UART
Last updated
Last updated
LinkIt 7697 provides two UART(Serial) interfaces, they are:
UART0 (P0 and P1 on the board). This port also connects to the onboard CP2102N USB-to-UART converter. You can use the Serial class in Arduino to access this port. You can read and write to this port using the Arduino Serial Monitor.
UART1 (P7 and P6 on the board). This port maps to the Serial1 class in Arduino. Note that it's not connected to the onboard USB-to-UART converter, so you need to connect it to another USB-to-UART converter.
Open File > Examples > 04. Communications > ASCII table and upload it.
After uploading the sketch, click the Serial Monitor button on the toolbar, as shown below.
3.Set the baud rate to 9,600 as declared by the sketch Serial.begin(9600);
4.The output window in Serial Monitor should now display a list of ASCII values, as shown below:
Note that although the board automatically resets the MT7697 and runs the sketch after uploading, you won't see any output in the window if you open Serial Monitor after the sketch has already executed . This is why you need to press the RST button in this step.
5.The output window in Serial Monitor should now display a list of ASCII values, as shown below:
As an experiment, you can change Serial to Serial1, and the output will be redirected to P6/P7 on the board. You need to use a separate USB-to-UART dongle to read the output.
You may use other terminal applications to connect to the Serial port. Note that you need to turn off the Flow control setting, since RTS and DTR states are reserved when uploading sketches to the board. If they are not set correctly, you may not be able to boot up the board correctly. Instead, you'll only see "CCC" output in the terminal application. Two examples are shown below when using PuTTy and eagleCom:
In PuTTY, the Flow control field needs to be turn off.
In eagleCom, pull down the DTR and RTS signals.
A detailed explanation can be found in the document for MT76x7 uploader script.
