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by PhilE
Mon Aug 20, 2018 8:34 am
Forum: Compute Module
Topic: Determining via GPIO is the OS has fully shutdown?
Replies: 2
Views: 77

Re: Determining via GPIO is the OS has fully shutdown?

An overlay to enable this feature already exists: [email protected]:~$ dtoverlay -h gpio-poweroff Name: gpio-poweroff Info: Drives a GPIO high or low on poweroff (including halt). Enabling this overlay will prevent the ability to boot by driving GPIO3 low. Usage: dtoverlay=gpio-poweroff,<param>=<val> P...
by PhilE
Fri Aug 17, 2018 7:53 pm
Forum: Device Tree
Topic: "Merge" device tree overlays
Replies: 1
Views: 68

Re: "Merge" device tree overlays

The BCM2835 family of devices only has one I2S interface, so I'm puzzled as to how you would go about having both audio codecs active at the same time. I'm not even sure how the I2S driver will react to two codecs being initialised simultaneously, but at least it should be easy to try, From what I c...
by PhilE
Thu Aug 16, 2018 2:48 pm
Forum: Device Tree
Topic: Devices nodes not created
Replies: 1
Views: 70

Re: Devices nodes not created

It's not immediately obvious why the /dev nodes aren't appearing. It looks as though the necessary call to device_add() should happen as result of the driver calling uart_add_one_port(). If you really want to debug this I would suggest building your own kernel with "#define DEBUG" added to the start...
by PhilE
Thu Aug 16, 2018 12:32 pm
Forum: Compute Module
Topic: CM3L can`t use ttyS0 like console on ubuntu mate
Replies: 3
Views: 76

Re: CM3L can`t use ttyS0 like console on ubuntu mate

I'm happy that your setup is working for you, but there are still a few things I'm not happy about. * "name-overlay.dts" should be compiled to "name.dtbo", not "name-overlay.dtb". The latter will work, but will take slightly longer and produce warnings in the (normally invisible) logs. It also leads...
by PhilE
Thu Aug 16, 2018 10:39 am
Forum: Compute Module
Topic: CM3L can`t use ttyS0 like console on ubuntu mate
Replies: 3
Views: 76

Re: CM3L can`t use ttyS0 like console on ubuntu mate

You have number of problems here: 1) You've hacked the standard uart0 and uart1 overlays to change the default pins and Alt functions. The existing standard overlays have parameters to allow you to achieve what you want to, so use them. 2) You appear to have the alternate function selections confuse...
by PhilE
Tue Jul 31, 2018 6:22 pm
Forum: Device Tree
Topic: Using RTC on CM GPIO 0 and 1
Replies: 4
Views: 134

Re: Using RTC on CM GPIO 0 and 1

1. Download the source to the standard overlay from here . 2. Change all occurrences of &i2c_arm to &i2c0, and save it as i2c0-rtc-overlay.dts. 3. Compile and install the new overlay with: $ dtc [email protected] -I dts -O dtb -o i2c0-rtc.dtbo i2c0-rtc-overlay.dts $ sudo cp i2c0-rtc.dtbo /boot/overlays 4. Use with...
by PhilE
Tue Jul 31, 2018 5:39 pm
Forum: Device Tree
Topic: Using RTC on CM GPIO 0 and 1
Replies: 4
Views: 134

Re: Using RTC on CM GPIO 0 and 1

It is unclear from your post how many overlays you have now accumulated - please post the contents of config.txt (or at least the settings you have changed) - I suspect there may be a clash for pin usage. It is also unclear if you understand that i2c-gpio is a bit-bashed/software I2C bus - have you ...
by PhilE
Mon Jul 30, 2018 6:14 am
Forum: Device Tree
Topic: GPIO - SMI pulldown
Replies: 3
Views: 167

Re: GPIO - SMI pulldown

The pulls are independent of the alt functions, but they are also weak (around 50kOhm). If the pin has to be low then or should be driven low, either through the alt function (whatever it may be) or as a GPIO output.
by PhilE
Sat Jul 28, 2018 11:17 am
Forum: Compute Module
Topic: Compute Module I2C not working (I2Cdetect)
Replies: 21
Views: 3165

Re: Compute Module I2C not working (I2Cdetect)

From memory, the Compute Modules don't have built in pull-ups on the I2C lines. Try adding external pull-up resistors, as required by I2C, and see if that makes a difference.
by PhilE
Mon Jul 23, 2018 3:33 pm
Forum: Troubleshooting
Topic: Pi 3 B+ eth0 MAC Address Change Fails
Replies: 9
Views: 663

Re: Pi 3 B+ eth0 MAC Address Change Fails

The journalctl log only seems to show the failure to get an IP address - do you have one for successfully getting one? Ideally it would show the initial success with the default MAC address, then the failure after changing it, then the success after reverting to the default. You could also look for ...
by PhilE
Sat Jul 21, 2018 6:46 pm
Forum: Advanced users
Topic: Filesystem for Honeypot
Replies: 11
Views: 506

Re: Filesystem for Honeypot

Moved to Advanced Users - a more natural home.

liquizzell - although the advice may not have been what your were hoping for, you would be wise to think carefully before opening your system up to invaders.
by PhilE
Thu Jul 19, 2018 9:38 am
Forum: Advanced users
Topic: New experimental GL driver configuration
Replies: 15
Views: 13192

Re: New experimental GL driver configuration

As Gavinmc42 said, use raspi-config to enable the VC4 driver.
by PhilE
Thu Jul 19, 2018 9:36 am
Forum: Add-ons
Topic: Looking for Driver RTL8812BU for RPI 3B+
Replies: 5
Views: 288

Re: Looking for Driver RTL8812BU for RPI 3B+

MrEngman's set of out-of-tree WiFi driver builds includes the RTL8812au, which may work. See these instructions for how to download them: viewtopic.php?t=178405
by PhilE
Thu Jul 19, 2018 9:29 am
Forum: Add-ons
Topic: Looking for Driver RTL8812BU for RPI 3B+
Replies: 5
Views: 288

Re: Looking for Driver RTL8812BU for RPI 3B+

Moved to Add-ons - the adaptor is a USB device so Device Tree should be irrelevant.
by PhilE
Tue Jul 17, 2018 4:18 pm
Forum: Compute Module
Topic: Help getting DPI touchscreen to work on Compute Module 3
Replies: 7
Views: 314

Re: Help getting DPI touchscreen to work on Compute Module 3

Problem 1: Either you don't have the i2c_dev module loaded, or you don't have any enabled I2C buses or both. Running lsmod will tell you if i2c_dev is loaded - if not, "sudo modprobe i2c_dev" and "ls /dev/i2c*". Problem 2: Your overlay changes the pins claimed on behalf of i2c1, but sets the pin fun...
by PhilE
Tue Jul 17, 2018 3:18 pm
Forum: Compute Module
Topic: Help getting DPI touchscreen to work on Compute Module 3
Replies: 7
Views: 314

Re: Help getting DPI touchscreen to work on Compute Module 3

The official Raspberry Pi touchscreen lives on I2C0, which is reserved for the firmware on most Pis, and is polled by the firmware; the kernel driver retrieves the touch event data from the firmware, not from I2C. Let's go back to basics. What do the following commands return? $ i2cdetect -y 0 $ i2c...
by PhilE
Mon Jul 16, 2018 10:40 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 10
Views: 548

Re: Connecting external raw nand using GPIO - RPI3b

The GPIO alternate function assignments are listed on page 102 of the BCM2835 ARM Peripherals guide.
by PhilE
Mon Jul 16, 2018 10:00 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 10
Views: 548

Re: Connecting external raw nand using GPIO - RPI3b

The post is a bit ambiguous, but the smi-nand overlay (at least as it is now) is standalone. I don't know whether the SMI interface can multiplex address and data on the same lines - that's clearly not the way this overlay is expected to be used. I've pinged LukeW, the author of the driver, in case ...
by PhilE
Mon Jul 16, 2018 8:39 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 10
Views: 548

Re: Connecting external raw nand using GPIO - RPI3b

I have been only dimly aware of SMI - I've used I2C, SPI, SD, but not SMI - so when you mentioned NAND I didn't immediately think of it. But yes - the BCM2835 has an SMI interface, and there is a driver and overlay for it in the RPi kernel trees. There is also a NAND adaptation layer driver and over...
by PhilE
Fri Jul 13, 2018 3:24 pm
Forum: Compute Module
Topic: [SOLVED] PWM0 on GPIO40 - can't export due to permissions?
Replies: 2
Views: 165

Re: PWM0 on GPIO40 - can't export due to permissions?

I think your use of sudo is ineffective because of the way shell redirection works. When you write: $ sudo echo 0 > export the shell splits the line at the '>' and passes everthing on the left to sudo, redirecting the output to 'export'. That sounds okay, except that the sudo command and the file ac...
by PhilE
Fri Jul 13, 2018 6:40 am
Forum: Compute Module
Topic: CM3 eMMC with u-boot not working
Replies: 4
Views: 282

Re: CM3 eMMC with u-boot not working

There should be no doubt - BCM2837 is a 64-bit capable SoC, but the standard Raspberry Pi kernel runs in 32-bit mode. While there are some nice aspects of going 64-bit, there is no clear performance benefit to justify supporting a third kernel variant. Other distributions are available that are buil...
by PhilE
Thu Jul 12, 2018 2:02 pm
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 10
Views: 548

Re: Connecting external raw nand using GPIO - RPI3b

The exact form of a gpio declaration is system-specific. But the first term is a reference to a label in the Device Tree, where the label is meant to be attached to a GPIO controller. On Raspberry Pi devices the main user-accessible GPIOs (the ones on the 40-pin header) are provided by a DT node wit...
by PhilE
Thu Jul 12, 2018 1:33 pm
Forum: Device Tree
Topic: DT bcm watchdog - I can load it but can I start it?
Replies: 2
Views: 203

Re: DT bcm watchdog - I can load it but can I start it?

In short, no. Although the firmware is loading and manipulating the Device Tree, (with a few exceptions) only Linux is acting on it, so you are effectively asking if we can configure Linux to start the watchdog timer in case Linux doesn't load correctly. That's not as stupid as it sounds - the watch...
by PhilE
Wed Jul 11, 2018 3:41 pm
Forum: Compute Module
Topic: CM3 using DPI, I2C and SPI
Replies: 6
Views: 332

Re: CM3 using DPI, I2C and SPI

No, Device Tree isn't that hard. There are lots of example overlays in the kernel tree: https://github.com/raspberrypi/linux/tree/rpi-4.14.y/arch/arm/boot/dts/overlays There is also a utility called ovmerge (available here: https://github.com/raspberrypi/utils/blob/master/ovmerge/ovmerge) that appli...

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