I think in CG20calculator adds Bluetooth function, program on FX-CG20 onboard data lines are transformed by connecting an external Bluetooth adapter, will be on the USB data line improvement or3PIN excuse data line transformation? If this is successful, then do a simple SDK program should be able to send instructions to Bluetooth adapter. Who is interested can communicate with me, I can provide funds! Thank you.

Email:lingyang1122@vip.qq.com

That was very garbled, but let's see. Bluetooth would probably be best done over I/O port, as I don't think the prizm can do USB host mode. (Still not entirely convinced of that, though)

As far as I can tell, you're asking if the 3-pin I/O port or the USB port would be better for implementing Bluetooth. First of all, if you'll need 5V power, you have to leech it off the USB port, as the serial I/O port supplies no power. Secondly, if you use the I/O port, be aware that it can only transmit on one line and receive on the other, so you'll need intermediate adapter hardware to use it for USB. Thirdly, from reading various Renesas datasheets, I believe that the CPU can indeed enter USB host mode over the same set of pins, but I'd have to re-read and experiment to be sure. Bottom line, I don't think the I/O port can do what you want, and while I'm not sure that the USB port can either, I think you have a better shot with it.

My main concern for USB is the amps requirement. I know that the TI-84 could only give off 100 mA. I doubt the prizm could do much better, especially if it's not designed to go in USB host mode. In fact, if it's not designed to go in USB host mode, they might have just not put a 5V rail on it at all, and assumed the device was always going to be a peripheral.

Well, you could open up the case and do some tinkering if you're hardware savvy.

I would do it if it wasn't my only prizm. If someone gave me one, I would do it.

EDIT: Set the post to notify me for replies.