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It is believed that many inexperienced people are at a loss about how to use the serial port UART3 on the PX2 development board. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

UART3 is in the upper left half of this diagram (http://wiki.chipspark.com/cn/ind... 5%E5%8F%A3%E5%9B%BE). In the set of GPIO expansion interfaces, UART3 is the easiest serial port to connect to (TTL level), and it is easiest to connect peripheral devices (such as GPS, etc.) that need to connect some serial ports in the development.

PX2 does not have support for UART3 in the default Kernel configuration, which needs to be improved. A compiled version of VGA/HDMI with UART3 supported kernel is provided in the attachment for download. If you are interested, you can compile kernel. After make menuconfig in the kernel directory, click the following 4 figures to configure kernel:

After saving and exiting, make kernel.img can generate a kernel image and burn it into the board.

Kernel.img (7.89 MB, downloads: 0)

On the Android side, you can use this tool to test serial.apk (42.66 KB, download times: 1). You need root permission to access the serial port. In this tool, first Setup, select ttyS3 (that is, UART3), and enter Loopback after saving. The program will continue to send data through the TX pin of UART3. At this time, if you short connect the TX pin with the RX pin of UART3, you will see the growth of Received back data, that is, UART3 has realized the normal serial port sending and receiving.

The source code of the program is here: https://code.google.com/p/android-serialport-api/ can refer to and write its own serial control program to achieve the control of peripheral devices.

Reminder: be sure to pay attention to level matching. The UART3 of the PX2 is the TTL level, not the RS232.

After reading the above, have you mastered how to get started with the serial port UART3 on the PX2 development board? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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