Questions tagged [device-tree]
a Device Tree (DT) is a description of the hardware in a system
48
questions
1
vote
1answer
69 views
Error when connecting more than ten USB devices on Raspberry Pi 4 [duplicate]
What is the limit of USB devices in raspberry pi4?
We have an external USB hub with its power supply and 10 devices fall off with errors.
[Wed Mar 11 09:04:43 2020] usb 1-1.3.4-port1: Cannot enable. ...
0
votes
1answer
56 views
Re configuring GPIO pins for SPI protocol
GPIO pins 19,21,23,24,26,35,38,40 are dedicated for SPI protocol. Is it possible to use other GPIO pins for SPI? If yes, how do we do it?
1
vote
0answers
60 views
Applying dwc2.dtbo to bcm2711-rpi-4-b.dtb at build time triggering FDT_ERR_NOTFOUND
I'm trying to build a NixOS image for my Raspberry Pi 4b with the dwc2 device tree overlay applied.
Per advice from the #nixos-aarch64 IRC channel, doing this the Nix Way calls for configuring ...
0
votes
0answers
122 views
(Pi4) No Display when in OTG mode unless HDMI_safe=1
Im officially stumped. I have connected my Pi4 to my PC via USB to USB-C for OTG connection. Whenever I boot with the normal PSU to the USB-C port on the Pi4, everything boots correctly (display and ...
0
votes
1answer
52 views
Trouble adding a gpio device to the device tree
I'm trying to connect an hx711 to GPIO23 and GPIO24 pins on an RPI3 A+, and I need to specify this in the device tree to have the hx711.ko driver be probed. I've been stuck on this problem for some ...
2
votes
1answer
47 views
Why DMA uses bus address rather than physical address?
Why DMA uses bus address rather than physical address?
And do we provide bus address or physical address in the device tree?
Where do we get to know these addresses that needs to be provided to the ...
1
vote
0answers
115 views
Creating a Device Tree Overlay for i2c device
I'm trying to create a Device Tree overlay for a i2c touch screen.
Things are a bit strange as the screen is a 16bit DPI so all usual i2c pins are consumed. I'm using a i2c-tiny-usb adapter to get an ...
0
votes
0answers
20 views
I2C client driver instantiation using Device Tree - probe did not get called
I am writing a sample and simple i2c driver in which I am trying to instantiate the
i2c client device using device tree overlay. I have got some DTE overlay sample which i have complied to .dtbo and ...
0
votes
0answers
126 views
Simple Sound Card with I2S - how do I switch frequencies?
I asked this a month ago, but didn't get an answer and so the thread was auto-deleted. It is becoming critical that this be solved, so I am reposting.
I have the simple sound card working with a ...
0
votes
0answers
61 views
Using waveshare LCD and SPI1 for LEDs
My problem is that I cant get SPI1 and the LCD screen to work at the same time.
Only SPI1 with the spi1-1cs overlay worked and only the waveshare35a overlay working, I tried to make my own overlay ...
1
vote
1answer
145 views
Can I run 2 device tree overlay at the same time?
I'm trying to monitor some 4-20mA current loops and 0-10V generators with a RPi 3. I found these modules which would do the job:
https://widgetlords.com/products/pi-spi-2a0-raspberry-pi-analog-output-...
2
votes
1answer
76 views
Building an old kernel is not possible because the arch/arm/boot/dts/overlays/ directory does not exist
I've been trying to build a kernel from the 4.14.85 version. I followed the instructions from the official documentation but instead of using the latest version you can find in the repository I ...
1
vote
1answer
392 views
Use internal pull up resistors with the gpio-keys module in the device-tree
I have an external board with some buttons that are attached to gpio 20 and 21 which connects these pins to ground when pressed:
simulate this circuit – Schematic created using CircuitLab
I'd ...
3
votes
1answer
571 views
How do I add an i2c device to the device tree?
I am trying to add an mpu 9250 to the device tree of my RPi 3 A+ so that my custom driver's probe function will be called. I have followed this documentation about the Raspberry Pi device tree and ...
0
votes
0answers
49 views
What could trigger the removal of the WiFi device?
I discovered this morning that wlan0 on my RPi vanished during the night (at 04:14:13 in the unaltered log below):
Dec 18 03:38:46 rpi1 wpa_supplicant[407]: wlan0: WPA: Group rekeying completed with ...
0
votes
2answers
883 views
gpio-shutdown doesn't seem to have an effect
We are trying to have the Pi shut down gracefully when power is removed. We have a battery connected so that it will have time to shut down. So far, our attempts to use gpio-shutdown have been ...
4
votes
3answers
4k views
Emulate Raspberry Pi zero W with Qemu failed due to missing dtb
I am trying to emulate a Raspberry Pi zero W with Qemu based on an image I used on a real Raspberry Pi zero W.
The command I am using is:
sudo qemu-system-arm \ ...
0
votes
0answers
351 views
Connecting RAW NAND through GPIO
I'm trying to define a device tree for connecting an external raw NAND using GPIO on RPI3.
I found that there are available drivers, and I found an example in the sources' "Documentation" directory
...
1
vote
1answer
352 views
How and from where is the ENC28J60 driver loaded?
I have a raspberry CM3 setup where I added an external eNet port so that I have internet connectivity. It is very similar to the break-out board setup such as this one which is also based on the ...
1
vote
2answers
4k views
Rpi3 is the hardware watchdog enabled by default
I have RaspberryPI's 3 (running both Jessie and Stretch) and tested on both
In order to enable the watchdog timer, In many posts I saw that add in the /boot/config.txt a line with:
dtparam=watchdog=...
2
votes
1answer
357 views
Change Device Tree to pullup pin at boot
I trie to add a LTC2954 to the raspberry pi zero w. I designed and produced a prototype pcb with an lipo management system for load and loadsharing. My problem is, that the KILL Pin of the LTC2954 has ...
0
votes
0answers
157 views
Difference between sound and audio nodes in RPi 3 device tree?
I looked a bit into the device tree of Raspbian 9 on Raspberry Pi 3, using:
dtc -I fs /proc/device-tree > myrpi-dev-tree.txt 2>&1
I've noticed there is a node called audio:
audio {
...
2
votes
0answers
192 views
Raspberry Pi remap DPI pins [closed]
I'm trying to hook up my Raspberry Pi a to custom display hat via the parallel display interface (GPIO Pins, not ribbon cable). The problem I'm facing is that the DPI pins are rather awkwardly placed ...
1
vote
0answers
121 views
Access more than two (2) slaves on spi0
Supposedly, there is a new driver that supports arbitrary GPIOs for SPI0 channel select, that is configurable via the device tree.
Everything I try only half works. The hard works. If I toggle the ...
2
votes
0answers
391 views
Accessing 3+ SD/MMC /dev/mmcblk devices
I've successfully followed some instructions for access 2 SD cards via SPI on a Raspberry Pi 3: https://ralimtek.com/Raspberry_Pi_Secondary_SD_Card/
How do I configure it to access more than 2 SD ...
1
vote
0answers
118 views
In simultaneous use of SPI0 and DPI Mode 3 interfaces, can SPI0 CS0 be moved to a pin other than 8?
I am attempting to design a device using a Pi Zero which needs to connect to both an ENC18J60 SPI ethernet controller, and a VGA monitor via Mode 3 DPI and the Mincepi Pi Zero pi2vga schematic. While ...
1
vote
1answer
1k views
dtoverlay=gpio-poweroff not working on raspberry pi 3 B
Problem:
I have a Raspi 3B rev: a02082 (Q1 2016 3 Model B 1.2 1 GB (Mfg by Sony)) running raspbian jessie kernel 4.9.35-v7
I want to signal to a power management circuit that filesystems ...
0
votes
0answers
515 views
SPI doesn't work because of device tree
I have the same problem as this person:
SPI enabled in device tree, but I can't use it
I tried commenting in the original thread but the community rules don't allow me to comment because I don't ...
1
vote
1answer
2k views
How do i use DeviceTree to init GPIO to a set value?
Hello i've got a board connected to my raspberry pi 3 and according to the pin set on boot of the raspberry this shield reboot which is problematic. I need to be able to reset the board and control ...
3
votes
1answer
58 views
DeviceTree magic strings
I recently stumbled over the MagPi Essentials Camera. In chapter 7 "Flash photography using an LED" (p.41+), they show how to configure pin BCM17 to act as a flash for the official Raspberry Pi Camera....
2
votes
0answers
436 views
device tree and led blink
I am trying to create one led driver via device tree in Rpi 3
I had created the dtsi file
/dts-v1/;
/plugin/;
/ {
compatible = "brcm,bcm2837";
fragment@0 {
target = <&...
4
votes
1answer
4k views
SPI enabled in device tree, but I can't use it
I am trying to use SPI interface on Raspberry Pi 1 B (OS: Raspbian July 2017, kerenl 4.9.5). To do this, I am using wiringPi. I confirmed that wiringPi works via gpio readall
To load SPI:
gpio load ...
0
votes
2answers
1k views
How to use advanced GPIO functions via sysfs?
The GPIO ports can be accessed using sysfs interface located in /sys/class/gpio. However, I failed to found more detailed documentation, most of which only describes plain read/write operation.
What ...
3
votes
1answer
3k views
How to build my very own device tree (and if I need to)
Let me preface this by saying I don't know much about device trees. I do know a bit about ATAGs, since I'm working with this operating system that currently only uses ATAGs.
I'm modifying the ...
0
votes
1answer
508 views
apds 9960 on raspberry pi zero
I would like to use the apds9960 (light/gesture sensor) on rp0 - utilizing the kernel iio driver, which is already available, but there is no dt overlay yet. I guess I need to:
write the dts file
...
0
votes
1answer
2k views
Compile a dts file (dt overlay)
Hello folks maybe I have misunderstood something but I am not sure how to compile my dt overlay file with the etc command (!) I already know that I have to use the @ parameter .
The effect of ...
2
votes
1answer
3k views
How to use BMP280 SPI Kernel Module
I got a adafruit BME280 sensor board and I wired it to the raspberry pi zero via spi. According to the datasheet I can read sensor data from the device via the userspace spi interface. Everything ...
0
votes
1answer
1k views
Disable pull-up resistor on pps-gpio pin
I am using the pps-gpio dtoverlay. My /boot/config.txt has these lines:
# Expect the GPS 1PPS pin to be connected to GPIO3
dtoverlay=pps-gpio,gpiopin=3
Problem is, that the GPS Module (SkyTraq Venus)...
2
votes
1answer
5k views
Missing configuration options on raspi-config screen??? No SPI or Device Tree
Downloaded NOOBS onto my SD card and got my RPi3 up and running.
I'm trying to enable Device Tree and SPI via the advanced options bit on the raspi-config blue screen (so i can install my 3.5inch ...
1
vote
1answer
1k views
How to detect a device tree overlay at run time?
What is the best way to check at run time if a device tree overlay is loaded?
I've found info about checking individual GPIO pin status, and info about how to load the overlay (via config.txt), but I'...
1
vote
2answers
5k views
how to enable spi1? / pi 3 and two rc522 RFID readers
Is it possible to connect two RC522 readers with one RaspberryPi 3?
As far as I know I should just choose different CS pins for them (Add more than 2 SPI slaves).
I have following connections:
1st ...
1
vote
2answers
552 views
Raspberry pi HAT device-tree
I'm currently developping a Raspberry pi HAT. The Raspberry pi HAT must contain a EEPROM with several information in it. This information will be read at boot time in order to configure the Raspberry ...
0
votes
1answer
318 views
device tree and spi controller file
why is the file spi_bcm2708.c is not present inside the path linux/drivers/spi and while inside the boot partition of pi the bcm2708-rpi-version.dts file is only present.how come kernal use the ...
3
votes
1answer
1k views
i2c on a rpi-basic-image created with yocto
I'm attempting to get the i2c bus to work from a raspberry pi image created from yocto. I have looked at other peoples solutions but they are all o do with raspbian or some other flavour of os.
My /...
1
vote
1answer
2k views
unable to install 1-wire temperature sensor
I am trying to figure out why I cannot get temperature sensors working connected to my RPi2. I have followed almost every possible guide on the internets without luck and the answers* provided here ...
4
votes
5answers
5k views
DS18B20 w1-gpio Device Tree gpiopin NOT = 4
I have a HAT which blocks GPIO4 so I cannot use the default pin for the temperature sensor, but I just cannot get it to work on another pin!
I just get lots of 00- instead of 28- in /sys/bus/w1/...
1
vote
0answers
407 views
Setup gpio 23 as shutdown & startup
Followed this tutorial & have included my device tree config below. I've configured my pull up resistor for my button to function properly once my app is running, but I'm curious; is there a way ...
3
votes
1answer
6k views
How to use i2c_gpio with Raspberry Pi?
I would like to use the i2c_gpio software i2c kernel module because the broadcom hardware i2c does not support I2C_M_NOSTART. How do I do this?
I think that in order to do it I need to take the ...
