V

pin 06 (RA4) +5V

pin 11 (Vdd) +5V

pin 12 (Vss) +0.60V

pin 13 (OSC1) +1V

pin 14 (OSC2) +2.2V

pin 18 (RC3) +5V

pin 20 (RD1) +5V

All other pins: +0.30V

J12/MIDIOUT

pin 01: +5V

pin 02: +0.60V

pin 03: +0.30V

J13/MIDIIN

all at 0.00V

I’ve also tried to attach a led to J12 (i’ve read that it should flash, attaching + on pin 1 of J12 and - to pin 3 of J12); instead, the led remains permanently on..

Sorry for my lack of terminology, i’ve tried to read posts describing similar problems, but i really didn’t understand them..

Can someone help me ? Also, how do i know if my PIC has bootstrap loaded ?

Thanks very much in advance

.

2

Perhaps you missed this post: HEY YOU! YES, YOU! READ THE STICKY THREADS!!!  :wink:

Firstly: without the 7805, you should have not gotten 5V. The 5V comes from the 7805 (that’s what the “05” stands for). Something doesn’t make sense there. You should double-check your work.

Next up: What does the LCD say during all of this?

After that, if you believe tho core is running, you should go to ucapps.de and follow the MIDI troubleshooting doc. Paste the results of all the tests here, and we’ll see how we go.

3

That’s what i’m a noob for :slight_smile:

I’m sorry, i talked about the 7805, but i really intended the IC2 6N138 (from the Core page on ucapps):

Apply power to the module after all parts except the PIC and the optocoupler are mounted. Check the voltage levels between the most important pins with a multimeter (analog or digital doesn’t matter) before plugging the PIC and the 6N138 into the socket:

IC1:MCLR(1) - IC1:Vss(12) = 5V

IC1:Vdd(11) - IC1:Vss(12) = 5V

IC1:Vdd(32) - IC1:Vss(31) = 5V

IC2(8) - IC2:(5) = 5V

As i said before, i have no LCD yet; but i think the core could be tested even without it, isn’t it right ?

I took the MIDI troubleshooting, apart from TEST PROG1: how do i use the verify function P18 ?

TEST CORE1: i though the crystal was right… but on its top, looking better for this troubleshooting, i read 10.000Mhz, instead of 10Mhz… is this correct ? it looks anyway very similar to the one in the Core picture (a silver square ellipse) on ucapps…;

TEST CORE2: not applicable (Core V3);

TEST CORE3: solderings seem good, and no visible missed junctions;

TEST CORE4:

   PIC:   pin 11, 20, 32, 26 are +5V, pin 25 (“5V when nothing is sent”) is +0.30V.

   6N138: Pin 8 is +5V.

   MIDIOUT: pin1 of J12 is +5V.

   Checked against power supply + as shown.

TEST CORE5:

   after C2: +6.50V (variable, however more than 6V)

   PIC pin 12: +6.50V

   PIC pin 31: +6.40V

   J3 pin: not applicable

   6N138 pin 5: +6.40V

   7805 pin 2: +6.40V

   Checked against power supply - as shown.

 

TEST CORE6:

   polarity is correct for midi plugs

TEST CORE7:

   polarity is correct for D1 protection diode

TEST CORE8:

   both R7 and R8= 220ohm

TEST CORE9:

 

   crosslink correct (Core MIDI OUT to pc MIDI IN, PC MIDI OUT to Core MIDI IN)

 

TEST CORE10:

   not applicable, no message

TEST CORE11:

   C5 is connected properly

TEST OUT1:

   Led does not flicker

TEST OUT2:

   Tried to disconnect middle pin of J12, nothing changes

Thanks once again

4

UPDATE !! I hook the Core to a power supply, instead of the battery (maybe too weak ?), and all works as expected !

I’ve then uploaded MIOS and the application (that i wrote before and was ready for a while, using the fantastic GUISIM!) and it’s all working perfect.

Sorry for the time lost on a non problem.

THANKS, have a nice time

5

THANKS, have a nice time

LOL

6

Sorry for the time lost on a non problem.

Not at all. If you want to run it off a battery, you wight like to have a quick search around the forum, as it has been discussed before. Things like low-drop regulators and such can be helpful mods. Much easier to use mains if you can, though!