I am currently trying to connect to my Raspberry Pi B+ from my Macbook Pro (El Capitan) using the following TTL USB cable: https://www.pi-supply.com/product/usb-ttl-serial-cable-debug-console-cable-raspberry-pi/?aelia_cs_currency=GBP&feed_country=GB&gclid=CP-p6tLqlc0CFbcW0wodzGoIqA

After completing the 0xc0de's tutorial (http://www.0xc0de.net/2015/09/getting-adafruit-serial-cable-to-work.html), my computer could recognise the new hardware under "cu.usbserial".

However, when I try to connect using the computer's terminal (typing: screen /dev/cu.usbserial 115200), I get the following errors instead of the expected login prompt:

    [ 6297.097173] systemd[1]: Unit systemd-journald.service entered failed state.
    [ 6287.029730] systemd[1]: systemd-journald.service has no holdoff time, scheduling restart.
    [ 6287.044138] systemd[1]: Stopping Journal Service…
    [ 6287.056453] systemd[1]: Starting Journal Service…
    [ 6287.082128] systemd[1]: Started Journal Service.

The above messages are repeating continuously.

The rasperrby Pi is running a fresh version of Raspbian (Jessie), which is perfectly working when connecting through SSH.

Does anyone have any idea/advices about how to solve this problem ? Please don't hesitate to ask any additional information.

Best regards

EDIT: I get the exact same error when connecting using the application called "SerialTools" (freely available the AppStore) instead of the computer's terminal


1 Answer 1


If it can help anybody, I finally solved my problem by powering the raspberry pi with an external power source while leaving disconnected the VCC pin of the TTL cable (red jumper).

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