OK, I will try Grove A and B. By the way, what's the signal level of UART on Fire? I suspect it's not compatible with RS232 signal. (I see some microcontrollers need a converter to convert between TTL and RS232).
I'm trying to use the UART port (grove C) on the Fire to talk to my computer. My computer use a FTDI USB-RS232 converter to generate the serial signal.
I found I can detect some signal from the fire on my computer, but Fire cannot read the signal from computer. (I used pyserial to send the signal from my computer)
I guess it's because UART is not compatible with RS232 signal but I'm not sure. Please help if you have related experience.
Thank you for you quick answer. Looks like you're referring to the Arduino library of M5Stack.
I wonder if there is an equivalent function in UI-FLOW? I'm currently using UI-Flow to program my Fire.
I can also try to burn the Arduino firmware, but I'm worried if I can control the UI as easily as in UI-Flow.
I'm designing a Fire application which is supposed to be work on battery, and it will be beneficial if I can deep sleep Fire when it's not being used. Is there a way to "Sleep" the unit? Or what's the most common way to reduce power consumption?