ROCKPRO64 Serial Port Pins

[xwang2019]

I have a ROCKPro64 v2.1 board and installed with "bionic-minimal-rockpro64-0.8.0rc6-1111-armhf.img". The system boots up is fine, but both /dev/ttyS0 and /dev/ttyS2 are not working. I don't know which pins out of a total 40 pins of Pi-2 are for UART 0 (/dev/ttyS0). Am I correct that Pin 8 is /dev/ttyS2 Tx Pin and Pin 10 is /dev/ttyS2 Rx Pin? Are these UART pins are enabled by default after system boot up? Should I do something to enable these pins in order for UART (/dev/ttyS0 or /dev/ttyS2) to work?

For a UART to work, I mean this ttyS0 or ttyS2 port is able to send out or receive characters. Currently, I am able to open and set up serial port but not able to send out or receive characters correctly. I guess those UART pins are shared with GPIO pins or multiplexed with GPIO functionality, some configurations may need to be done. Could you help me?

[FrankM]

Hello @xwang2019 ,

please read this post -> https://forum.frank-mankel.org/topic/53/serielle-konsole-uart2 (german)

• Nr. 6 GND - schwarz
• Nr. 8 UART2_TX - weiß
• Nr. 10 UART2_ RX - grün

With my adapter i must removed pin no. 10. With this connection i can't boot properly.

This uart connection is enabled by default in all images from ayufan.

I hope this will help you. And excuse my english isn't the best

[xwang2019]

Hi FrankM,

Thank you very much for your help. The objective of my task is to find a UART serial port (ttyS0 or ttyS2) to substitute ttyUSB0 port on ROCKPro64. I found out yesterday by reading through the schematics of ROCKPro64 v2.1 that UART0 (ttyS0) and UART2 (ttyS2) are NOT a general RS232 serial port on ROCKPro64. UART0 (ttyS0) is now connected with the Bluetooth device on ROCKPro64. UART2 (ttyS2) is now connected to Debug Port and used as a console serial port. I need to disconnect UART0 with Bluetooth device to get ttyS0 back.

Xiaoming

[FrankM]

I think i understood

You can use an image before 0.7.13

0.7.13: Enable support for RockPro64 WiFi/BT module,

Is that an option for you?

Or you edit the dts file with

sudo dtedit

Remove all entries for uart0 and copy entries from image before 0.7.13

Last but not least, ask ayufan

[xwang2019]

Hi FrankM,

Thank you very much for your help. I tried 0.7.9 image. ttyS0 doesn't work even when WiFI/BT module is disabled. Because I don't need WiFi/BT option, I am going to edit the dts file. Could you let me to know the following steps after dts file got modified? Thanks.

Regards,

Xiaoming