3.x vs 4.x 4.1 4.1 pads unlabeled 7.84 44.1 khz 44.117khz 1280 x 400 adc audio audioconnection audio lib oscillator audio noise guitar azeron bldc controller cli cn0391 teensy3.6 spi current dma encoder ethernet footprint frank b host port i2c touchscreen keyboard max7219 7-segment midi midi out nrf24l01 oled i2c teensy4 pcm1808 pdb pedal pins power psram radio rfi schematic sd card serial serial port sgtl5000 smart matrix shield solved spi spi seperate synthesizer synth matrix midi t4.1 teensy teensy3.2 teensy 3.6 gpio ports teensy 3.6 usb host teensy4 dma spi teensy 4.0 teensy 4.0 ili9341 ra8875 teensy 4.1 teensy 4.x teensyduino teensy emulator midi vga teensy rtc thinpot timelib time syncing timing touchscreenusb x y usbhost_t36 webserver web server hangs windows10iot