Some one mentioned this in another thread.
In the Intel for Edison Kit for Arduino Hardware guide page 9 there i a statement.... "All GPIO pins on the Arduino* header require some internal GPIOs to be set up before the pin is usable. This is usually as simple as setting an output enable, pullup enable, and mode. However, some pins have extra functionality such as SPI, PWM, or I2C, so these pins need extra multiplexing (muxing) in order to be usable."
Then on page 31, there is a list of steps to enter into linux as shown to enable the edison for SPI...
I had to do a shell call for setting the GPIO pin.And now I am getting output voltage on the pins. But I want to interface a 3.3V device to the Intel edison arduino board. The output voltage on the pins is at 5v but I want only 3.3V output. Is there a way to level shift it down so that the board works with 3.3V electronics?
I read here
that he can also interface 3.3V hardware.
"The digital IOs and analog pins can be configured to operate at either 5V or 3.3V."
Says some jumper to be set but I do no know which
It seems that you already found an answer but in case someone else has the same doubt, the jumper to configure the IO pins as 3.3V tolerant is the one labeled as J9 (IOREF). More information about the jumpers on the Edison Arduino board can be found here: Intel® Edison Boards — Jumper Headers