Briefly, if you cannot type into your iPhone with a Bluetooth keyboard, temporarily turn off the quick navigation option.
When the quick navigation option is on in iOS 8.1.1, no typing of digits or text can be done to text field. You need to activate the text field first to turn it off. When the screen is locked, however, there's no way to activate the input text field for the unlock code. Thus, to be able to type the unlock code, you need to manually turn off the quick navigation option, then type the unlock code, and then turn it on again for your convenience. FYI, the option can be toggled on and off with L1 and B7 combination with a RiVO keyboard, and the left and the right key combination with a normal Bluetooth keyboard.
Likewise when you want to type phone numbers directly in the Keypad tab of Phone app, you cannot activate the input text field for phone numbers. You need to do the same procedure as above. If it still doesn't work out, try switching to other tabs like Recents tab, and then back to Keypad tab again. It has been a long-lasting iOS bug.
Sometimes when you cannot type text into a text field after activating it, iOS seems to have a bug not to turn off the quick navigation option when you activate the text field. In this case you may follow the same procedure as above.
The above can be found in the RiVO Troubleshooting Guide (http://goo.gl/APVJWn) as well as some other issues you might have while using the RiVO keyboard or any other Bluetooth keyboard.
Have a good day.