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UART interface using the Tinkering Kit
There are two UART ports on the C2.
They are 3.3Volt (LVTTL) interface and there is no 5Volt tolerance.
The first one is mapped to /dev/ttyS1 which is connected to 40-pin header Pin #8 & #10 & ground pin.
The second one is mapped to /dev/ttyS0 which is connected to Serial Console Port CON5.
How to test external UART pin on the 40-pin header
You need to prepare below items.
- ODROID-C2
- USB-UART Module Kit
- jumper wire x4
- serial comunication utility on your Host PC
You will connect jumper wire as below picture.
Connect the USB-PORT of USB-UART Module to your HOST PC
The RXD and TXD must be twisted each other.
1. HOST PC setup.
You will open USB Module Device on your HOST PC.
Ubuntu
Install serial comunication utility.
sudo apt-get install minicom
After check your usb serial node, Open serial port.
ls /dev/ttyUSB* sudo minicom -b 115200 -D /dev/ttyUSB0
2. Target board(ODROID-C2) setup.
Set a serial node on your ODROID-C2
stty -F /dev/ttyS1 115200
3. ODROID-C2 → HOST PC test.
ODROID-C2
echo 1 > /dev/ttyS1
4. HOST PC → ODROID-C2 test.
ODROID-C2
cat /dev/ttyS1
HOST PC
Send characters via minicom.
Pin Map : UART pin on the 4-pin CON5 connector
_____UART____ | | |Pin 4 - GND| |Pin 3 - RXD| |Pin 2 - TXD| |Pin 1 - VCC| |_ | |_________|
3.3V LVTTL
Another UART port on 40pin header
If you don't use the I2C interface(i2c-1) on pin#3 & pin#5, you can use them with UART2.
Just follow user “campbell”'s development note to have a new UART-2port on /dev/ttyS2.
Note that Pin#3 is Tx and Pin#5 is Rx.
How to enable a third UART ttyS2 by "campbell"
Automatically configure the UART settings.
This is an example of default setting for a GPS module which has a 9600bpsN81 UART interface.
Add the following to the end of /etc/rc.local (before the exit 0)
/bin/stty -F /dev/ttyS2 raw 9600 cs8 clocal -cstopb > /dev/null 2>&1
This way the tty port is setup for use with the gps on system boot, without user interaction.