failed to set dtr/rts

[tobru]

Just tried the master branch of the Pymakr plugin, but no change in behaviour.

[jmarcelino]

@tobru
Can you try
stty -crtscts < /dev/ACM3

from the Linux shell to disable hardware flow control?

[tobru]

@jmarcelino Thanks for your input. I've tried this, but this command leads to the same error message: cdc_acm 3-1.2:1.0: failed to set dtr/rts. And connections from Atom don't work neither.

[g0hww]

New user here, and I've just experienced the same thing.

I got my first lopy yesterday along with an Expansion Board 2.0 and had no issues getting them up and running (including yesterdays fresh FW update). Had the lopy connecting to my WLAN and the FTP/telnet server accessible. Also had no probs with the USB UART connectivity via the ExpBrd2 with the dev tools in the Atom editor and with GNU-screen.

Today my first pytrack board arrived. I DFU updated it with the latests FW and then I fetched the libs from github and was about to sync the 3 libs onto the device, when the Sync in Atom failed. The device no longer responded on the serial port. I looked at the dmesg output, and it is the issue described above.

I've un/replugged the device a few times. The handshaking error occurs in dmesg output whenever a prog tries to access /dev/ttyACMx. I also have an Arduino, which seems to use the same USB UART driver and that's working fine still (note that for the avoidance of doubt, it was not plugged in when the issue arose, I only plugged it on to verify that it still worked).

I'm running Ubuntu 16.04 LTS x86_64 on kernel 4.10.0-30.

I can still access the device over telnet and ftp. I assume that I would regain serial connectivity with the lopy if if reverted to the ExpBrd2, but I really want to play with the lopy and pytrack.

I notice there has been no updates on this topic for a while. Is this a known problem, or have workarounds been discovered?

[g0hww]

I got someone else with a Windows PC to try it, and it seemed to be working for him. I laughed when he used Labview to decide whether or not it was working :)

After I googled around a bit, I stumbled across hints that rebooting the host might resolve it, so I did and it is now connecting again via the USB UART on the pytrack board. I've just been able to sync the 3 libs across and still have the REPL up. Will post back if there are other developments.

[g0hww]

This is still giving me grief. My first lopy is on a pytrack board, and I now find that I can never sync it without first running os.mkfs('/flash'), otherwise i get these errors:

"Synchronizing failed: Write failed. Please reboot your device manually."

That means that i then have to sync again using the USB UART. As the CDC ACM device on the PyTrack doesn't work properly with my Linux kernel (see above), I have to temporarily borrow the ExpBrd2 from my other lopy in order to sync with it using the FTDI USB UART. This makes it hard to debug code specifcally written for the pytrack!

It also sounds like my first lopy's /flash is worn out after a couple of weeks! Is this possible? What else might cause this sudden inability to reprogram it over telnet?

[on4aa]

I am having exactly the same issue on Ubuntu 16.04 LTS with Linux kernel 4.4.0-104-generic.

[ 4839.468011] usb 1-7.2: new full-speed USB device number 13 using ehci-pci
[ 4839.562840] usb 1-7.2: New USB device found, idVendor=04d8, idProduct=f013
[ 4839.562842] usb 1-7.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 4839.562844] usb 1-7.2: Product: Pytrack
[ 4839.562846] usb 1-7.2: Manufacturer: Pycom
[ 4839.562847] usb 1-7.2: SerialNumber: Py343434
[ 4839.564381] cdc_acm 1-7.2:1.0: ttyACM0: USB ACM device
[ 4839.604727] cdc_acm 1-7.2:1.0: failed to set dtr/rts
[ 4841.039182] TCP: request_sock_TCP: Possible SYN flooding on port 46233. Sending cookies.  Check SNMP counters.

The TCP SYN flooding seems to coincide with the failed to set dtr/rts. The port number changes with every attempt. I hope it is no Chinese malware that sneaked its way into my new LoPy PyTrack & LoPy PySense devices!

A Pycom bug report has been opened for this issue.

[on4aa]

I also tried disabling the Modem Manager service as this has been seen to interfere with other development boards. It did not cure the problem, though.

$ sudo systemctl disable ModemManager.service

[on4aa]

I made some progress. ModemManager is part of the problem as Pycom devices are not blacklisted in the following file:

$ less /lib/udev/rules.d/77-mm-usb-device-blacklist.rules

Editing this file is of no use since it will be overwritten with any update.
One may file a bug report against ModemManager to have Pycom devices added to this system file.

User device rules reside in /etc/udev/rules.d/. These device rule files take precedence over those located in /lib/udev/rules.d/ if their name is identical.

Hence, a file under a different name was created, namely 77-mm-pycom.rules:

$ sudo vim /etc/udev/rules.d/77-mm-pycom.rules

which contains the following rule:

# All devices from Pycom LTD
ATTRS{idVendor}=="04d8", ENV{ID_MM_DEVICE_IGNORE}="1"

If only the most recent Pysense devices are to be blacklisted, use:

# Pycom Pysense
ATTRS{idVendor}=="04d8", ATTRS{idProduct}=="f012", ENV{ID_MM_DEVICE_IGNORE}="1"

Similarly for the most recent Pytrack devices:

# Pycom Pytrack
ATTRS{idVendor}=="04d8", ATTRS{idProduct}=="f013", ENV{ID_MM_DEVICE_IGNORE}="1"

I do not own any other or earlier version expansion boards. These will undoubtedly carry another idProduct. Since Pycom is not producing any modems, it is safe to blacklist all Pycom LTD devices.

RESULT
Upon device connection, there is no longer a failed to set dtr/rts error in the dmesg listing.
However, it reappears there when attempting a ./update, which still fails.
The TCP: request_sock_TCP: Possible SYN flooding on port nnnnn. Sending cookies. Check SNMP counters. still appears in dmesg at device connection.

CONCLUSION
ModemManager was part of the problem. There is still another unresolved issue.

PS: I find it hard to believe there are so few people developing on Pycom with Ubuntu.

[on4aa]

In the ./update script, the error occurs at get_wmac.

Manually running ./updater.py results in:

$ ./updater.py --port "/dev/ttyACM0" --speed 115200 wmac
Connecting...
Exception: [Errno 32] Broken pipe, on line 161

[on4aa]

The same issue seems to affect any attempt to upgrade the firmware of the Pysense or Pytrack itself (instead of the plugged in LoPy): dfu-util: Cannot open DFU device 04d8:f014

dfu-util -D pytrack_0.0.8.dfu 
dfu-util 0.8

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2014 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to dfu-util@lists.gnumonks.org

Match vendor ID from file: 04d8
Match product ID from file: f014
dfu-util: Cannot open DFU device 04d8:f014
dfu-util: No DFU capable USB device available

[on4aa]

(LoPy) module updates via the Pysense or Pytrack board is neither currently possible with other GNU/Linux distributions; for example Manjaro XFCE, which I tried.

From what I am reading, GNU/Linux users can only install module firmware upgrades using the ordinary Expansion board, which I currently do not own.

[livius]

@on4aa

can only install module firmware upgrades using the ordinary Expansion board,

And also by any 3V3 UART/TTL converter

[Xykon]

It should also be possible to upgrade the esp32 firmware using the Pytrack / Pysense by disabling high speed transfer and connecting a jumper wire between Pin 1 and Pin 5 on the external IO header.

We're planning to release a new firmware update tool today (or very shortly) that will support updating via Pysense / Pytrack using high speed transfer and without needing a jumper wire.

This should work on all operating systems when using the GUI version of the firmware update tool. This will not initially work with the dialog based cli updater that is included in the Linux version of the firmware update tool, but I will post some workaround instructions when the software is released.

[on4aa]

@xykon

I could update the firmware of the Pysense & Pytrack boards, but still no luck with the ESP32 firmware.

$ sudo dfu-util -D pysense_0.0.8.dfu
$ sudo dfu-util -D pytrack_0.0.8.dfu

The sudo should be added to the documentation.

[on4aa]

@xykon
At last, success! The ESP32 firmware update (GUI-version) succeeded now, after creating /etc/udev/rules.d/77-mm-pycom.rules containing:

# All devices from Pycom LTD
# Since Pycom is not producing any modems, it is safe to blacklist all Pycom LTD devices.
ATTRS{idVendor}=="04d8", ENV{ID_MM_DEVICE_IGNORE}="1"

and rebooting! (I probably forgot to do so late last night.)

I am not sure whether first upgrading the firmware of the Pysense or Pytrack board with sudo dfu-util is a necessary preceding step, but that is what I did first.

Anyhow, I filed a ModemManager bug report so that fellow Pycom developers on GNU/Linux will no longer be bothered with this issue in the future.

[jmarcelino]

@on4aa
Hi,

Thanks a lot for your investigation but I have to say 0x04d8 is Microchip's vendor ID (Pycom uses a Microchip PIC micro for the USB-serial interface and we sublicense their VID) so it's probably unwise to add it as a general rule for all ModemManager installs.

[Xykon]

@on4aa said in failed to set dtr/rts:

I could update the firmware of the Pysense & Pytrack boards, but still no luck with the ESP32 firmware.

$ sudo dfu-util -D pysense_0.0.8.dfu
$ sudo dfu-util -D pytrack_0.0.8.dfu

The sudo should be added to the documentation.

A better solution is to use sudo usermod -a -G dialout $USER once and then logout or reboot your PC. Then you can use dfu-util without sudo.

I will make sure this gets added to the documentation.

[on4aa]

@jmarcelino
Well, then a list of all of Pycom's current (and planned?) idProduct values is needed. See examples below.
Any future additions will have to be reported to freedesktop.org ModemManager maintainers.

[on4aa]

@xykon Oddly enough, I have been a member of the dialout group long before this. This is why it also surprised me.

Either the python script is not getting full privileges or I was not trained at the beginning with pressing the buttons. This needs more testing.

PS: A reputation point or so is more than welcome. As a newbee I have nada ;-)