Raspberry Pi 3 und EnOcean Pi - Kompatibilitätsproblem

Question

Als diese Woche der neue RPi3 rauskam, waren wir voller Ehrgeiz, künftig in unseren Systemen zu switchen.

Immerhin würde der RPi3 es ermöglichen auf einen USB Bluetooth Dongle zu verzichten und eine WiFi-Connectivity macht die Verbindung zu unseren Servern noch einfacher .

leider weit gefeht, denn das ganze funkt nur unter Verwendung der SDIOs und UART (durch Aktivierung der Devce Tree-Funktionwn, was dann jedoch den EnOceanPi, der ebenfalls /dev/ttyAMA0 (UART) verwendet, außer Betrieb setzt. Sprich, wir haben es noch nicht geschafft, EnOceanPi, WiFi und Bluetooth am RPi3 zum Laufen zu bringen.

Hat wer, der mehr Erfahrung mit HW-orientierter Programmierung hat eine Idee?

fvan · Answer

You're right! I rolled back the changes from Brian's procedure and restored all files. Then: - Make sure everything is up-to-date: sudo apt-get update && sudo apt-get upgrade && sudo rpi-update (I think rpi-update did the trick for me) - Enable Serial via raspi-config, but edit /boot/cmdline.txt to disable serial console - Use /dev/ttyS0 instead of /dev/ttyAMA0 - Reboot Data is now coming in OpenHab via EnOceanPi and EnOcean binding:

shabaz · Answer

(overall summary)

It appears, there are a few options, and as usual the information is splattered all over the place since raspberrypi.org use their forum comments as documentation, and so people have to read dozens (sometimes hundreds) of comments to understand the changes, since the first few comments are invariably wrong or have outdated information. And others have written blog posts all over the place, and many are outdated since the information has changed in releases and some people don't go back and edit their posts and mark the changes..

I have tried to summarize. It could be wrong too. If it is, please let me know and I will edit this post and label it as edited. Once it is fleshed out, if people prefer, I'll write it up as a blog post/document when can have revisions and can have user comments, but the blog post ends up being the first thing read. So reduces the confusion.

As far as I can tell, this is the latest information, these apply to recent software images only.

Main issue: There are two serial interfaces on the Broadcom chip that the Pi uses. One works fine, the other has a speed dependent on the core clock speed. The core clock speed is usually dynamic and changes on the fly. When the core clock speed is high, the CPU performance can be high.

One serial interface goes to Bluetooth, the other goes to the 40-pin connector. Which one goes where? That is selectable at boot; the Broadcom chip can internally reroute it. By default, the varying one goes to the 40-pin connector and that is clearly a problem if you wish to make use of it in any way.

There are 4 options:

Option 1. Have the serial interface (UART) functioning correctly, but no Bluetooth capability

--> Swap the UARTs around. To do this, add the following to /boot/config.txt: dtoverlay=pi3-disable-bt dtoverlay=pi3-miniuart-bt

and type the following to disable the Bluetooth (since it is now on the changeable speed UART): sudo systemctl disable hciuart

Option 2. Have the serial interface functioning and have Bluetooth functioning very well, but have the clock speed of the processor fixed (to a low speed [250MHz] or a high speed [500MHz?])

--> Add the following to /boot/config.txt: enable_uart=1

It will affect the CPU performance because it controls the speed of the L2 cache, and will reduce the analog audio quality (references are here and here respectively)

For the high clock speed (which will require a fan and heatsink realistically) to get back the CPU perf and audio quality, also add the following to the same file: force_turbo=1

Option 3. Have a broken serial interface (varying speed) but have Bluetooth capability

--> Do nothing. This is the default setting

Option 4: Have the serial interface (UART) functioning correctly, also have Bluetooth working but slowly

--> Swap the UARTs around. To do this, add the following to /boot/config.txt: dtoverlay=pi3-miniuart-bt

and then set the core frequency to a low, fixed value by adding the following to /boot/config.txt: core_freq=250. It will affect the CPU performance. If you want

higher performance then do not add the core_freq=250 line and instead have the line force_turbo=1 but this requires a fan and heatsink.

The serial interface (i.e. UART) can be used for HATs/hardware etc., or can be used with a USB-Serial adapter to access a Linux shell (also known as a console session) using a PC and PuTTY, and it also dumps out startup text during boot. If you've got hardware connected (like Enocean Pi) then you don't want that startup text output during boot or Linux shell access because the hardware will be like "what was that?!" when it sees it.

For options 1 or 2 or 4, if you want the console session on the UART (i.e. you don't have hardware connected and just want to connect your USB-Serial to your PC and see the Linux shell), ensure you have the following in the text line within the file /boot/cmdline.txt:

console=serial0,115200

That line should be there by default.

If you have hardware connected that needs the serial port then remove the text console=serial0,115200

Is this understanding correct (looking at the Pi experts to help here like rew to keep me honest..)?

shabaz · Answer

Generally, (not specific to this issue) do you have a USB-to-serial adapter? They are extremely useful for accessing via serial. If you don't have one, it is highly recommended. With that you'd be able to test the serial interface. You can buy them or even build one, the link here lists both options: Building a USB UART Serial Adapter

cstanton · Answer

Because when you're disabling the device tree you're disabling all of the configuration settings that make the Pi 3 work with the GPIO mappings to be setup as they should be. As usual make sure your Raspbian is up to date with apt-get and firmware with rpi-update. Not using the device tree will change more settings than just that of the UART mapping. So it looks like this may be fixed in the next firmware update for the pi.

mcb1 · Answer

Robert We did a design challenge using EnOcean and Raspberry Pi. Forget Me Not Design Challenge fvan Frederick did some work with external serial, and there may be a solution there by simply repointing it. I'm interested in suing using the Pi3 for this, as the original was lacking a little for the amount of data we collected and graphed. Mark edit due to a minor spelling error kindly pointed out by a very observant reader.....

fvan · Answer

Made a blog post on how to get the UART to work from scratch: UART for Serial Console or HAT on Raspberry Pi 3 – Frederick Vandenbosch

shabaz · Answer

Hi Adriano, What is the content of your /boot/cmdline.txt file? Could you paste it? Has the console=serialx,115200 line portion of it been deleted? It may be something else with an older image, but will be in the format console=xxx,115200

robertheinze · Answer

Brian did some testing with reassigning the BT, but I had no time for testing so far. Would be interesting whether this helps ... Brian Dorey.com | Raspberry Pi 3 UART Overlay Workaround

fvan · Answer

Another possibility is to use the USB dongle instead of the EnOceanPi, doing serial via USB.

cstanton · Answer

Has the latest firmware not fixed these problems?