RobG 1,892 Posted February 5, 2012 Share Posted February 5, 2012 Store Links:The MIDI BoosterPackThe MIDI Standalone MIDI BoosterPack KitThis is a second version of my SoundPad booster pack, but I am calling it MIDI booster pack this time because it is meant to be used as a MIDI experimenter's board.What's new?MIDI outOpto isolator can be SMDIP or SOICGot rid of all expansion headers (the new board is intended to be used with 2553 only.)Intended uses? How about this:MIDI controller (4 digital/analog inputs accessible via 6 pin header, can connect pots or switches, keep in mind that 1.3 has cap/resistor attached to it on the LP board.)MIDI arpeggiatorMIDI delay/echoMapping MIDI channels/notesJust use your imagination dacoffey 1 Quote Link to post Share on other sites
RobG 1,892 Posted March 7, 2012 Author Share Posted March 7, 2012 It's ready! Here's the assembled board (no DAC or GPIO header.) I will post some code examples later. Boards will be available for purchase in few days. bluehash 1 Quote Link to post Share on other sites
bluehash 1,581 Posted March 8, 2012 Share Posted March 8, 2012 I've never worked on MIDI, so cannot appreciate this BP enough. Can someone explain it to me like I'm five .. an application. Sorry, I'm a bit behind on this tech. I know it's a protocol for musical instruments to talk to each other, but what is it used for? Quote Link to post Share on other sites
RobG 1,892 Posted March 8, 2012 Author Share Posted March 8, 2012 Here are few example applications for this booster pack: MIDI Controller - connect photo cell/LDR or joystick to analog inputs and use it to control pitch with one axis/light stream and volume/filter with the other. MIDI Arpeggiator - receive note, repeat 3 times with different notes. Think Jean Michelle Jarre. MIDI Echo - receive note, repeat decreasing velocity MIDI Monitor - display on LCD what's going on, good for troubleshooting. MIDI Splitter - receive notes on one channel, send on two different depending on octave. Left keys can control bass, right lead. MIDI Filter - get rid of those unwanted MIDI messages. Many more elpapais 1 Quote Link to post Share on other sites
bluehash 1,581 Posted March 8, 2012 Share Posted March 8, 2012 Thanks Rog. :thumbup: Quote Link to post Share on other sites
RobG 1,892 Posted March 12, 2012 Author Share Posted March 12, 2012 Thanks Rog. :thumbup: Who's Rog? I was working on turning this booster pack into a MIDI Monitor when I realized that one more thing should be included on the board (actually two, SPI/LCD connection would be useful,) SD card. The card could be very useful for turning this booster pack into a MIDI Player. Quote Link to post Share on other sites
RobG 1,892 Posted April 6, 2012 Author Share Posted April 6, 2012 Here's the fully assembled board, with SMDIP opto and optional DAC. midipad.sch BOM MIDI Two 5-pin 180 DIN sockets OK1 or OK2 - 6N138/6N139/HCPL0700/HCPL0701 IC2 - 74LVC1G07DBV D1 - 1N4148/1N914 SMD R1 - 220 0805 R2 - 270 0805 R7 - 68 0805 R8 - 68 0805 optional DAC IC1 - MCP4822SN C1 - 10uF/6.3V B (can be 1u - 10u) C2 - 0.1uF 0805 C3 - 4n7 0805 (C3 and C4 are filter caps, so they can be anything from 1n - 10n) C4 - 4n7 0805 C5 - 2u2/10V B (C5 and C6 can be 1u - 4u7) C6 - 2u2/10V B R3 - 22k 0805 (can be larger) R4 - 22k 0805 (can be larger) R5 - 1k 0805 R6 - 1k 0805 Quote Link to post Share on other sites
Dougster 0 Posted April 19, 2012 Share Posted April 19, 2012 How do I buy one of these booster packs? Quote Link to post Share on other sites
bluehash 1,581 Posted April 21, 2012 Share Posted April 21, 2012 PCBs in Store now. Quote Link to post Share on other sites
RobG 1,892 Posted April 21, 2012 Author Share Posted April 21, 2012 Looks like I forgot to update header labels after moving wires. GND 1.4 1.3 1.0 1.6 Vcc Should be 1.4 1.3 GND 1.0 1.6 Vcc Quote Link to post Share on other sites
Sonic 2 Posted April 27, 2012 Share Posted April 27, 2012 Hi Rob I'm having difficulty getting even a simple test working with the Midi booster and I wonder if you can help. Your midi arpeggiator and harmonizer compile, load and run fine through CCS. I seem to get no signal from midi out though when I send a note to midi in. What would you suggest I check? Ideally I'd like to be able to print some debug messages via USB to a terminal emulator on the computer so I can start picking things apart. I found oPossum's nice compact printf function (link below), but I haven't succeeded in getting it to coexist with your midi code. viewtopic.php?f=10&t=1732 Apologies for the rather noobish questions. If I can get a wee bit of help, I think I can start figuring a few more things out. Thanks Richard Quote Link to post Share on other sites
RobG 1,892 Posted April 27, 2012 Author Share Posted April 27, 2012 Can you receive MIDI? First thing, make sure your RXD/TXD jumpers are removed from J3. Load the harmonizer and put a break point in midi.c at line 24 handleMIDI... #pragma vector=USCIAB0RX_VECTOR __interrupt void USCI0RX_ISR(void) { handleMIDI(UCA0RXBUF); } Send MIDI, your debug session should pause at the break point. Remove break point and put it on line 29 sendMIDI... #pragma vector=USCIAB0TX_VECTOR __interrupt void USCI0TX_ISR(void) { sendMIDI(); // done sending previous byte, see if there's anything else to send } Send MIDI, your debug session should pause at the break point. Remove break point and put a LED in MIDI OUT socket, anode to pin 4, cathode to pin 5. When sending MIDI, the LED should be blinking. Let me know the results. BTW, I have improved my arpeggiator code, but I need to test it before posting it, will do that next week. Sonic 1 Quote Link to post Share on other sites
Sonic 2 Posted April 27, 2012 Share Posted April 27, 2012 Thanks Rob I had indeed neglected to remove the TXD and RXD jumpers from J3, so I removed those. I think for a brief moment I succeeded in having it pause on the breakpoint on line 24 of midi.c. It paused immediately from the MIDI clock transmitted from my drum machine. So I disabled the clock, but then for some reason since then I haven't been able to repeat receiving any kind of MIDI. I've tried: - midi output from different sources - testing the output from each source with a usb midi interface and midi monitor software - checking the midi cables - checking the DIN socket connections for continuity - swapping in a new 2553 - creating a fresh CCS project - testing the 6N139 for a short between collector and emitter hmm :think: Quote Link to post Share on other sites
RobG 1,892 Posted April 27, 2012 Author Share Posted April 27, 2012 You have to specify MIDI channel, 0 = channel 1, 1 = channel 2, etc. char channel = 0; Drum machine would most likely be sending on channel 10. I guess you can start testing from the beginning. Connect pin 5 of the MIDI IN to ground and pin 4 to Vcc (+3.6V,) you should see ~5mA current. Connect your volt meter to P1.1 and do above, you should see changes, ~5mA. If that works, that means MIDI IN hardware is OK. To test MIDI OUT, connect your volt meter to pin 4 and GND, you should see +3.6V. Remove 2553 chip from the board. Connect your amp meter to pin 4 and 5 of MIDI OUT, then connect P1.2 to Vcc, you should see changes. If that works, MIDI OUT is OK. Sonic 1 Quote Link to post Share on other sites
Sonic 2 Posted April 27, 2012 Share Posted April 27, 2012 Ah. A good thought. But that doesn't seem to be it. Is there a simple way to check if the 430 is receiving any kind of signal at all? Quote Link to post Share on other sites
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