Bluefruit with TX2 (serial communication)

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Hi!

I’m trying to use the TX2 dev kit with a Bluefruit LE UART friend. This device only needs simple serial command.

I connected the RX pin to the pin 8 of the j21 and the TX pin to the pin 10 of the j21. I can’t get it to work. When I start the Bluefruit before the TX2, the TX2 get stuck on the NVIDIA logo. And if I start the Bluefruit later, I don’t see any new file in the /dev folder. I tried to use the /dev/ttyS0, ttyS1, ttyS2, TTYS3 but none of them work.

I tried it with this configuration:

import time
import serial

# configure the serial connections (the parameters differs on the device you are connecting to)
ser = serial.Serial(
    port='/dev/ttyS0',
    baudrate=9600,

    parity=serial.PARITY_ODD,
    stopbits=serial.STOPBITS_TWO,
    bytesize=serial.SEVENBITS
)

Because of some deadlines, I really need to get that fixed ASAP!

Thank you for your help!
Quentin

2

hello quentin.boulanger,

please refer to [url]https://www.jetsonhacks.com/2017/03/24/serial-console-nvidia-jetson-tx2/[/url] for Jetson-TX2 serial console connections.
please note that the connection speed is 115200/8N1

you may also check similar topics Topic 1009901, and Topic 1026663 for reference.
thanks

3

Hi!

Thank you for your answer. Unfortunately this tuto explains how to use TX2 with a computer not how to use TX2 as an host. I finally decided to use an FTDI between my Bluefruit and my TX2 and that works. I have it in /dev/ttyUSB1

Have a nice day!

4

FYI, the dev board J21 connector UART is for serial console. Won’t work unless you go through a lot of effort to disable this in both Linux and U-Boot. J17 (“/dev/ttyTHS2”) is free to use though.

5

Thank you linuxdev! That makes sense. Would the communication be faster if I use the J17 port instead of the FTDI? My question is: Is there a delay when using the FTDI that I wouldn’t have with the J17? I just don’t know.

Thanks!

6

I don’t think you’d see much difference. Above 115200 you could have some advantages with the FTDI. Basically the internal UART requires two stop bits above speed 115200, and the FTDI might work without that. Other than that the two should be nearly identical.

7

Perfect! Thank you very much for your help @linuxdev!

Quentin