I am using a Microchip Bluetooth Pictail and a Sparkfun 3.3V USB-to-UART and a Arduino Uno (just for power-5V,gnd and 1 active high signal connected to 3.3V).
When I power the PicTail it outputs "CMD" to Realterm, but won't accept input (like a "H\n" for help). I see the Tx pin light up on the Sparkfun. The weird thing is, when I disconnect the 5V, it works great for like 10 seconds. I know it's running off bypass caps. Has anyone an idea what could be wrong? I checked the regulator output on the PicTail, its 3.3V, like it should be.