On 5/25/2017 11:57 AM, Alexey Volkov wrote: > Hello > > Is it any ways to make the board to switch GPIO's low on the power up and the > Linux boot before the Machinekit starts? > What it is by default, High Impedance?
The I/O pins will be high impedance with a week pull-up resistor until the FPGA is programmed. You can program the FPGA with the boot-loader if you can't wait for Linux to boot and load the bit-file via a device-tree overlay, but you will still have several seconds before the FPGA pins are active. Your hardware should be designed such that the system defaults to a safe state when the FPGA is not programmed. The Mesa manuals all have a section on this. From the 5i25 manual: <quote> STARTUP I/O VOLTAGE After power-up or system reset and before the the FPGA is configured, the pull-up resistors will pull all I/O signals to a high level. If the FPGA is used for motion control or controlling devices that could present a hazard when enabled, external circuitry should be designed so that this initial state results in a safe condition. </quote> -- Charles Steinkuehler char...@steinkuehler.net -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
