Firefly-RK3399

作为Firefly新一代的顶级开源平台,Firefly-RK3399采用了六核64位“服务器级”处理器Rockchip RK3399,拥有2GB/4GB DDR3和16G/32GB eMMC, 并新增DP 1.2、PCIe 2.1 M.2、Type-C、USB3.0 HOST等高性能数据传输和显示接口。Firefly-RK3399强大的性能配置将给VR、全景拍摄、视觉识别、服务器、3D等前沿技术带来里程碑的变革。

串口调试

更新时间:2018-02-08 阅读:14091

选购适配器

网店上有许多USB转串口的适配器,按芯片来分,有以下几种:

  1. PL2303

  2. CH340

  3. CP210X

注意:RK3399默认的波特率是1500000,有些USB转串口芯片波特率无法达到1500000,同一芯片的不同系列也可能会有差异,所以在选购之前一定要确认是否支持。

硬件连接

串口转 USB 适配器,有四根不同颜色的连接线:

  • 红色:3.3V 电源,不需要连接

  • 黑色:GND,串口的地线,接开发板串口的 GND 针

  • 白色:TXD,串口的输出线,接开发板串口的 TX 针

  • 绿色:RXD,串口的输入线,接开发板串口的 RX 针

具体如下图:

串口连接

连接参数

Firefly-RK3399 使用以下串口参数:

  • 波特率:1500000

  • 数据位:8

  • 停止位:1

  • 奇偶校验:无

  • 流控:无

Windows 上使用串口调试

安装驱动

下载驱动并安装:

如果在 Win8 上不能正常使用 PL2303,参考这篇文章, 采用 3.3.5.122 或更老版本的旧驱动即可。

插入适配器后,系统会提示发现新硬件,并初始化,之后可以在设备管理器找到对应的 COM 口:

设备管理器

安装软件

Windows 上一般用 putty 或 SecureCRT。其中 putty 是开源软件,在这里介绍一下,SecureCRT 的使用方法与之类似。

到这里 [4] 下载 putty,建议下载 putty.zip,它包含了其它有用的工具。

解压后运行 PUTTY.exe,选择 Connection type(连接类型)为 Serial(串口),将 Serial line(串口线)设置成设备管理器所看到的  COM 口,并将 Speed(波特率)设置为 1500000,按 Open(打开)即可:

putty

Ubuntu 上使用串口调试

在 Ubuntu 上测试过可以支持1500000波特率的串口调试工具有:

  • minicom

以下就介绍 minicom的使用。

安装:

sudo apt-get install minicom

连接好串口线的,看一下串口设备文件是什么,下面示例是 /dev/ttyUSB0

$ ls /dev/ttyUSB*
/dev/ttyUSB0

运行:

$ sudo minicom
Welcome to minicom 2.7                                                                                                 
                                                                                                                       
OPTIONS: I18n                                                                                                          
Compiled on Jan  1 2014, 17:13:19.                                                                                     
Port /dev/ttyUSB0, 15:57:00                                                                                            
                                                                                                                       
Press CTRL-A Z for help on special keys

以上提示 CTRL-A Z 是转义键,按 Ctrl-a 然后再按 Z 就可以调出帮助菜单。

                                                 +-------------------------------------------------------------------+
                                                 |                      Minicom Command Summary                      |
                                                 |                                                                   |
                                                 |              Commands can be called by CTRL-A <key>               |
                                                 |                                                                   |
                                                 |               Main Functions                  Other Functions     |
                                                 |                                                                   |
                                                 | Dialing directory..D  run script (Go)....G | Clear Screen.......C |
                                                 | Send files.........S  Receive files......R | cOnfigure Minicom..O |
                                                 | comm Parameters....P  Add linefeed.......A | Suspend minicom....J |
                                                 | Capture on/off.....L  Hangup.............H | eXit and reset.....X |
                                                 | send break.........F  initialize Modem...M | Quit with no reset.Q |
                                                 | Terminal settings..T  run Kermit.........K | Cursor key mode....I |
                                                 | lineWrap on/off....W  local Echo on/off..E | Help screen........Z |
                                                 | Paste file.........Y  Timestamp toggle...N | scroll Back........B |
                                                 | Add Carriage Ret...U                                              |
                                                 |                                                                   |
                                                 |             Select function or press Enter for none.              |
                                                 +-------------------------------------------------------------------+

根据提示按O进入设置界面,如下:

           +-----[configuration]------+                                                                               
           | Filenames and paths      |                                                                               
           | File transfer protocols  |                                                                               
           | Serial port setup        |                                                                               
           | Modem and dialing        |                                                                               
           | Screen and keyboard      |                                                                               
           | Save setup as dfl        |                                                                               
           | Save setup as..          |                                                                               
           | Exit                     |                                                                               
           +--------------------------+

把光标移动到“Serial port setup”,按enter进入串口设置界面,再输入前面提示的字母,选择对应的选项,设置成如下:

   +-----------------------------------------------------------------------+                                          
   | A -    Serial Device      : /dev/ttyUSB0                              |                                          
   | B - Lockfile Location     : /var/lock                                 |                                          
   | C -   Callin Program      :                                           |                                          
   | D -  Callout Program      :                                           |                                          
   | E -    Bps/Par/Bits       : 1500000 8N1                               |                                          
   | F - Hardware Flow Control : No                                        |                                          
   | G - Software Flow Control : No                                        |                                          
   |                                                                       |                                          
   |    Change which setting?                                              |                                          
   +-----------------------------------------------------------------------+

注意:Hardware Flow Control和Software Flow Control都要设成No,否则可能导致无法输入。
设置完成后回到上一菜单,选择“Save setup as dfl”即可保存为默认配置,以后将默认使用该配置。