Grove AI Hat UART Issues

jeremy882 · August 21, 2019, 9:04am

~~yokonav post_id=55428 time=1565668652 user_id=13948:~~

RPI 3B+ is powered using 2.5A/5V adapter.and is attached to the Grove AI Hat. The J4 toggle button is ON so the Grove AI Hat gets power from the RPI.
The CH340 UART port is not showing in the Arduino IDE or by using ls -l /dev/tty.*. When I power the Grove AI Hat directly and keep the J4 toggle button at ON position and not powering RPI directly, the UART port appears. I want to power RPI separately but I can't keep the J4 toggle button at ON position when powering both separately. If I keep the J4 toggle button at OFF position while powering both separately the UART port disappears again. Also, the RPI is not booting up by powering from AI HAT (this behaviour is random, I believe due to insufficient power from AI hat side). I am using MacBook Pro.

Hi Yokonav,

Thanks for the feedback, and I apologize for my late reply. To make it more clear, I made a summary as below.

J4 Toggle ON,
~~[list]~~

Only use Pi to power, can’t read CH340.

Only use AI HAT to power, can read CH340, but Pi is not booting up randomly.

[/list]

J4 Toggle Off,
~~[list]~~

Power both, can’t read CH340.

[/list]

It is might because of the insufficient power from the AI HAT, and may also because of the CH340 chip because we have also received some technical issues about using CH340 on Macbook Pro. We will make some investigation and get back to you later.

To solve this issue temporarily, please choose the J4 toggle ON and use the AI HAT to power, since the “not booting up” happens randomly. If it is possible, would you please also try using this product on Windows and see if the same issue happens? Thank you!