Blocking spi transmission with MOSFET or transistor?

Discussion in 'The Projects Forum' started by Avshi, May 19, 2015.

  1. Avshi

    Thread Starter New Member

    Jan 16, 2015
    Hello All! I'm working with the esp8266 connected to an mcu. I want to block the data lines to the mcu when I plug in a usb-serial converter (for flashing and debug purposes) possibly with p-channel fets or transistors connected to the 3.3v from usb. Is this a good idea or will the fets cause too much distortion or voltage drop when the mcu talks and listens to the esp8266?

    UPDATE: I found that I can route the 3.3v input to an interrupt on the mcu and disable spi on the rising edge and enable on falling edge.
    Last edited: May 20, 2015