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by PhilE
Thu Jan 18, 2018 9:13 pm
Forum: Compute Module
Topic: CM3 SDIO WiFi and eMMC
Replies: 1
Views: 8

Re: CM3 SDIO WiFi and eMMC

There are two SD controllers and (from memory), at least 3 pin mappings. SDIO devices such as WiFi must use the Arasan MMC controller, leaving the Broadcom SDHOST controller to run the SD card.
by PhilE
Thu Jan 18, 2018 5:11 pm
Forum: Compute Module
Topic: Additional SD Card on CM3
Replies: 1
Views: 20

Re: Additional SD Card on CM3

This question has been asked before in various forms - see viewtopic.php?f=98&t=194739.
by PhilE
Wed Jan 17, 2018 9:43 pm
Forum: Compute Module
Topic: Both UARTs enabled + serial (Linux) console on UART1. How to?
Replies: 1
Views: 52

Re: Both UARTs enabled + serial (Linux) console on UART1. How to?

You can enable UART1 and map it to GPIOs 32 and 33 by adding the following to /boot/config.txt:

Code: Select all

dtoverlay=uart1,txd1_pin=32,rxd1_pin=33
To create a linux console on UART1 (ttyS0), add "console=ttyS0,115200" to /boot/cmdline.txt.
by PhilE
Wed Jan 17, 2018 2:53 pm
Forum: Compute Module
Topic: Please help to Remap pin Uart 0
Replies: 9
Views: 234

Re: Please help to Remap pin Uart 0

Yes, pretty much. The overlay is intended for use on a Compute Module, where there are more pins available for user applications. There is more information in the README: pi@raspberrypi:~$ dtoverlay -h uart0 Name: uart0 Info: Change the pin usage of uart0 Usage: dtoverlay=uart0,<param>=<val> Params:...
by PhilE
Wed Jan 17, 2018 1:46 pm
Forum: Compute Module
Topic: Please help to Remap pin Uart 0
Replies: 9
Views: 234

Re: Please help to Remap pin Uart 0

Unfortunately your scheme won't work. There is only one set of pins brought out onto the 40-pin header that can carry the UART signals - GPIOs 14-17 (TXD, RXD, CTS & RTS). These signals can be from UART0 (ttyAMA0) or UART1 (ttyS0), but not both. You need to read page 102 of the BCM2835 ARM Periphera...
by PhilE
Fri Jan 12, 2018 11:11 am
Forum: Compute Module
Topic: Raspberry Pi Compute Module 3 … Super-Computer
Replies: 3
Views: 122

Re: Raspberry Pi Compute Module 3 … Super-Computer

Cool - I missed that thread.
by PhilE
Fri Jan 12, 2018 10:34 am
Forum: Compute Module
Topic: Raspberry Pi Compute Module 3 … Super-Computer
Replies: 3
Views: 122

Re: Raspberry Pi Compute Module 3 … Super-Computer

The stumbling block in thought experiments like this is always the interconnect. Supercomputers need high-speed links between the nodes, and BCM2837 doesn't give you many options - and none of them really fit the bill of any-to-any links and high performance. You could perhaps theoretically use CSI/...
by PhilE
Fri Jan 12, 2018 9:30 am
Forum: Compute Module
Topic: Please help to Remap pin Uart 0
Replies: 9
Views: 234

Re: Please help to Remap pin Uart 0

That overlay will be part of the next firmware release, although I did remove the rts and cts pin parameters because they didn't work properly.
by PhilE
Thu Jan 11, 2018 10:13 am
Forum: Compute Module
Topic: Please help to Remap pin Uart 0
Replies: 9
Views: 234

Re: Please help to Remap pin Uart 0

As you've discovered, there is no standard uart0 overlay, but there should be. Copy this code into a file called uart0-overlay.dts: /dts-v1/; /plugin/; /{ compatible = "brcm,bcm2708"; fragment@0 { target = <&uart0>; __overlay__ { pinctrl-names = "default"; pinctrl-0 = <&uart0_pins>; status = "okay";...
by PhilE
Sun Jan 07, 2018 9:50 pm
Forum: Device Tree
Topic: Confirmation of gpio-poweroff Behavior
Replies: 4
Views: 208

Re: Confirmation of gpio-poweroff Behavior

My boot sequence is particularly slow because kernel UART output is enabled and it is running from an NFS-mounted root FS, but that should not alter the final shutdown sequence. At the end of the power-down the gpio-poweroff driver sets the pin active (low) for 100ms, then inactive (high) for 100ms,...
by PhilE
Fri Jan 05, 2018 10:14 am
Forum: Device Tree
Topic: Confirmation of gpio-poweroff Behavior
Replies: 4
Views: 208

Re: Confirmation of gpio-poweroff Behavior

Running the same tests I get different results - it works as expected. First without the dt-blob: without_dtblob.png Then with: with_dtblob.png Apart from a decrease in the time before GPIO21 goes high, the two traces are essentially the same. My advice is to work with the natural pull of the GPIO (...
by PhilE
Wed Dec 20, 2017 11:02 am
Forum: Compute Module
Topic: [SOLVED] eMMC not mounting after rpiboot
Replies: 6
Views: 528

Re: eMMC not mounting after rpiboot

Thanks for the feedback. Let us know if there are any new developments, but we'll consider this matter closed for now.
by PhilE
Mon Dec 18, 2017 3:07 pm
Forum: Device Tree
Topic: Bluetooth does not find adaptor after overlay=pi3-miniuart-bt
Replies: 2
Views: 256

Re: Bluetooth does not find adaptor after overlay=pi3-miniuart-bt

By the way, you shouldn't have to disable the systemd getty service because it takes its cue from the kernel command line; removing "console=serial0,..." should be sufficient.
by PhilE
Mon Dec 18, 2017 3:04 pm
Forum: Device Tree
Topic: Bluetooth does not find adaptor after overlay=pi3-miniuart-bt
Replies: 2
Views: 256

Re: Bluetooth does not find adaptor after overlay=pi3-miniuart-bt

1. What is in /lib/systemd/system/hciuart.service?
2. Does /usr/bin/btuart exist?
3. What do get from running "ls -l /dev/serial*"?
by PhilE
Mon Dec 18, 2017 9:22 am
Forum: Device Tree
Topic: using mcp23s17 device tree with gpio-leds
Replies: 5
Views: 374

Re: using mcp23s17 device tree with gpio-leds

Ah, you've discovered the 80 character line limit for config.txt entries. Fortunately there is workaround. Parameters that appear as part of the dtoverlay line are treated exactly the same as subsequent dtparam lines. The point where the overlay content is finalised and the parameters go out of scop...
by PhilE
Fri Dec 15, 2017 10:57 am
Forum: Compute Module
Topic: uSDCard can't mount after Boot Raspi over USB
Replies: 8
Views: 429

Re: uSDCard can't mount after Boot Raspi over USB

You can use the GPIO sysfs interface , or the relatively new IOCTL API (examples here: https://github.com/torvalds/linux/tree/ ... tools/gpio).

If you want existing command line utilities you can script there are currently raspi-gpio, wiringpi, pigpio etc.
by PhilE
Fri Dec 15, 2017 9:44 am
Forum: Compute Module
Topic: SD card license for 4-bit SD mode
Replies: 4
Views: 364

Re: SD card license for 4-bit SD mode

I am not a lawyer, and you may want to ask one, but my understanding is that a licence is not necessary. This is some of the wording on the SD Association website: In order to manufacture and sell Host/Ancillary Products, a prospective licensee may obtain the rights to the essential patents, tradema...
by PhilE
Mon Dec 11, 2017 9:54 pm
Forum: C/C++
Topic: [SOLVED] Writing a codec driver
Replies: 33
Views: 1638

Re: [SOLVED] Writing a codec driver

Your captures do appear to fade in - this is particulary obvious on the sine wave. It's worth checking that the fade in isn't in the source file.
by PhilE
Mon Dec 11, 2017 9:25 pm
Forum: C/C++
Topic: [SOLVED] Writing a codec driver
Replies: 33
Views: 1638

Re: Writing a codec driver

Don't be angry - be happy you have a working device. :D
by PhilE
Mon Dec 11, 2017 9:20 pm
Forum: C/C++
Topic: [SOLVED] Writing a codec driver
Replies: 33
Views: 1638

Re: Writing a codec driver

Since changing the size of the window dramatically alters the artifacts, and in this case a small window actually gives the best results, I'm tempted to say that the audio is good and that the problem is with the tools and our ability to use them.
by PhilE
Mon Dec 11, 2017 9:06 pm
Forum: C/C++
Topic: [SOLVED] Writing a codec driver
Replies: 33
Views: 1638

Re: Writing a codec driver

Does that mean we can effectively close this thread? With enough buffering you don't get underrun, and 16-bit captures show that the waveform looks good - remember to use a large window with a frequency plot if you want to avoid spurious odd-looking frequency spikes.
by PhilE
Mon Dec 11, 2017 8:43 pm
Forum: C/C++
Topic: [SOLVED] Writing a codec driver
Replies: 33
Views: 1638

Re: Writing a codec driver

The reason the clip looks and sounds so strange is that it appears to contain 24-bit samples packed into 32-bit words with no sign extension, and the location of the padding zero makes it look strange when the samples are interpreted as 32-bit values. If you insert a single zero byte at offset 44 in...
by PhilE
Mon Dec 11, 2017 4:02 pm
Forum: Device Tree
Topic: [Custom Kernel] after compilation dtb modules are missing
Replies: 17
Views: 2655

Re: [Custom Kernel] after compilation dtb modules are missing

Yes, I get the same now, having allowed the build to run to completion. It looks like merging two sets of patches - ours again upstream, mptcp against upstream - is problematic. I've tried several different merge orders with no luck, so I suggest you try the following: 1. Take a copy of the working ...
by PhilE
Mon Dec 11, 2017 3:35 pm
Forum: Device Tree
Topic: using mcp23s17 device tree with gpio-leds
Replies: 5
Views: 374

Re: using mcp23s17 device tree with gpio-leds

The overlay looks OK to me - it compiles, but I haven't used it - except for one thing: the "labele" property should say "label".
by PhilE
Mon Dec 11, 2017 11:49 am
Forum: C/C++
Topic: [SOLVED] Writing a codec driver
Replies: 33
Views: 1638

Re: Writing a codec driver

Reading your answers this seems more like a sampling or analysis (windowing?) problem than a real problem in the datastream.

Can you make a capture available somewhere to download?

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