TK. Posted December 22, 2010 Report Share Posted December 22, 2010 In the last days I worked on a major MBHP_MF update, mainly triggered by Screaming Rabbit who gave me a big package of different Alps faders for free! :) Design Targets: find a solution to handle high-quality faders like Alps K faders with "coreless" motorsfind a solution for MBHP_CORE_LPC17 which doesn't deliver stable enough ADC conversion results due to the reduced 3.3V voltage rangefind a solution for MBHP_CORE_LPC17 which cannot handle touch sensors properly without heavy CPU load (resp. without an additional external device or microcontroller)find a solution which is compatible with PIC based projects for best usabilityfind a solution which is DIY friendly and doesn't require additional gear (e.g. chip programmer) for something which isn't part of the MBHP yetfind a solution which can be easily tested and troubleshooted (no need to learn new processes) Following circuit is the result: http://www.ucapps.de/mbhp/mbhp_mf_ng.pdfa dedicated PIC controller controls the motorfaders directlyit can be accessed via MIDI (only) - this allows standalone usage, cascading (to chain multiple modules), and the re-use of existing infrastructure such as MIOS, MIOS Studio and MIOS Bootloaderthe module can either be connected to a PC directly, or controlled from a second PIC or STM32 or LPC17 (note that MBHP_CORE_LPC17 has a third and even a fourth MIDI IO port at TTL level so that the available two MIDI IO pairs are still free)native support of various protocols (e.g. PitchBender, CCs, even Logic Control and Mackie Control Emulation)support for 8 touch sensorsinstead of TC4427 I'm using L293D now - not at least because of the integrated diodes.due to the direct motor control connections, the PIC is now able to generate PWM with 50 uS steps for improved motor speed control while a motor is movedsince the firmware is dedicated for this task, there was enough memory free to integrate advanced features, such as runtime-calibration and motor position tracing Two snapshots of the prototype - currently I've only tested the circuit with high-quality K Faders, which were not properly controllable with MBHP_MF_V1 Meanwhile PCBs are available (layout created by SmashTV - thank you!!! :) ) MIOS Studio got a new configuration tool: Especially the calibration is much easier now, not at least because of the new motor position tracing feature: Currently following modes are planned: [*] PitchBender Chn#1..#8 [*] PitchBender Chn#9..#16 [*] CC#07 Chn#1..#8 [*] CC#07 Chn#9..#16 [*] CC#16..#23 Chn#1 [*] CC#24..#31 Chn#1 [*] Faked Logic Control [*] Faked Logic Control Extension [*] Faked Mackie Control [*] Faked Mackie Control Extension There is no real need to add more modes, considered that MIDI events can be mapped on the host PC and/or from another microcontroller (like Core32) which uses MBHP_MF_V3 as a companion. By using Pitchbender events, the highest resolution (10bit) is available. More about this topic (e.g. test of different motorfaders) after holidays. :) Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
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