This page will introduce the serial tool. You will learn how to connect Khadas SBC to PC and install debugging software on different PCs.
Take a serial tool, which is also known as an USB to TTL Converter like CH340 USB to TTL Converter.
You can connect your serial tool to the board GPIO pins, referring to the following diagram,
Serial tools pin | GPIO board header pin | Name |
---|---|---|
GND | 17 | |
TXD | 18 | Linux_Rx |
RXD | 19 | Linux_Tx |
VCC(3.3V) | 20 |
Insert the USB port into your computer.
TXD
RXD
GND
Use the minicom
serial communication program.
1. Install
$ sudo apt update $ sudo apt install minicom
Add permissions to access
$ sudo usermod -a -G dialout $(whoami)
You may need to logout or reboot your system to take effect.
2. Setup
Connect your SBC to the computer via the USB to TTL Converter tool before setting up minicom
.
$ sudo minicom -s
Enter the minicom
setup mode:
+-----[configuration]------+ | Filenames and paths | | File transfer protocols | | Serial port setup | | Modem and dialing | | Screen and keyboard | | Save setup as dfl | | Save setup as.. | | Exit | | Exit from Minicom | +--------------------------+
Use the up/down arrow keys to shift to Serial port setup
, and hit Enter to enter the Serial port setup menu
.
Shift
+ A
to setup the serial device, hit Enter to confirm.Shift
+ E
to setup the baudrate, choose 115200
and hit Enter to confirm.Shift
+ F
to disable the hardware flow control, set to NO
.After completing the setup, hit Enter to exit, then choose Save setup as dfl, then Exit from Minicom.
The serial device node must correspond to Ubuntu’s serial device node.
3. Launch
Type minicom
into the Ubuntu Terminal:
$ minicom elcome to minicom 2.7.1 OPTIONS: I18n Compiled on Dec 23 2019, 02:06:26. Port /dev/ttyUSB0, 15:24:13 Press CTRL-A Z for help on special keys Ubuntu 20.04.2 LTS Khadas ttyS0 Khadas login:
4. Exit
You can use Ctrl
+A
+Z
to open the menu:
+-------------------------------------------------------------------+ | 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. | +-------------------------------------------------------------------+
Use Shift
+Q
to exit minicom
.
+----------------------+ | Leave without reset? | | Yes No | +----------------------+
Choose Yes
and hit Enter to exit minicom
.
sudo minicom
./dev/ttyUSB0: Permission denied
space
or control-c
to stop auto-boot. You will see the prompt kvim#
when you've entered U-boot.1. Install Driver
Install the CH340 driver.
2. Install SecureCRT
Download the program from the SecureCRT website.
3. Setup SecureCRT
Before starting SecureCRT, you’ll need to connect the USB to TTL Converter tool to your SBC and computer.
Launch SecureCRT and navigate to File
→Quick Connect
:
Select the Serial
protocol, select the correct device node, set the baudrate to 115200
, unselect XON/XOFF
.
Click Connect
.
1. Setup Meta key
minicom needs a Meta key. Use Terminal to create a Meta key.
Go to Terminal
→Preferences
→Keyboard
, select Use Option as Meta key.
2. Install
$ sudo apt update $ sudo apt install minicom
Add access permissions
$ sudo usermod -a -G dialout $(whoami)
You may need to logout or reboot your system for changes to take effect.
3. Setup
Connect the USB to TTL Converter tool to your SBC and computer before setting up minicom
.
$ sudo minicom -s
Enter the minicom setup mode:
+-----[configuration]------+ | Filenames and paths | | File transfer protocols | | Serial port setup | | Modem and dialing | | Screen and keyboard | | Save setup as dfl | | Save setup as.. | | Exit | | Exit from Minicom | +--------------------------+
Use the up/down arrows to shift to Serial port setup
, and hit Enter to enter the Serial port setup menu
.
Shift
+ A
to setup the serial device, hit Enter to confirm.Shift
+ E
to setup the baudrate, choose 115200
and hit Enter to confirm.Shift
+ F
to disable the hardware flow control, set to NO
.After completing the setup, hit Enter to exit, then choose Save setup as dfl, then Exit from Minicom.
The serial device node must correspond to the Mac OS’ serial device node.
4. Launch
Type minicom
into the Ubuntu Terminal:
$ minicom elcome to minicom 2.7.1 OPTIONS: I18n Compiled on Dec 23 2019, 02:06:26. Port /dev/ttyUSB0, 15:24:13 Press CTRL-A Z for help on special keys Ubuntu 20.04.2 LTS Khadas ttyS0 Khadas login:
5. Exit
You can use Ctrl
+A
+Z
to open the menu:
+-------------------------------------------------------------------+ | 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. | +-------------------------------------------------------------------+
Use Shift
+Q
to exit minicom
.
+----------------------+ | Leave without reset? | | Yes No | +----------------------+
Choose Yes
and hit Enter to exit minicom
.