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Chapter 9. Hardware |  |
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Chapter 9. Hardware | |
There is a setting in sudo raspi-config that connects the serial interface to the login shell.
Connect a second Linux computer having a USB to serial 3V3 cable and appearing as /dev/ttyUSB0 then type screen /dev/ttyUSB0 115200
pin 6 is ground
pin 8 is TXD GPIO14 (connect it to RXD of the device to be attached)
pin 10 RXD GPIO15 (connect it to TDX of the device to be attached)
If it is desired to use a regular application for it, use sudo raspi-config to disable the console on the serial interface but enable to use the serial interface and sudo reboot
There are two UARTs Mini-UART (ttyS0) and PL011 UART (ttyAMA0). Since the serial interfaces is usually not used the better UART PL011 is used for the bluetooth module. However this can be reconfigured, therefore use /dev/serial0 since it is a link to the UART used for the serial interface. ls -la /dev/serial0 will show which UART is used.
The Mini-UART has a side effect of not having a stable frequency under heavy CPU load, this might cause communication problems on the serial interface. To have a stable serail interface those UARTs can be switched by adding to /boot/firmware/config.txt
dtoverlay=miniuart-bt
Now do on the Raspberry sudo screen /dev/serial0 115200 and both computers can exchange data via the serial interface.
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I2C |
