smokestacksproductions Posted August 21, 2012 Report Share Posted August 21, 2012 (edited) Hello, I have made a PCB that breaks out all the I/O for 5v buffered gate triggers and additional midi ports that are found on LPC17 and CORE32 for MBSeqv4. The goal is to break out all the connections using 2x5pin IDC Headers that will connect 1:1 with the corresponding headers on the core module. The attached files are for LPC17 (which I am currently using) and they can be easily modified for core32 (swap midi I/O pins, etc.) I have integrated 5v level shifters for the 8 gates and clock start/stop etc. I have also integrated the necessary hardware for Midi I/O ports 3,and 4 (optos, resistors, etc.) I would like to make these additional midi ports operate at 5v (instead of 3.3v) to ensure compatibility with older midi devices. I'm not sure what changes are necessary to do this. As you can see there are quite a few pins free on the 74hct541 if those are required, I was wondering if I supply the "m+" pins (on the midi out ports) with 5v instead of 3.3v will this achieve the same result? If so, should the 220ohm resistor be changed to a different value? Please have a look at the eagle and quick view files I have attached. Your input is greatly appreciated! quick view .png: eagle .brd: seq expansion.rar edit: TK has provided an updated schematic of the buffered gates and midi outputs, so I will revise my PCB accordingly and repost. Edited August 21, 2012 by smokestacksproductions Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 22, 2012 Author Report Share Posted August 22, 2012 I have revised the PCB according to an updated schematic TK provided. This latest version is a bit simplified, I have eliminated MIDI I/O 4 (reserving this for the BLM connector down the road) and I have buffered the Midi 3 output to 5v with one of the free pins on the level shifting IC. See the attached .brd and quick view .brd: AOUT + MIDI IN-OUT 3.rar .png quick view: Quote Link to comment Share on other sites More sharing options...
lemonhorse Posted August 23, 2012 Report Share Posted August 23, 2012 Hello smokestacksproductions, I'm very interested in Your PCB/Project (building a SEQ V4 right now)! :) - Lemonhorse Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 23, 2012 Author Report Share Posted August 23, 2012 Hello smokestacksproductions, I'm very interested in Your PCB/Project (building a SEQ V4 right now)! :) - Lemonhorse That's great! I just ordered the components for it yesterday. I'm going to etch the pcb and assemble it over the weekend, I'll let you know how it works out on monday. In the meantime, I'm open to suggestions for how I could improve this board. Do you think it is wise to add two more ports for midi i/o 4 ? or should I just add a single port for the blm connector? I could also add midi thru ports, but they may be redundant if the MBseq has a "soft" midi thru function (I just got my seq up and running last week, so I still have a lot to learn about this amazing software. Quote Link to comment Share on other sites More sharing options...
lemonhorse Posted August 23, 2012 Report Share Posted August 23, 2012 I'll let you know how it works perfect. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted August 23, 2012 Report Share Posted August 23, 2012 (edited) Hi there, the board looks great - i´d recommend to add MIDI OUT4 and MIDI IN4 for more general purpose usage - a BLM can be connected e.g. with an external cable harness that connects to both ports... Also, methinks MIDI Thru is not necessary, as you can do all sorts of routing from within the SEQ router... Many greets, Peter Edited August 23, 2012 by Hawkeye Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 23, 2012 Author Report Share Posted August 23, 2012 OK, I will add the additional midi ports! Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 24, 2012 Author Report Share Posted August 24, 2012 OK! I have added MIDI I/O 4, here is the quick view of the new layout: Below you will find a .rar archive which contains: 1. .brd file (you may open and modify with eagle) 2. full color quick view to assist in assembly 3. negative monochrome render of bottom traces, pads, and vias (for negative photo resist process) 4. positive monochrome render of bottom traces, pads, and vias (for positive photo resist process) #4 has been optimized in photoshop to use less etchant (this is the one I will be using) I will be receiving the components for this board today. I'll let you know how it all works out after this weekend. In the meantime, if someone spots an error, or has some suggestions to make, please let me know! Here are the files: seq expansion.rar Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted August 24, 2012 Report Share Posted August 24, 2012 It looks very nice now! Thanks for your work and sharing the Eagle-files! Best of luck with etching and testing! Bye, Peter Quote Link to comment Share on other sites More sharing options...
TK. Posted August 26, 2012 Report Share Posted August 26, 2012 As already commented via PM: the MIDI connector pins are swapped in this layout. Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 26, 2012 Author Report Share Posted August 26, 2012 As already commented via PM: the MIDI connector pins are swapped in this layout. Best Regards, Thorsten. This explains why my prototype did not work! I will correct this in the .brd and re-upload. Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 27, 2012 Author Report Share Posted August 27, 2012 Here is the corrected .brd file. If someone can look at it and tell me if you can spot any other errors, I will render the positives and etc. quick view: .brd: AOUT + MIDI IN-OUT 3-4 v1.1.rar Thanks! Quote Link to comment Share on other sites More sharing options...
TK. Posted August 30, 2012 Report Share Posted August 30, 2012 should be ok now Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
MaG2k Posted September 1, 2012 Report Share Posted September 1, 2012 short question....what are the values of R3-R10 and R11-R17 + R1??? they are not in the circut! Greetingz Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted September 3, 2012 Author Report Share Posted September 3, 2012 short question....what are the values of R3-R10 and R11-R17 + R1??? they are not in the circut! Greetingz they are 220 ohm, but please allow me a bit more time before etching your own pcb,as I'm having problems with mine. Quote Link to comment Share on other sites More sharing options...
MaG2k Posted September 3, 2012 Report Share Posted September 3, 2012 okay i will wait...printed the PCB right now but good that i looked once again here on your thread... i have a question to you...is there any possibility to add the BLM-connector directly to the PCB? I red Hawkeye told something about a Y-cabel-adapter to make the BLM-connector from both additional Midi-Ports of your PCB. is there only the possibility eighter the MIDI-Ports or the BLM-connector is there a possibility to have both (two additional MIDI-Sets (MIDI IN/OUT3 and MIDI IN/OUT4) plus BLM-connector? i hope you understand my question. Regards MaG2k Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted September 4, 2012 Author Report Share Posted September 4, 2012 okay i will wait...printed the PCB right now but good that i looked once again here on your thread... i have a question to you...is there any possibility to add the BLM-connector directly to the PCB? I red Hawkeye told something about a Y-cabel-adapter to make the BLM-connector from both additional Midi-Ports of your PCB. is there only the possibility eighter the MIDI-Ports or the BLM-connector is there a possibility to have both (two additional MIDI-Sets (MIDI IN/OUT3 and MIDI IN/OUT4) plus BLM-connector? i hope you understand my question. Regards MaG2k The BLM connector occupies one set of midi in/out, so this is not possible. If you need more i/o check out the i2c midi module for up to four more midi outputs Quote Link to comment Share on other sites More sharing options...
Altitude Posted September 4, 2012 Report Share Posted September 4, 2012 (edited) Cool design, I'd make it double sided and stick a SDcard socket on the underside Edited September 4, 2012 by Altitude Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted September 5, 2012 Author Report Share Posted September 5, 2012 Cool design, I'd make it double sided and stick a SDcard socket on the underside THAT IS A GREAT IDEA! Quote Link to comment Share on other sites More sharing options...
lemonhorse Posted September 5, 2012 Report Share Posted September 5, 2012 thrilled. Quote Link to comment Share on other sites More sharing options...
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