====== Edge-2L setup serial debug console ======

===== Introduction =====

This page introduces the serial debugging tools. You will learn how to connect a Khadas SBC to a PC and install debugging software on different operating systems.

===== Preparation =====

You will need a serial tool, also known as a USB-to-TTL Converter, such as the [[https://www.amazon.com/Adaptor-Download-Adapter-Converter-LinkMore/dp/B08VGRRJ67/ref=sr_1_4?dchild=1&keywords=USB+to+TTL+ch340&qid=1629184609&sr=8-4|CH340 USB to TTL Converter]].

An [[/products/sbc/edge-2l/applications/gpio/40pin-header|Edge-2L IO board]] is required to interface with the serial tool.


===== Hardware connection =====

{{/products/sbc/edge-2l/development/edge-2l-io.webp?500|serial_connections}}

^  ^ USB-TTL pin name  ^ Edge-2L GPIO name ^ GPIO pin ^ 
| 1 | ''GND''      | ''GND'' | 4 |
| 2 | ''TXD''      | ''DRX'' | 3 |
| 3 | ''RXD''      | ''DTX'' | 2 |

Full [[/products/sbc/edge-2l/applications/gpio/40pin-header#reference-table| Edge-2L GPIO header - reference table]]
      
/* IMHO its ugly 

You can connect your serial tool to the board GPIO pins, referring to the following diagram，

  * Tool Pin ''GND'' <-> ''Pin1'' of Edge-2L IO's GPIO
  * Tool Pin ''TXD'' <-> ''Pin2'' of Edge-2L IO's GPIO ''DRX''
  * Tool Pin ''RXD'' <-> ''Pin3'' of Edge-2L IO's GPIO ''DTX''

*/

===== Setup serial communication program =====

<WRAP important >
Edge-2L Baudrate: **1500000**
</WRAP>

<tabbox Ubuntu> 

Use the ''minicom'' serial communication program.

1. **Install**

```shell
$ sudo apt update
$ sudo apt install minicom
```
Add permissions to access the serial port:
```shell
$ sudo usermod -a -G dialout $(whoami)
```
<WRAP info >
You may need to log out or reboot your system for this change to take effect.
</WRAP>

2. **Setup**

Connect your SBC to the computer via the USB-to-TTL converter before setting up ''minicom''.

```shell
$ sudo minicom -s
```

You will 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 navigate to ''Serial port setup'', and press Enter to enter the ''Serial port setup menu''.

  * Press ''A'' to set the serial device, then press Enter to confirm.
  * Press ''E'' to set the baudrate, select ''1500000'' and press Enter to confirm.
  * Press ''F'' to disable hardware flow control, and set it to ''NO''.

After completing the setup, press Enter to exit the menu, then select ''Save setup as dfl'', and finally ''Exit from Minicom''.
<WRAP info >
The serial device node must correspond to the correct serial device node in Ubuntu.
</WRAP>

3. **Launch**

Type ''minicom'' into the Ubuntu terminal:

```shell
$ minicom
```
Output example:

```txt
welcome 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**

Press ''Ctrl''+''A'', then ''Z'' to open the help 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.              |
+-------------------------------------------------------------------+
```
Press ''Q'' to exit ''minicom''.

```
+----------------------+
| Leave without reset? |
|     Yes       No     |
+----------------------+
```
Choose ''Yes'' and hit Enter to exit ''minicom''.


<WRAP info >
  * If the terminal output contains the following line, you need to use ''sudo minicom'': 

```sh
/dev/ttyUSB0: Permission denied
```
  * To access U-Boot, keep the USB-Serial-Debug tool connected, press the reset button on your device once. You should see output in your terminal, then quickly press the ''Spacebar'' or ''Ctrl+C'' to stop auto-boot. You will see the ''kvim#'' prompt when you have entered U-Boot.
  * Standard “help” commands are listed in the U-Boot Usage Guide. You will need to have a version of Android or Ubuntu installed on your device, available from our [[https://dl.khadas.com/Firmware/Krescue/images|official OOWOW]] images. 
</WRAP>

<tabbox Windows> 

1. Install Driver

Install the CH340 driver.

  - Download the [[https://dl.khadas.com/tools/CH34x_Install_Windows_v3_4.zip|driver]].
  - Unzip the compressed file.
  - Run the installer.

2. Install SecureCRT

Download the program from the [[https://www.vandyke.com/products/securecrt|SecureCRT]] website.

3. Setup SecureCRT

Before starting SecureCRT, connect the USB-to-TTL converter tool to your SBC and computer.

Launch SecureCRT and navigate to ''File'' -> ''Quick Connect'':

{{/products/sbc/common/development/securecrt1.png|securecrt1}}

Select the ''Serial'' protocol, choose the correct COM port (device node), set the baudrate to ''1500000'', and ensure ''XON/XOFF'' is not selected.

{{/products/sbc/common/development/securecrt2.png|securecrt2}}

Click ''Connect''.

{{/products/sbc/common/development/securecrt3.png|securecrt3}}

<tabbox Mac OS> 

1. Setup Meta key

Minicom requires a Meta key. To create one, open the Terminal application and go to ''Terminal''->''Preferences''->''Keyboard'', select Use Option as Meta key.

{{/products/sbc/common/development/minicom1_en.png|minicom1_en}} \\
{{/products/sbc/common/development/minicom2_en.png|minicom2_en}} \\
{{/products/sbc/common/development/minicom3_en.png|minicom3_en}}

2. Install

```shell
$ brew install minicom
```
Add access permissions
```shell
$ sudo usermod -a -G dialout $(whoami)
```
<WRAP info >
You may need to log out or reboot your system for changes to take effect.
</WRAP>

3. Setup

Connect the USB-to-TTL converter tool to your SBC and computer before setting up ''minicom''.
```shell
$ sudo minicom -s
```
You will 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 navigate to ''Serial port setup'', and press Enter to enter the ''Serial port setup menu''.

  * Press ''A'' to set the serial device, then press Enter to confirm.
  * Press ''E'' to set the baudrate, select ''1500000'' and press Enter to confirm.
  * Press ''F'' to disable hardware flow control, and set it to ''NO''.


After completing the setup, press Enter to exit the menu, then select ''Save setup as dfl'', and finally ''Exit from Minicom''.

<WRAP info >
The serial device node must correspond to the correct serial device node in macOS.
</WRAP>

4. Launch

Type ''minicom'' in the terminal:

```
$ minicom
```
Output example:
```
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

Press ''Ctrl''+''A'', then ''Z'' to open the help 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.              |
+-------------------------------------------------------------------+
```
Press ''Q'' to exit ''minicom''.

You will see:

```
+----------------------+
| Leave without reset? |
|     Yes       No     |
+----------------------+
```
Select ''Yes'' and press Enter to exit ''minicom''.

</tabbox>