fant sw: configure pull-ups for tacho inputs

main_fw/src/main.c

@@ -412,6 +412,10 @@ static void __xMR mytimercallback(const struct timer_task *const timer_task)
                         PID2.setpoint = FAN_RAMPUP;
                         PID3.setpoint = FAN_RAMPUP;
                 } else {
+			/* Pull-up tacho input, but only after fans started */
+			gpio_set_pin_pull_mode(PIN_PA17, GPIO_PULL_UP);
+			gpio_set_pin_pull_mode(PIN_PA16, GPIO_PULL_UP);
+			gpio_set_pin_pull_mode(PIN_PA13, GPIO_PULL_UP);
                         if (fan_cmdrpm[0])
                                 goal_pwm_duty1000_1 = pid_compute(&PID1, tacho_rpm[0]);
                         else