hi there,
i have used the usb-host feature of teensy 3.6 extensively over the last year for a midi controller project. i had all my synths connected to a usb hub and the teensy midi controller would send midi to them. in recent versions of the library i have encountered a lot of hanging notes and my whole program would crash. i rewrote my midi project now to use the standard midi usb output and will connect my (usb) synths and the controller i built to a HUB and control that via a separate teensy 4.1. one of the problems that arose with newer versions of the usbhost library seems to be that writing to unused ports causes hiccups. this was certainly no problem with the 0.1. version of the usbhost library. should this work? or is writing to non connected HUB ports a nogo? from looking at the 16x16 host midi example at least reading from (potentially) unused ports is ok.
i had a look at the new usbhost midi code and there are quite some substantial changes with regards to sending messages (timers to try and fill midi USB messages, while retaining low latency etc.) maybe there is some regression there? there are also quite a few recent forum comments about usbhost MIDI code not running smoothly (jittery midi clock for example). how were the new sending "features" tested?
additionally the 16x16 host example does not compile on Arduino 2.0.3 for teensy if i use the BigBuffer MIDIDevice, which i need to read/write from/to newer usb2 teensies. here is the error:
thanks
i have used the usb-host feature of teensy 3.6 extensively over the last year for a midi controller project. i had all my synths connected to a usb hub and the teensy midi controller would send midi to them. in recent versions of the library i have encountered a lot of hanging notes and my whole program would crash. i rewrote my midi project now to use the standard midi usb output and will connect my (usb) synths and the controller i built to a HUB and control that via a separate teensy 4.1. one of the problems that arose with newer versions of the usbhost library seems to be that writing to unused ports causes hiccups. this was certainly no problem with the 0.1. version of the usbhost library. should this work? or is writing to non connected HUB ports a nogo? from looking at the 16x16 host midi example at least reading from (potentially) unused ports is ok.
i had a look at the new usbhost midi code and there are quite some substantial changes with regards to sending messages (timers to try and fill midi USB messages, while retaining low latency etc.) maybe there is some regression there? there are also quite a few recent forum comments about usbhost MIDI code not running smoothly (jittery midi clock for example). how were the new sending "features" tested?
additionally the 16x16 host example does not compile on Arduino 2.0.3 for teensy if i use the BigBuffer MIDIDevice, which i need to read/write from/to newer usb2 teensies. here is the error:
Code:
/private/var/folders/l7/m07k7_t14kbgsj8y_sychc0c0000gn/T/arduino-sketch-B91CD7AB12FDC96842B9810B4B3F3A87/sketch/Interface_16x16.ino.cpp.o:(.rodata._ZTV20MIDIDevice_BigBuffer[_ZTV20MIDIDevice_BigBuffer]+0x10): undefined reference to `MIDIDeviceBase::timer_event(USBDriverTimer*)'
collect2: error: ld returned 1 exit status
Multiple libraries were found for "MIDI.h"
Used: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/MIDI
Not used: /Users/lokki/Documents/Arduino/libraries/MIDIarduino
Multiple libraries were found for "USBHost_t36.h"
Used: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/USBHost_t36
Not used: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/USBHost_t36_old
Using library MIDI Library at version 5.0.2 in folder: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/MIDI
Using library USBHost_t36 at version 0.2 in folder: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/USBHost_t36
Using library SdFat at version 2.1.2 in folder: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/SdFat
Using library SPI at version 1.0 in folder: /Users/lokki/Library/Arduino15/packages/teensy/hardware/avr/1.57.2/libraries/SPI
exit status 1
Compilation error: exit status 1
thanks
Last edited: