Libre Computer Wiring Tool

Hardware
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1

To install via apt:

sudo apt update
sudo apt install libretech-gpio libretech-dtoverlay

libretech-gpio
To get a list of headers for your board:

lgpio headers

To get a list of the header pins for a header:

lgpio header HEADER

For getting the information for a pin number on the main GPIO header of the board:

lgpio info PIN#

For getting the information for a pin number on a specific header of the board:

lgpio info HEADER PIN#

For getting the libgpiod chip and line number for a pin on the main GPIO header of the board:

lgpio info PIN# gpiod

For getting the deprecated sysfs export GPIO number for a pin on the main GPIO header of the board:

lgpio info PIN# sysfs

For conversion from existing Raspberry Pi BCM numbering:

lgpio bcm PIGPIO#

For quickly getting the GPIO level of a specific pin on the main GPIO header of the board:

sudo lgpio get PIN#

For quickly getting the GPIO level of a specific pin on a specific header of the board:

sudo lgpio get HEADER PIN#

For quickly setting the GPIO level of a specific pin on the main GPIO header of the board:

sudo lgpio set PIN#=0 or 1

For quickly setting the GPIO level on multiple pin on the main GPIO header of the board:

sudo lgpio set PIN#=0 or 1 PIN#=0 or 1

For quickly setting the GPIO level of a specific pin on a specific header of the board:

sudo lgpio set HEADER_PIN#=0 or 1

For quickly setting the GPIO level on multiple pin on specific headers of the board:

sudo lgpio set HEADER_PIN#=0 or 1 HEADER_PIN#=0 or 1

We do not recommend using lgpio get or set as an API call since the overhead is high. It also does not support pinctrl biases like gpioget/gpioset commands from the gpiod package does. Please use the libgpiod or sysfs numbers from the lgpio info command with standard libraries for libgpiod or sysfs.

libretech-dtoverlay
List Device Tree Overlays

sudo ldto list

Enable Device Tree Overlays

sudo ldto enable OVERLAY #enable temporarily, not applied on next boot

Disable Device Tree Overlays that were applied temporarily, some hardware overlays cannot be disabled once active and require reboot.

sudo ldto disable OVERLAY #disables temporarily enabled overlays

Merge Device Tree Overlay permanently on every boot, applied on next boot

sudo ldto merge OVERLAY

Remove all permanent Device Tree Overlays, applied on next boot

sudo ldto reset
sudo reboot

You must reboot in order for the system to reset before merging new device trees. Otherwise, the device tree may become corrupted resulting in a system that will fail to boot. In this case, you must remove the dtb folder on the first partition of the storage device.

Overlay Descriptions

Using Upstream Repo for Custom Device Tree Overlay
To install git version:

sudo apt install git
git clone https://github.com/libre-computer-project/libretech-wiring-tool.git
cd libretech-wiring-tool
sudo ./install.sh

To update git version:

cd libretech-wiring-tool
git pull origin master
make

If you have an addon device you would like supported, please post below.

7 Likes
2

This should be set instead of get, correct?

1 Like
3

Fixed in the documentation. Thanks for pointing out the typo.

4

Does this tool work on armbian? I keep getting “No vendor found!” message

5

This is designed for first party images only.

6

Hello! Thanks for putting this information together.

I have a Le Potato 64bit running 2022-09-22-raspbian-bullseye-arm64+aml-s905x-cc.img.xz.

When following these instructions, I am able to do some of the commands but the “get” and “set” commands do not work.

For example,
sudo lgpio get 7J1 3
results in
gpioget: symbol lookup error: gpioget: undefined symbol: gpiod_is_gpiochip_device

I am struggling to find a resolution to this. Please let me know if you have any ideas. Thanks!

7

Just tried this on the lite image and it worked fine. Did you modify the image in any way or try to install something beforehand?

8

Thanks for the reply and testing it!

I was testing other GPIO libraries such as (ArmbianIO

That may have interfered with this? I didn’t change anything with the Raspbian image either.

I did find in this website’s forums a link to this Working Python GPIO library This has been working for me using python on the le potato!

9

The default Debian gpioget and gpioset definitely works. You probably modified something on the image and removed a library or something.

The official package is python3-libgpiod: Debian -- Details of package python3-libgpiod in bullseye
It is maintained by upstream and already integrated into Debian and derivatives proper.

10

Probably, I am very new to the Le Potato and only so-so on the Raspberry Pi. Appreciate the help!

1 Like
11

Hello. I’m trying to get a GPS module to work with Le Potato.
I’m running Raspbian 6.0.11.
I was able to get uarta connected to the GPS module using the ldto tool.
sudo ./ldto enable uarta
sudo ./ldto merge uarta
The serial ports on GPIO pins 8/10 show up as /dev/ttyAML6
This is now referenced in the /etc/default/gpsd.
DEVICES="/dev/ttyAML6 /dev/pps0"
Using the gpsmon tool, the NMEA sentences are displayed correctly.
I am trying to connect a GPIO pin for the PPS input.
In the Raspberry Pi version, this connection is added in the /boot/config.txt
dtoverlay=pps-gpio,gpiopin=12
I would like to use pin 12 of the 7J1 connector for the PPS input.
How can I connect this GPIO pin to the gpsd daemon?
thanks

12

You have to clone the wiring tool repo, write an device tree overlay for that specific pin, and then enable/merge it. Then it should work. PPS GPIO is already enabled in the kernel.

13

hi I’m a little lost trying to get used to using the s905x-cc. i have several python codes that i used to run on the raspberry pi that i would like to run on the s905x-cc, but I’m lost at what code/ library i need to use in python3 to control the GPIO pins.
should i start here with this wiring tool or if there is documentation that i can be pointed to so as i can get answers. thanks in advance

14

We will write a guide for this because you are not the first one to ask. It will be here: WIP: How to control GPIO via Python 3

It should get completed in the next two or three days.

2 Likes
15

Can i get help with a dtsoverlay to enable OTG for HID (keyboard/mouse)? Does this look correct?

/dts-v1/;
/plugin/;

/ {
        compatible = "libretech,cc", "amlogic,s905x", "amlogic,meson-gxl";
        part-number = "s905x-cc-otg";

        fragment@0 {
                target = <&usb_otg>;

                __overlay__ {
                        dr_mode = "otg";
                };
        };
 };
16

You can find the DT here: https://boot.libre.computer/ci/aml-s905x-cc.dts

The part-number and target are both incorrect.

https://wiki.st.com/stm32mpu/wiki/OTG_device_tree_configuration#DT_configuration_example_as_high-speed_OTG_in_Host_or_Peripheral_mode-2C_with_micro-B_or_Type-C_connector-2C_and_with_VBUS_and_ID_left_unconnected

17

Thank you for this information. Does this look correct?
/dts-v1/;
/plugin/;

/ {
compatible = “libretech,cc”, “amlogic,s905x”, “amlogic,meson-gxl-usb-ctrl”;

    fragment@0 {
            target = <&dwc2>;

            __overlay__ {
                    dr_mode = "otg";
                    status = "okay";
            };
    };

};

18

I recommend you open a new thread about this so that it’s searchable. The USB tree is a little complex and I don’t think that’s right.

		usb = "/soc/usb@d0078080";
		dwc2 = "/soc/usb@d0078080/usb@c9100000";
		dwc3 = "/soc/usb@d0078080/usb@c9000000";

I think usb@c9100000 is the device in question. You have to read more on the Linux documentation about the dwc2 driver.

19

I keep seeing the “No vendor found!” error as well. I am running an image I downloaded from https://libre.computer/products/aml-s905x-cc/ > Downloads > Armbian.

If that’s not “first party,” can you clarify what a “first-party image” is?

Is there a way to enable and control PWM on Armbian without ldto?

20

Armbian does not support our tooling. First party images are those found on distro.libre.computer.