Raspberry Pi 5の設定
前に戻る
- Getting Started
- Audio
- Board
- Board公式サイト
- I2S設定
- sudo nano /boot/firmware/config.txt
- dtparam=i2s=on の # を取って enable に
- dtoverlay=allo-boss-dac-pcm512x-audio を追記
- VNCの設定
- UARTをMIDIにする設定
- 5pinDIN MIDIボードの販売ページ
- Raspberry Pi の UART 速度の調整
- Raspberry Pi GPIOを使用したシリアル通信
- GPIO で UART を使う
- Need to update UART documentation for Pi5
- For example, on Pi4 with bullseye, specifying
console=serial0,115200 in cmdline.txt when uart_enable=1 and/or dtoverlay=disable-bt is asserted in config.txt results in serial0 being linked as primary (i.e. ttyAMA0) and the console being enabled on pins 14/15 on J8 enabling firmware boot and kernel messages on boot and the system console via the J8 pins. In terms of aliases we have /dev/serial0 -> ttyAMA0 and /dev/serial1 -> ttyS0. All good.
Not so on Pi5.
Instead on Pi5 with bookworm this configuration seems to enable all this on new UART connector. A different setup is needed to replicate backward compatible behaviour which setup seems to be: specify console=ttyAMA0,115200 in cmdline.txt when dtparam=uart0=on is asserted in config.txt. All good, but confusing as now /dev/serial0 -> ttyAMA10 where (I’m guessing ttyAMA10 is the new port) and /dev/serial1 is not assigned at all? If we also assert dtoverlay=disable-bt in config.txt we get aliases /dev/serial0 -> ttyAMA10 and /dev/serial1 -> ttyS0.
- serial0 is meant to be an alias for the “main” UART. On all Pis before Pi 5 this is obviously the UART enabled on GPIOs 14 & 15 (pins 8 & 10). This is the UART that a serial console would be enabled on (if wanted) by the
console=serial0,115200 in cmdline.txt. Pi 5 changes this by making the UART on the 3-pin debug header the default for serial0 - /dev/ttyAMA10. You can override this behaviour with dtparam=uart0_console, which enables UART0 and makes serial0 an alias for it.
- serial1 is an alias for the UART used for Bluetooth, which is not accessible on the 40-pin header. However, on Bookworm (more accurately, since the newer 6.1 kernels) the kernel configures the UART for Bluetooth in a way that it has no
/dev/tty... entry. As a result there is no /dev/serial1. N.B. It is still possible to revert to the old behaviour using dtparam=krnbt=off, but this isn’t guaranteed to work forever.
- 掲示板でRpi5×UART×MIDIの話
- 公式のマニュアル
- で、結局どうなったかというと、
- sudo raspi-config で、Interface Options -> Serial Port -> No -> Yes
- /boot/firmware/config.txt に以下を書く
enable_uart=1
init_uart_baud=38400
dtoverlay=midi-uart0-pi5
dtoverlay=disable-bt
dtparam=uart0=on
- この状態で、serial0, serial1 両方とも使えず、プログラムからは
/dev/ttyAMA0 でアクセスする