Access Point (hotspot mode) Running At 5GHz on the PXFmini-RaspberryPiZeroW Autopilot

jackemoore (Jack Moore) 2017-11-03 15:48:20 UTC #1

Hi Everyone,
I have a number of questions that I'm hoping to receive some answers and/or clarifications.

Question #1: Has anyone been successful in getting the Access Point (Hotspot mode) running at 5Ghz with the PXFmini-RaspberryPiZeroW autopilot? If so, I'd appreciate receiving details on how to properly configure the autopilot.

Question #2: I'm using the OS Image PXFmini-RasperryPiZeroW-29-04-2017.img. Is there a newer recommended version available?

I'm trying to use the Edimax EW-7811UTC AC600 external 802.11ac WiFi adapter that is recommended and supplied by erle-robotics for handling the 5GHz Access Point (Hotpoint mode) objective.

Question #3a: Is the recommended software driver already installed in the 29-04-2017 OS Image for handling the external Edimax AC600 USB WiFi adapter with the PXFmini-RaspberryPiZeroW autopilot?

Question #3b: Is “rt1871xdrv” the recommended software driver for the Edimax AC600?

Question #3c: When editing /etc/hostapd/hostapd.conf to remove the # from #driver=rt1871xdrv, why does the autopilot report “unknown driver”?

Question #4: When configuring the autopilot to use the internal WiFi adapter for Client (Managed) mode on the wlan0 interface and the Edimax external WiFi adapter for Access Point mode on the wlan1 interface, why does the autopilot report the following messages for wlan1? “not configured”, “could not configure driver mode”, “driver initialization failed”, and “iwconfig” shows for wlan1: “unassociated”, “mode:Auto” (not “mode:Master”), and “Access Point: Not Associated”. Within /etc/hostapd/hostapd.conf the defaults #driver=rt1871xdrv” and “#driver=n180211” are left as is.

I have used the HomeSpot 150 Mbps Wireless USB Adapter in place of the Edimax AC600 and it appears to both associate and configure correctly. I see the hotspot “erle-robotics-frambuesa” appear on my laptop wireless network connection. However, attempting to make a connection fails and it appears data packets are not being sent by the autopilot.

Question #5: When using an external WiFi adapter for Access Point mode on the wlan1 interface, where are all the places in the software that the default wlan0 needs to be reconfigured to wlan1? I have already taken care of “/etc/network/interfaces”, “/etc/hostapd/hostapd.conf”, “/etc/dnsmasq.conf”, and “/etc/wpa_supplicant/wpa_supplicant.conf”.

The wlan0 interface appears to work correctly in Client mode and successfully connects to my internet wireless router.

Before attempting to switch WiFi modes within the autopilot software, the default configurations for wlan0 interface setup for Access Point mode, wlan1 interface setup for Client mode and attaching the recommended Edimax AC600 WiFi adapter, I have been successful in simultaneously connecting wireless to the ArduPilot Mission Planner V1.3.50 on my laptop and the internet via my wireless router. Installed in my autopilot is ArduCopterHexa V3.5.3. I was also able to connect to the Mission Planner after substituting the HomeSpot Wireless Adapter in place of the Edimax AC600 adapter. Both adapters worked well connecting to the internet at 2.4 GHz bandwidth. The PXFmini shield I purchased is the latest revision with the new JST CH connectors. Also, attached to the Raspberry Pi Zero W is an OTG USB Hub with Logitech Keyboard & Mouse and Hdmi 5 Inch Capacitive Touch Screen.

With your help, I hope to reconfigure the autopilot to handle Access Point mode at 5GHz bandwidth and higher WiFi speeds.

LanderU (Lander Usategui) 2017-11-06 08:54:27 UTC #2

Hi @jackemoore,

With internal WiFi is not possible.

No.

Yes, is already compiled in your system. You can check it using lsmod | grep 8812au.

We're using this one: https://github.com/gnab/rtl8812au

Could you please share with us a picture/video?

Same than above.

Are you using Windows? You can set manually the ip address if you've connection problems.

Yes, if you need use two interfaces. If you only need the external one you can disable the internal WiFi, and no changes are required.

Regards,

@LanderU

jackemoore (Jack Moore) 2017-11-09 01:26:50 UTC #3

Hi @LanderU,
I have a few more questions that I'm hoping to receive some answers and/or clarifications.

Revisit Question #1: Your original answer was: “With internal WiFi it is not possible”. I understand the built-in WiFi only supports 2.4GHz bandwidth. What would be your answer to Question #1 if the Edimax AC 600 USB is mounted?

Revisit Question #3a: Using lsmod, it shows 8812au is included. Is the proper name for the driver “rtl871zdrv” ? If not, what is the proper name?

Revisit Question #3c: Removing the comment prefix # from #driver=rt1871xdrv” within hostapd.conf, then reboot, and using sudo hostapd -B /etc/hostapd/hostapd.conf, this results in showing the message “Line 19: invalid/unknown driver 'rtl871zdrv'.

Question #3d: Is hostapd built with the 8812au driver support?

When the internal WiFi is disabled using blacklist, the Edimax AC 600 USB is mounted, and no driver is selected or defined in hostapd.conf, it appears hostapd defaults to using driver “nl80211”, Driver nl80211 appears to fail using the 8812au for Access Point. For example, using sudo hostapd -dd /etc/hostapd/hostapd.conf, it shows the following:

nl80211: Using driver-based off-channel Tx
nl80211: Interface wlan0 in phy phy0
nl80211: Set mode ifindex 2 iftype 3 (AP)
nl80211: Failed to set interface 2 to mode 3: -19 (No such device)
nl80211: Could not configure driver mode

I'd like to know how to force hostapd to use the driver that supports the Edimax AC600 USB that I obtained as a purchase option when purchasing a PXFMINI from Erle Robotics.

In the Erle Robotics' product purchasing page for the PXFMINI, it promises the external WiFi (802.11ac) wireless modules allows you to connect your robot to a router (which it does do) or create its own WiFi network (hotspot mode) using the 2.4GHz or 5 MHz bandwidth (which it currently fails to do). Thank you for your assistance in helping me to solve this matter.

jackemoore (Jack Moore) 2017-11-09 01:56:42 UTC #4

Hi @LanderU,
I also tried using "driver=rtl8812au" in hostapd.conf and got "invalid/unknown driver 'rtl8812au'".

jackemoore (Jack Moore) 2017-11-14 14:51:05 UTC #5

Hi,
I know your are very busy with more important stuff. Would you share your thoughts on the open questions listed above:

Revisit Question 1
Revisit Question 3a
Revisit Question 3c
Question 3d

Thanks.
Best regards,
Jack Moore

LanderU (Lander Usategui) 2017-11-15 08:32:44 UTC #6

Hi @jackemoore,

sorry!

We need modify the hostapd implementation in order to get the external WiFi working at 5GHz.

It is the correct one, if you're using the dongles provided by Erle Robotics. If you want you can compile yourself another driver, the linux headers for the latest OS are available in our .deb server.

it is caused for the hotspot version.

We builded it to use the internal WiFi, probably we need check the implementation of this version of hostapd to be compliant with other drivers.

Regards,

@LanderU

jackemoore (Jack Moore) 2017-11-15 16:19:42 UTC #7

Hi,

Thanks Lander for your answers to the above questions.

We need modify the hostapd implementation in order to get the external WiFi working at 5GHz.

Question #3e: Is this a priority task and if so, when might it become available?

I'll take a look at what I can do to hostapd on my end.

Thanks.
Best regards,
Jack Moore

jackemoore (Jack Moore) 2017-11-18 01:06:15 UTC #8

Hi,

Follow-up Question:

(a) If hostapd implementation needs to be modified to get the external WiFi working at 5GHz.
(b) If lsmod shows 8812au is loaded and lsusb shows Edimax AC600 is connected.
(c) If the Edimax AC600 dongle was provided by Erle Robotics.
(d) If the driver rtl871zdrv is supposed to support the Edimax AC600.
(e) If the current hostapd version does not recognize driver= rtl1871xdrv in hostapd.conf.
(f) If I've downloaded both the Linux Headers 4.4.50-V7+ and the source code 4.4.y.

Would you share what and/or where the changes need to be made to modify the hostapd implementation to get 5GHz working?

Thanks.

Best regards,
Jack Moore

LanderU (Lander Usategui) 2017-11-18 11:41:22 UTC #9

Hi @jackemoore,

Is not a priority right now. I can put time on it in my free time if is very important for you.

I need to review it deeply to be able to answer you.

Regards,

@LanderU

jackemoore (Jack Moore) 2017-12-05 01:16:03 UTC #10

Hi Lander,

I haven't seen any recent follow-up from erle-robotics concerning 5 GHz AP working in the PXFmini + Rpi0w combo, with the erle-robotics' supplied Edimax AC600 WiFi adapter.

I've been investigating to see if the problem is related to the hostapd service implementation or the installed WiFi USB driver. Since the rtl8812au driver is a kernel driver, I find myself between the proverbial rock and hardplace. Erle-robotics would need to share their custom kernel source and linux-headers packages, and this prevents independent evaluation of alternative drivers for the 8812au version that accompanies the latest OS Image release for PXFmini Debian Jessie (“frambuesa”) [kernel 4.9.21+ #2 PREEMPT 2017 2017 03 13].

Independently, I've evaluated using the Raspbian Jessie [kernel 4.9.35+ #1014 2017 07 05] OS image and used the same driver that is reported to be installed in the latest frambuesa image. The gnab/rtl8812au-4.2.2 driver was compiled and installed in the Raspbian Jessie and I observed the same problem seen in the frambuesa. Following this, I installed a “Fars-Robotics” 8812au.ko build they supply for kernel 4.9.35+ and build #1014. This successfully worked with the Edimax AC600 in both 2.4 GHz and 5 GHz mode.

This experiment suggests that the frambuesa 5 GHz problem is driver related and not necessarily hostapd related. It also suggests that the latest github gnab/rtl8812au version is not compatible with the latest hostapd and the RealTek driver needed for the Edimax AC600.

Github mk-fg/rtl8812au has source code that is reported to contain the latest RealTek driver updates, but it currently doesn't support the ARCH = arm-rpi (armv6l) platform.
The linux kernel driver mk-fg/rtl8812au is a fork of gordboy/rtl8812au (no longer exists), which is based on 5.2.9.3 realtek driver version.

I'm still very much interested in using 5 GHz AP which is separate from the RC 2.4 GHz for the PXFmini.

Best regards,
Jack Moore

jackemoore (Jack Moore) 2017-12-05 18:25:14 UTC #11

Hi Lander,

I have a little more information on my independent evaluation of the linux kernel driver rtl8812au.

As mentioned in the above post, using Raspbian Jessie [kernel 4.9.35+ #1014 2017 07 05] OS image (I can also easily get the kernel source code and linux-headers), installing the fars-robotics 8812au.ko build worked successfully with the Edimax AC600 in 5 GHz AP mode. This was made possible because the kernel and headers were not customized as is the case of erle-robotics.

In addition, installing the gnab/rtl8812au v 4.2.2 from source was successful, but failed to work with the Edimax AC600.

I've also tried installing diederikdehaas/rtl8812au v 4.3.14 from source, the install was successful and this worked successfully with the Edimax AC600.

I propose erle-robotics generate a new release of the image for PXFmini Debian Jessie (“frambuesa”), using the kernel driver from diederikdehaas/rtl8812au in place of gnab/rtl8812au that has not worked with the Edimax AC600.

Alternatively, I'm willing to try this myself, if erle-robotics can temporarily loan the kernel and headers for PXFmini frambuesa.

Best regards,
Jack

jackemoore (Jack Moore) 2017-12-13 13:22:48 UTC #12

H Lander,

I'm still waiting for a reply from you.

Best regards,
Jack

patmaherjfm (pat) 2018-04-17 23:33:38 UTC #13

any news, this is way over my head, not fit for purpose comes to mind. correct me if im wrong, 5g hotspot does not work, will it ever work, did i buy a useless adaptor

LanderU (Lander Usategui) 2018-04-23 08:31:59 UTC #14

Hi @patmaherjfm,

check out this thread please: http://forum.erlerobotics.com/t/rtl8812au-wifi-update/3875

Regards,

@LanderU

patmaherjfm (pat) 2018-04-25 23:21:57 UTC #15

The module only can run under 4.4.50-v7+ SMP PREEMPT kernel version
dpkg: error processing archive /var/cache/apt/archives/rtl8812au-driver-erle-brain_0.1_armhf.deb (--unpack):
subprocess new pre-installation script returned error exit status 1

Can i get a erlebrain3 image ? i bought only the pfxmini
I have the pi3, and it's mostly working, every time I mess with this 5g thing I end up starting from scratch. .
erle@erle-brain-2 ~ $ uname -r
4.4.20-v7+