Hi all, I am new in this forum so please correct me if I miss something. Currently I am struggeling with some modifications on an already working project from https://github.com/luigif/hcsr04 where a HCSR04 sonar is triggered via PRU. The sample works fine and I tried to move this to different pins because in the end I will need several of the sonars for my project. To move the sample to pin P9_27 (as trigger pin) and P9_31 (as echo pin) I adjusted the dts file and a of course the .p file accordingly. Accidantally I found the modified sample working when I set the GPIO pin manually to an output pin in /sys/class/gpio/. At the moment I remove the gpio pin from /sys/class/gpio the sample stops working again. Its strange to me because the output from my pin configuration looks correct after loading the overlay: cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins ... pin 115 (44e109cc) 00000007 pinctrl-single ...
Pin 115 (P9_27 as GPIO3_19) is set here as mode7, pull down enabled and output. But loading the overlay does not pull the the pin to ground as I can see with a multimeter. Has someone any idea? More info: I work with a BBB in revision C.1 on kernel 3.8.13 (bone47) My dts configuration: /dts-v1/; /plugin/; / { compatible = "ti,beaglebone", "ti,beaglebone-black"; /* identification */ part-number = "hcsr04_2"; version = "00A0"; exclusive-use = "P9.31", "P9.27", "gpio3_14", "gpio3_19"; fragment@10 { target = <&am33xx_pinmux>; __overlay__ { pinctrl_hcsr04_2: pinctrl_hcsr04_2_pins { pinctrl-single,pins = < /* Table of mux options: Bit 0 \ Bit 1 |- Mode Bit 2 / Bit 3: 1 - Pull disabled, 0 - Pull enabled Bit 4: 1 - Pull up, 0 - Pull down Bit 5: 1 - Input, 0 – Output */ 0x1CC 0x07 /* Trigger: P9_27 gpio3[19] GPIO115 out pulldown Mode: 7 */ 0x1B8 0x27 /* Echo: P9_31 gpio3[14] GPIO110 in pulldown Mode: 7 */ >; }; }; }; fragment@11 { target = <&ocp>; __overlay__ { hcsr04_2 { compatible = "bone-pinmux-helper","gpio","pruss"; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_hcsr04_2>; status = "okay"; }; }; }; fragment@12{ target = <&pruss>; __overlay__ { status = "okay"; }; }; }; Thank you in advance! -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.