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by bbear20210615
Sat Apr 02, 2022 8:06 am
Forum: Troubleshooting
Topic: issue with using the dtoverlay of fbtft
Replies: 0
Views: 60

issue with using the dtoverlay of fbtft

I am trying to use the 4inch RPi LCD(A) ( https://www.waveshare.com/4inch-rpi-lcd-a.htm ) from waveshare. And I use the raspberry pi zero 2. I can light the LCD successfully with the following config in /boot/config.txt: dtoverlay=fbtft,spi0-0,piscreen,reset_pin=25,dc_pin=24 dtoverlay=ads7846,penirq...
by bbear20210615
Mon Nov 29, 2021 1:26 am
Forum: General discussion
Topic: RPI OS desktop can't rotate with xorg.conf
Replies: 2
Views: 344

Re: RPI OS desktop can't rotate with xorg.conf

Can you rotate it when using Screen configuration editor or via xrandr command? What's the content of '/usr/share/dispsetup.sh'? Which display do you use on DSI-1 as you have 720x1280pixel resolution? Thanks you for your reply. I tried to rotate the lcd display with the xrandr command: DISPLAY=:0 x...
by bbear20210615
Fri Nov 26, 2021 8:15 am
Forum: General discussion
Topic: RPI OS desktop can't rotate with xorg.conf
Replies: 2
Views: 344

RPI OS desktop can't rotate with xorg.conf

I used to rotate my desktop with the configuration of xorg.conf. I add my config file 10-disp.conf into /usr/share/X11/xorg.conf.d/ detail of 10-disp.conf Section "Monitor" Identifier "DSI-1" Option "Rotate" "right" Option "Primary" "on" En...
by bbear20210615
Thu Nov 18, 2021 1:57 am
Forum: Compute Module
Topic: CM4 can't work with wm8960 with original RPI OS driver
Replies: 4
Views: 283

Re: CM4 can't work with wm8960 with original RPI OS driver

This page covers the subject quite well: https://superuser.com/questions/53957/what-do-alsa-devices-like-hw0-0-mean-how-do-i-figure-out-which-to-use You might also learn something from this: https://programmer.group/stm32mp157-wm8960-audio-driver-debugging-notes.html In your case it looks as though...
by bbear20210615
Wed Nov 17, 2021 2:06 am
Forum: Compute Module
Topic: CM4 can't work with wm8960 with original RPI OS driver
Replies: 4
Views: 283

Re: CM4 can't work with wm8960 with original RPI OS driver

It would help if you explain what you have tried so far, if anything. Thank you for your reply. I first tried to add dtoverlay=wm8960-soundcard into /boot/config.txt after I reboot. I can find the wm8960 device with command aplay -l and arecord -l pi@raspberrypi:~ $ aplay -l **** List of PLAYBACK H...
by bbear20210615
Tue Nov 16, 2021 10:36 am
Forum: Compute Module
Topic: CM4 can't work with wm8960 with original RPI OS driver
Replies: 4
Views: 283

CM4 can't work with wm8960 with original RPI OS driver

Hello. I am working on my CM4 board with my own customized carry board. I have wm8960 on my customized board. I have tried driver from seeed https://github.com/respeaker/seeed-voicecard It works fine. However, it don't use the original RPI kernel driver of wm8960. How can I get my wm8960 working fin...
by bbear20210615
Fri Nov 12, 2021 10:28 am
Forum: Compute Module
Topic: Use uart3 to send and receive date via a rs485 module
Replies: 8
Views: 583

Re: Use uart3 to send and receive date via a rs485 module

May I suggest that you look at the PoE Compute Module 4 IO Board (type B) made by Waveshare? They published the schematics in their WIKI and the board has a working RS-485 circuit connected to UART 5, along with a working RS232 circuit connected to UART 3. You can operate RS-485 with just the trans...
by bbear20210615
Fri Nov 12, 2021 10:15 am
Forum: Compute Module
Topic: Use uart3 to send and receive date via a rs485 module
Replies: 8
Views: 583

Re: Use uart3 to send and receive data via a rs485 module

Thank you for your reply.I think I have a idea of fixing this problem. I use the GPIO7 to replace the GPIO25. And then set GPIO7 function to alt4.So it's RTS3 now. The default level of RTS3 is high. and when UART3 is sending data.RTS3 is low. When GPIO7 is connect to TP485E. if CM4 want to send dat...
by bbear20210615
Fri Nov 05, 2021 2:57 am
Forum: Compute Module
Topic: Use uart3 to send and receive date via a rs485 module
Replies: 8
Views: 583

Re: Use uart3 to send and receive data via a rs485 module

Thank you for your reply.I think I have a idea of fixing this problem. I use the GPIO7 to replace the GPIO25. And then set GPIO7 function to alt4.So it's RTS3 now. The default level of RTS3 is high. and when UART3 is sending data.RTS3 is low. When GPIO7 is connect to TP485E. if CM4 want to send dat...
by bbear20210615
Wed Nov 03, 2021 2:44 am
Forum: Compute Module
Topic: Use uart3 to send and receive date via a rs485 module
Replies: 8
Views: 583

Re: Use uart3 to send and receive date via a rs485 module

Don't think the standard kernel supports RS-485 mode on the pl011 UARTs used on the pi - see this thread . You might need to roll your own kernel, as danjperron suggests. Thank you for your reply.I think I have a idea of fixing this problem. I use the GPIO7 to replace the GPIO25. And then set GPIO7...
by bbear20210615
Tue Nov 02, 2021 8:12 am
Forum: Compute Module
Topic: Use uart3 to send and receive date via a rs485 module
Replies: 8
Views: 583

Re: Use uart3 to send and receive date via a rs485 module

One more thins:
When I set the GPIO25 to high. The pc can get the data from CM4.
by bbear20210615
Tue Nov 02, 2021 8:08 am
Forum: Compute Module
Topic: Use uart3 to send and receive date via a rs485 module
Replies: 8
Views: 583

Use uart3 to send and receive date via a rs485 module

Hello. I am work on my CM4 with a rs485 chip(TP485E). I use the uart3 and GPIO25 to connect to the rs485 chip. And I tried to add my dtoverlay(base on uart3-overlay.dts) to the system. here is the dtoverlay code: /dts-v1/; /plugin/; /{ compatible = "brcm,bcm2711"; fragment@0 { target = <&a...
by bbear20210615
Tue Oct 26, 2021 2:43 am
Forum: Device Tree
Topic: how to use dtparam to overwrite the string in Angle brackets(<>)
Replies: 5
Views: 668

Re: how to use dtparam to overwrite the string in Angle brackets(<>)

There are two ways to set a property to a specific phandle (a reference to a label on a node, e.g. "&input_pins") based a parameter: 1. Create a disabled (__dormant__) fragment targeting the node containing the property and its new value. Make the parameter an overlay-level (as oppose...
by bbear20210615
Mon Oct 25, 2021 2:56 am
Forum: Device Tree
Topic: how to use dtparam to overwrite the string in Angle brackets(<>)
Replies: 5
Views: 668

Re: how to use dtparam to overwrite the string in Angle brackets(<>)

What you are asking for is not possible, but there may be another way to achieve the same goal. How many different values of the pinctrl-0 property do you need to support? Can you list them all ahead of time so that they can be built into the overlay? Don't worry about how yet - I can help with tha...
by bbear20210615
Sat Oct 23, 2021 12:46 pm
Forum: Device Tree
Topic: how to use dtparam to overwrite the string in Angle brackets(<>)
Replies: 5
Views: 668

how to use dtparam to overwrite the string in Angle brackets(<>)

I am working on my dtoverlay now. In order to fix a Compatibility issues. I want to overwrite a string in a Angle brackets. fragment@7 { target-path="/"; __overlay__ { gpio_keys { compatible = "gpio-keys"; pinctrl-names = "default"; pinctrl-0 = <>; status = "okay&q...
by bbear20210615
Mon Aug 02, 2021 1:59 am
Forum: Graphics programming
Topic: PYQT and yocto without x11
Replies: 5
Views: 2651

Re: PYQT and yocto without x11

The error log said that you qt demo can't connect to the display.
And you display client is XCB.You can check if your machine have the display server by "echo $DISPLAY".
If not, you should add the server like x11-server into your image.
by bbear20210615
Tue Jul 06, 2021 11:15 am
Forum: General discussion
Topic: Raspberry Pi CM4 kernel driver loading sequence
Replies: 0
Views: 100

Raspberry Pi CM4 kernel driver loading sequence

Is there any way that I can find out the kernel driver loading sequence of the CM4?

I will appreciate that if someone could help me~
Thanks~
by bbear20210615
Fri Jun 18, 2021 9:35 am
Forum: Compute Module
Topic: Raspberry Pi Compute Module 4 question with Bluetooth Add Device...
Replies: 0
Views: 567

Raspberry Pi Compute Module 4 question with Bluetooth Add Device...

I use my Raspberry Pi Compute Module 4(CM4) with the Raspberry Pi Compute Module 4 IO Board. When I power on the board and use the VNC to control the Destop of CM4. The bluetooth is turned on by default. I click the bluetooth icon on the right top of the desktop.Then click the button "Add Devic...

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