failed attempt at a CORE

[jwrigh10]

I am not the one who originally made this post, but I am in the same situation. I have now built 2 cores. Admittedly, I rushed the first core, but on the second core I took my time. I inspected with a magnifying glass every solder joint. I double checked to make sure I was building the core right, but alas no success.

Using a 7.5 wall amp with 500mA I check the core. I put the black lead on the metal tab of the 7805 voltage regulator and with the red leed I check voltages on J2, and the Vdd's of the PIC. All registered 7.5-7.9 volts instead of 5 volts. In addition, when I hooked up my LCD all I get is the backlight and no data. Any suggestions would be helpful. I am very frustrated.

JW

[stryd_one]

Hi jwrigh10, welcome aboard :)

I hope that you don't mind that I have split your post off from the original so that we can pay attention to your specific issues with this PCB.

Firstly, it is wise that you checked the voltages, but I probably would avoid seating any components such as the PIC or LCD when you know that your voltages are so high.

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

Assuming that your 'wallwart' is putting out 7.5V like it is supposed to (I assume that, you should check!) from what you described, it sounds like maybe the 7805 is not doing it's job, maybe it's fried.... but even the rectifier should drop the voltage a little... It does sound like there could be a short.

I assume you have run these two tests from http://www.ucapps.de/howto_debug_midi.html :

mbhp_core_extract_measuring_gnd.gif

mbhp_core_extract_measuring_vdd.gif

Check those out and let us know....

[jwrigh10]

Thank you for your help! I quickly realized that I had installed the 7805 wrong. Stupid me. I removed it and replaced it with a new one. The voltage checks were 4.98. I plugged in the PIC and 6N138 and ran midiox. I got the appropriate screen which indicates to me it is working!! I did get an aborant reading on the vdd measurments on PIC tx which read .7v rather than the 4.98. It was the only one. I couldn't find a J3 for the ground measurments. However, with the correct message coming over Midiox I assume these are moot points or am I wrong?

I did hook up my LCD and got nothing except the backlight. Should I proceede since I recieved the correct input from midiox? I had to redo my LCD cable a couple of times and it is possible I still don't have it right.

JW

[midiboxxer]

Have you uploaded Mios?

If your answer is yes, check the contrast pot at the coremodul.

Greetings

[jwrigh10]

No, I haven't uploaded Mios. I thought that was already done. How do I upload the Mios?

JW

[Durisian]

If you bought the PIC from smashtv it will already be uploaded.

(and will say it on the chip).

If not, you need to burn bootloader with PIC burner first.

There's a link on ucapps somewhere for instructions....

[stryd_one]

How do I upload the Mios?

Translation: I need to read the wiki and come back later ;D

[midiboxxer]

http://www.ucapps.de/mios_bootstrap.html

[jwrigh10]

I figured I would get send back to the wiki for my comment "How do I upload the mios";however, I did buy the PIC from SmashTV and it is uploaded with Mios v. 1.9e. I will see if the pot adjustments on the core module are the problem.

[jwrigh10]

Pot adjustments on core were problem with LCD. However, I cannot get the DIN to work. Do I need to upload anything else?

[DavidBanner]

you'll need to upload an application into MIOS if you haven't already....

[midiboxxer]

Hi also this side on the wiki for a better understandig.

http://www.midibox.org/dokuwiki/mios

Greetings

Markus

[jwrigh10]

I must be missing something. The PIC already has MIOS on it b/c I bought it from SmashTV. Therefore, I assumed that what I have to do next is dowload the midio128 project. Correct? I downloaded the file "mk_midio128_syx."   Nxxt, I opened Midiox and set up the Midi devices. (see pic below) Then I followed the rest of the instructions per "http://www.ucapps.de/howto_tools_mbsyx.html." The only exception was changing the settings in the '"ini" and the use of pearl.  I don't know enough about what I am doing to change anything!  (You can tell I am getting frustrated :(

Anyway, loaded the following files into the Sysex: "Midio128" and "relay" for the pic18f. My midi interface and the midiox indicated that things were transfering. However, nothing has changed on my lcd reading. My DIN still does not work. I restarted the core, but nothing is different. What am I doing wrong? Sorry to be such a bother.

[midiboxxer]

The mk_midio128_syx is only a configuration dump for thze application. You have to upload this application:

http://www.ucapps.de/mios/midio128_v2_1d.zip

You should also download MIOS Studio to upload the application. The following link discribes how to do that. (Discription starts at the half of the page)

http://www.ucapps.de/mios_bootstrap_newbies.html

greetings

Markus

[jwrigh10]

I unzipped the http://www.ucapps.de/mios/midio128_v2_1d.zip, opened Midiox, followed the instructions and uploaded the file marked "main." Everything seemed to work and I recieved readings in both the Monitor Input and Output windows. In addition, I have uploaded the SysEx files from "mk_midio128_syx." I also uploaded the "main.hex" file from midio128_v2_1d.zip in Mios Studio

My LCD reads: OKOS "V3.; g"""""3+Novg" C_2""" I know that this is not right. Is it possible that I have really messed this thing up?

JW

[ris8_allo_zen0]

My LCD reads: OKOS "V3.; g"""""3+Novg" C_2""" I know that this is not right. Is it possible that I have really messed this thing up?

Have a check somewhere between D0 and D1 pins/wires of J15. If I'm not wrong "OKOS" stands for "MIOS" with the second bit always set ;)

Best regards, Enrico

[stryd_one]

If I'm not wrong "OKOS" stands for "MIOS" with the second bit always set ;)

LOL we are such geeks mate.... I thought the same thing.

I'm actually a little weirded out by that. I didn't even stop and think about it... I wonder if the pattern of characters gave us a subconcious hint?

[ris8_allo_zen0]

LOL we are such geeks mate.... I thought the same thing.

I'm actually a little weirded out by that. I didn't even stop and think about it... I wonder if the pattern of characters gave us a subconcious hint?

I don't know! But I'm sure I saw a similar pattern once on my LCDs when I was driving crazy building the cable: I crimped the wires manually one by one and there were plenty of shorts & cuts... Terrible.

But a geek is a geek :D