Even this minimal code was failing: on large SysEx dumps, sometimes more data was forwarded than received. Under stress conditions, received MIDI data got lost, and transmitted MIDI data was sporatically corrupted.Īfter some hours I couldn't believe anymore that this was caused by my own code, so I started to debug the transmitting issue first by writing a short program, which just forwards incoming MIDI data to the output port. During the first tests I already noticed that the example code didn't work so stable as expected. So, at a rainy weekend in March 2005 I downloaded the USB framework from the Microchip homepage, installed the USB bootloader (for quick program updates), and integrated the basic MIDI handling code into the CDC example. The USB descriptors for USB MIDI, the MIDI parser, the interrupt handlers for MIDI Rx/Tx were ready to be re-used. Initially the implementation of the firmware was planned as a nice one-day project, as I didn't expect much effort for doing a port of the Cypress based MBHP_USB to the PIC architecture, which I know pretty well. History - MBHP_USB_PIC firmware, first attempt

Just add the USB socket, a 470 nF cap, replace the crystal by a 20 MHz type, and add a Reset and Bootloader button. No PCB available (yet), but MBHP_CORE module can be used.The SysEx issue under MacOS has been fixed in V1.1 of the firmware.The latest PIC18F4550 (or PIC18F2550) revision 5 is required to overcome the EUSART bug.This means: you have to close your MIDI software (or release the MIDI ports) when using MIOS Studio Windows legacy driver is not multiclient capable.However, MIOS uploads are unidirectional, and therefore working stable enough. In general this MIDI interface works fine under Windows, MacOS and Linux, but there is a potential risk for data loss when large SysEx dumps are sent and received concurrently.This module is expired as USB is natively supported by the MBHP_CORE_LPC17 module! Summary Meanwhile a better solution has been found: MBHP_USB_GM5 It is based on the PIC18F4550 (or PIC18F2550) which is available for less than 6 US$. This module was planned as a cheap and easy alternative solution to the MBHP_USB module. MIDIbox Hardware Platform, USB PIC Module

Microchip pic serial bootloader