I'm trying to use GPIOs as outputs but they are toggling high at boot. I'm exporting GPIOs 11 & 13 after boot. But they go high before it gets that far into boot. This also happens with export the JTAG pins so I'm thinking its a Device Tree gaff. What am I doing wrong here?
pinctrl {
state_default: pinctrl0 {
gpio {
ralink,group = "jtag";
ralink,function = "gpio";
};
};
uartf_pins: uartf {
uartf {
ralink,group = "uartf";
ralink,function = "gpio uartf";
};
};
};
Hi!
You need a 10kohm pull down resistor (to gnd).
Best regards,
Daniel
Thanks Daniel - I connected the GPIO to the Relay 1 input (cut and jump on EVB). It didn't toggle before when it was connected to the RI_as_GPIO signal. But, now that the UARTF is operating as a UART with GPIO, I'm getting GPIOs going active/high during boot as the device tree settings are processed. The 10K resistor pull down makes sense - but look at the Relay1 input circuit - it has a 10K pull down. So, I am getting these GPIOs going high. This is also true for the JTAG GPIOs. I have tested the device tree with all gpio assignments deleted and the ports still end up high after the "pin-ctrl" stanza in the device tree is processed. I have to export the GPIOs and actively set them up as outputs in order to make them go low. This isn't how things should work. I'm stumped here.