I want to control the standby state of an LCD panel through an android media PC. I'm thinking of using a Trinket as a cheap android USB peripheral. Is this possible? Or should I be looking at an FTDI module?

I'm new to Android, Adafruit and USB but really keen to learn. Previously, I controlled my LCD panel through my Raspberry Pi GPIO interface, but I want to move to some hardware with a little more oomph!

The LCD Panel accepts a 3.3v signal to switch the screen on. Is the Trinket the right piece of hardware for this application?

Thanks in advance for any help you can offer.

Best Regards, Jabah


This question should really be asked on the Adafruit forums, especially as it relates to a question about a specific product.

That said, note that the Trinket only supports USB 1.1 so it won't show up as a virtual serial port, so talking to it requires going through the USB subsystem instead of the simpler serial device API.

If the Rpi is working, why switch?


The Adafruit Trinket's bit-bang USB implementation is only intended for programming the device. Out of the box, it does not support runtime communication over USB from a user program, presumably because integrating the tricky bit-bang USB device code with the sort of Arduino framework libraries the expected users would depend on for serial communication seemed too challenging.

Of course, it is possible to implement your own USB communication, most obviously by developing a bare metal program incorporating bit-bang USB code, and building it with a linker map which avoids conflict with the bootloader (or even replacing the bootloader in favor of another loading mechanism).

Of course, the device-side of USB is only half the battle. You also need an Android device with OTG hardware and software support such that it can function as a USB host. You may also require an adapter cable with the ID pin grounded, and possibly more obscure equipment or cleverness if you want to power the Android device via its USB port while it is acting as a host.

For a mere on-off control, you can probably accomplish something driving an op-amp or simple micro controller from the headphone jack...


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