mbe2 JDP 2007 Gadgets Boutique Inc. 1 mbe2 Accordion/bandoneon encoder with Air-pressure control * user s guide * 1. Purpose mbe2 is a small electronic unit, designed to be incorporated in accordion-like instruments (accordion, concertina, bandoneon etc.) in order to make them capable to control synthesizers. mbe2 has two 8x8 scanmatrices, each scanning up to 64 key contacts, analog input for connecting potentiometer and on-board air-pressure transducer. The parameter controlled by Air-pressure as well as parameters controlled by potentiometer are user-programmable by means of free software utility. The event per key contact is user-programmable for each of pressure/bellows directions. The factory pre-programmed events are shown in Table 1. The programming utility SxBlast is free downloadable from our site. The unit can be powered from battery as well as from power supply adapter. 2. Wiring diagram The wiring diagrams of typical mbe2 based applications are shown in Appendices A,B and C. The mbe2 scanmatrix headers are compatible with sm8x8 and keymux64 units. For battery powered application we recommend either using of sm8x8 or direct key contacts wiring. When using keymux64 for interfacing keys, the wiring is minimal compared to other cases, but the application should be powered from external adapter as the current is three times higher in such case. Direct wiring is recommended for applications with limited space where no room for two sm8x8 is available, but requires much more wiring and diode per key. 3. Settings The events for each of mbe2 controls are user-programmable by means of free-downloadable software utility called SxBlast: - For air-pressure control: response curve, message; - For potentiometer control: message; - For each key contact on both sides: On/Off message for positive air pressure (bellows closing), On/Off message for negative air pressure (bellows opening). Once changed, the parameters are memorized in non-volatile memory and used until next change. Table 1. Programmable parameters (factory pre-programmed values) mbe2 control side channe Note message l Key 1 Right Note 36 1 Key 2 Right Note 37 1 Key 3 Right Note 38 1 Key 4 Right Note 39 1 Key 5 Right Note 40 1 Key 6 Right Note 41 1 Key 7 Right Note 42 1 Key 8 Right Note 43 1 Key 9 Right Note 44 1 Key 10 Right Note 45 1 Key 11 Right Note 46 1 On/Off messages may be different for both bellows directions
mbe2 JDP 2007 Gadgets Boutique Inc. 2 Key 12 Right Note 47 1 Key 13 Right Note 48 1 Key 14 Right Note 49 1 Key 15 Right Note 50 1 Key 16 Right Note 51 1 Key 17 Right Note 52 1 Key 18 Right Note 53 1 Key 19 Right Note 54 1 Key 20 Right Note 55 1 Key 21 Right Note 56 1 Key 22 Right Note 57 1 Key 23 Right Note 58 1 Key 24 Right Note 59 1 Key 25 Right Note 60 1 Key 26 Right Note 61 1 Key 27 Right Note 62 1 Key 28 Right Note 63 1 Key 29 Right Note 64 1 Key 30 Right Note 65 1 Key 31 Right Note 66 1 Key 32 Right Note 67 1 Key 33 Right Note 68 1 Key 34 Right Note 69 1 Key 35 Right Note 70 1 Key 36 Right Note 71 1 Key 37 Right Note 72 1 Key 38 Right Note 73 1 Key 39 Right Note 74 1 Key 40 Right Note 75 1 Key 41 Right Note 76 1 Key 42 Right Note 77 1 Key 43 Right Note 78 1 Key 44 Right Note 79 1 Key 45 Right Note 80 1 Key 46 Right Note 81 1 Key 47 Right Note 82 1 Key 48 Right Note 83 1 Key 49 Right Note 84 1 Key 50 Right Note 85 1 Key 51 Right Note 86 1 Key 52 Right Note 87 1 Key 53 Right Note 88 1 Key 54 Right Note 89 1 Key 55 Right Note 90 1 Key 56 Right Note 91 1 Key 57 Right Note 92 1 Key 58 Right Note 93 1 Key 59 Right Note 94 1 Key 60 Right Note 95 1 Key 61 Right Note 96 1 Key 62 Right Note 97 1 Key 63 Right Note 98 1 Key 64 Right Note 99 1 Key 1 Left Note 36 2 Key 2 Left Note 37 2 Key 3 Left Note 38 2 Key 4 Left Note 39 2 Key 5 Left Note 40 2 Key 6 Left Note 41 2 Key 7 Left Note 42 2 On/Off messages may be different for both bellows directions
mbe2 JDP 2007 Gadgets Boutique Inc. 3 Key 8 Left Note 43 2 Key 9 Left Note 44 2 Key 10 Left Note 45 2 Key 11 Left Note 46 2 Key 12 Left Note 47 2 Key 13 Left Note 48 2 Key 14 Left Note 49 2 Key 15 Left Note 50 2 Key 16 Left Note 51 2 Key 17 Left Note 52 2 Key 18 Left Note 53 2 Key 19 Left Note 54 2 Key 20 Left Note 55 2 Key 21 Left Note 56 2 Key 22 Left Note 57 2 Key 23 Left Note 58 2 Key 24 Left Note 59 2 Key 25 Left Note 60 2 Key 26 Left Note 61 2 Key 27 Left Note 62 2 Key 28 Left Note 63 2 Key 29 Left Note 64 2 Key 30 Left Note 65 2 Key 31 Left Note 66 2 Key 32 Left Note 67 2 Key 33 Left Note 68 2 Key 34 Left Note 69 2 Key 35 Left Note 70 2 Key 36 Left Note 71 2 Key 37 Left Note 72 2 Key 38 Left Note 73 2 Key 39 Left Note 74 2 Key 40 Left Note 75 2 Key 41 Left Note 76 2 Key 42 Left Note 77 2 Key 43 Left Note 78 2 Key 44 Left Note 79 2 Key 45 Left Note 80 2 Key 46 Left Note 81 2 Key 47 Left Note 82 2 Key 48 Left Note 83 2 Key 49 Left Note 84 2 Key 50 Left Note 85 2 Key 51 Left Note 86 2 Key 52 Left Note 87 2 Key 53 Left Note 88 2 Key 54 Left Note 89 2 Key 55 Left Note 90 2 Key 56 Left Note 91 2 Key 57 Left Note 92 2 Key 58 Left Note 93 2 Key 59 Left Note 94 2 Key 60 Left Note 95 2 Key 61 Left Note 96 2 Key 62 Left Note 97 2 Key 63 Left Note 98 2 Key 64 Left Note 99 2 Potentiometer - CC b 1 Expression Air-pressure sensor - CC 7 1 Volume
mbe2 JDP 2007 Gadgets Boutique Inc. 4 Air-pressure response curve - Linear - Can be Linear, Log, Exp, S-type Besides the programmed parameter, air-pressure sensor controls notes (re-)triggering. When certain key is held down and the bellows direction changes, the note of this key is being re-triggered. If the same note is programmed for this key per direction, the same note will be re-triggered as this happens in accordion. If different notes are programmed for this key per direction, then the proper note will be triggered upon bellows change. This behaviour is specific for bandoneon as well as some types of concertinas. The channel is programmable for each message so that user can set both sides of instrument to transmit on separate channels or set them to transmit the left side to transmit same note ranges on different MIID channels as well as different note ranges on the same channel. The key contacts on both sides are expected to be normally open. The potentiometer is expected to be 10 kohm, linear. Non-linear potentiometers of 2-20 kohm could be used either. Programming using SxBlast requires using PC-compatible computer, running SxBlast software. Following steps should be performed for this: - run SxBlast software (free downloadable from our site) and select the output port of your sound card; - connect mbe2 input to PC s sound card output using either cable or -PC adapter where necessary; - power up the mbe2 unit; - select desired event per key, potentiometer and airpressure sensor and send it clicking on SendSysEx button. Note that only one control/key can be programmed at a time. Separate programming per control makes programming process slower but allows maximal flexibility; - repeat previous step as many times as many controls you need to program; - disconnect mbe2 unit from PC and use it. Whatever is programmed in it, will be kept in mbe2 internal non-volatile memory till next change. Programming using sequencer or another third-party sequencing software using SysEx messages is also possible. The format of SysEx messages is shown in Appendix D.
mbe2 JDP 2007 Gadgets Boutique Inc. 5 4. Technical parameters. The most important technical parameters of mbe2 are listed in Table 2. Table 2. Technical parameters Parameter Value Unit Comment Power supply voltage Power supply current Max. number of scanned contacts 9-12 AC/DC 20 ma 2x64+1 Battery or AC/DC Adaptor - Normally open type Scanrate 250 S -1 being scanned 250 times Each key contact is per second messages for key contacts messages for potentiometer messages for potentiometer note range NoteOn/ NoteOff CC/Pitc h Wheel CC/Pitc h Wheel - - - full - Velocity full - User-programmable Note and Channel User-programmable Channel User-programmable Channel and Response curve Constant velocity per key as programmed by user channels 1 16 - As programmed by user Size 9 x 6.5 cm Approx. 3.5 x 2.6 Weight 48 g Approx. 1.7 oz
mbe2 JDP 2007 Gadgets Boutique Inc. 6 Appendix A. mbe2 wiring diagram (when bundled with two keymux64 key multiplexor boards)
mbe2 JDP 2007 Gadgets Boutique Inc. 7 Appendix B. mbe2 wiring diagram (when bundled with two sm8x8 spread boards)
mbe2 JDP 2007 Gadgets Boutique Inc. 8 Appendix C. mbe2 wiring diagram (direct key contact wiring, requires diode per key contact)
mbe2 JDP 2007 Gadgets Boutique Inc. 9 Appendix D. mbe2 programming by SysEx messages --------------------------------------- SysEx for programming Key events: 20 bytes --------------------------------------- F0 - start SysEx 00 - first ID 21 - sec. ID (MGB) 7F - thd. ID (MGB) 07 - Device ID (MBE2 = 07) 00 - Device sub-id (Message ID = 00: Key events programming) ee - Key number (0..63-right part, 64..127-left part) d0 - PushOn event, Status byte (bit#7 must be forced to 0!) d1 - PushOn event, Data1 byte d2 - PushOn event, Data2 byte d3 - PushOff event Status byte (bit#7 must be forced to 0!) d4 - PushOff event Data1 byte d5 - PushOff event Data2 byte d6 - PullOn event, Status byte (bit#7 must be forced to 0!) d7 - PullOn event, Data1 byte d8 - PullOn event Data2 byte d9 - PullOff event Status byte (bit#7 must be forced to 0!) d10 - PullOff event Data1 byte d11 - PullOff event Data2 byte F7 - SysEx end --------------------------------------- SysEx for programming Settings: 20 bytes --------------------------------------- F0 - start SysEx 00 - first ID 21 - sec. ID (MGB) 7F - thd. ID (MGB) 07 - Device ID (MBE2 = 07) 01 - Device sub-id (Message ID = 01: Air/Pot events programming) ee - unused (always 127) d0 - Air event, Status byte (bit#7 must be forced to 0!) d1 - Air event, Data1 byte d2 - unused (always 127) d3 - Pot event Status byte (bit#7 must be forced to 0!) d4 - Pot event Data1 byte d5 - unused (always 127) d6 - Pressure response curve No (0-3) d7 - unused (always 127) d8 - unused (always 127) d9 - unused (always 127) d10 - unused (always 127) d11 - unused (always 127) F7 - SysEx end