> btwrite(0x7fff,BT848_GPIO_OUT_EN); // disable all outputs > btwrite(0x0000,BT848_GPIO_OUT_EN); // enable all outputs > btwrite(0x0000,BT848_GPIO_DATA); // set all outputs to /0 (+5V) > btwrite(0x7fff,BT848_GPIO_DATA); // set all outputs to /1 (0V) Each GPIO pin is basically a tri-state buffer. To use a GPIO as an output you must first enable the bit in the GPIO_OUT_EN register (1 = enable the pin for output). Once the output is enabled, writing data to the GPIO_DATA register should show on the GPIO pin. A '1' should drive a +5V logic high and a '0' should drive a 0V logic low. Each GPIO pin has an internal pull-up so all undriven GPIO pins will have a +5V logic high. So here is what your code should look like: btwrite(0x0000,BT848_GPIO_OUT_EN); // DISABLE all outputs btwrite(0x7fff,BT848_GPIO_OUT_EN); // ENABLE all outputs btwrite(0x0000,BT848_GPIO_DATA); // set all outputs to logic 0 (0V) btwrite(0x7fff,BT848_GPIO_DATA); // set all outputs to logic 1 (+5V) Mike
