I have been working on file transfer through the USB Port and have made a program that will copy any file (currently limited to 512KB and below) from SD card to the HP Prime. You just enter the filename and the amount of bytes that you want to copy of it.



There is currently a lot of storage on the HP Prime, but given it's processing power, you can quickly gather a large amount of data, this is an external storage option. It's fast enough I suppose, I think it is now limited by the speed of the BASIC programs that we can run on the HP Prime.

This is good stuff, thanks for sharing. For those of us who don't write HP Prime software too frequently, how does this work? Does the BASIC language have commands to communicate with USB serial devices over the USB port, or is there something more complex happening?

Yeah, the HP Prime PL has got 3 simple USB HID commands. USBOpen() which allows the device to connect to another USB device over its USB port. USBRecv() which returns the last 64 bytes in the HID buffer and USBTrans() which sends up to 64 bytes at a time.

Then on the Arduino end, the Arduino Leonardo can act as a USB host, and along with the Arduino HID Project library, it can send and receive raw HID data.

The combination of the 2 obviously opens up a whole world of interfacing capabilities as the Arduino has a massive amount of i/o and libraries, this is just one of the recent projects I have been playing with using a combination of the 2.