Issue with Gert Enable_UART for Gertbot on Pi 2 .

[whoatealldapis]

Hi
I am trying to get the Gertbot GUI running on a Raspberry Pi 2 and first I need to enable the UART. Unfortunately I get the following:

Code: Select all

$ sudo ./enable_uart cfr
Error checking /boot/cmdline.txt
Looks like /etc/inittab needs fixing

I don't think that there is an inittab file on a Raspberry Pi 2 so how can I get around this ?... Does this mean that the Gertbot will not work on a Raspberry Pi 2 ?

thanks in advance ....

[whoatealldapis]

Further to this... I think that this is related to there being no inittab in the latest version of Raspbian (versus Pi 2). So... Is there a revision to the GertBot software for it to work on the Jessie Build of Raspbian.

[whoatealldapis]

for completeness.. a downgrade to Raspbian Wheezy fixed the issues. Seems there is an incompatibility between Gert's set up software and Jessie for now.

[dbenhart]

Does anyone know if there has been progress on the software revision? I'm having trouble locating a download for Raspbian Jessie, and for security reasons I'd rather just use the most recent OS anyway.

[ab-robotics]

Yup, the Gertbot seems meanwhile unusable with the Raspberry Pi. The software provided on the Gertbot website was written for the outdated Rasbian Wheezy, which is even not on the Raspberry download pages anymore.

The core problem is that the Gertbot software to enable the UART is neither working with the current Raspbian Jessie nor with Ubuntu 14.04 for Raspberry. I guess the move to systemd made the modification of inittab in the Gertbot software obsolete and that now a bunch of new hacks are needed to get the UART communication going with the Gertbot. I wasted already two days without success on this - the fact that the commands are binary makes debugging not really easier. After all, I spend the money for that board to NOT have to do low-level UART debugging to get anything going.

If anybody has managed to set-up the UART under Raspbian Jessie or Pi-Ubuntu, please post a reply. I am not sure whether Gert reads these posts - or whether somebody knows how to contact him. But a fix posted on the Gertbot website would be great and likely help a lot of people who may still buy these boards. The Gertbots are sold at RS-components, Farnell, etc., i.e., very "professional" electronics suppliers, explicitly advertising the use with the Raspberry Pi. I hence expected that at least the basic set-up on the Pi is working.

[st0rmforce]

I got around the problem by doing it manually.
All the enable uart app does, is removes references to the ttyAMA0 uart from /boot/cmdline.txt and inittab. Seeing as inittab doesn't exist I just manually went in and stripped it out of cmdline.txt. I just made a backup and then removed "console=ttyAMA0,1105200" from the first line Worked like a charm for me.

Another way you could possibly do this (although I haven't tried), is to create a dummy /etc/inittab with some dummy content (just to keep gert's app happy), then run the enable uart, then delete the dummy file.

It's just the way the enable app is written, that it won't do anything if it doesn't see what it expects.

[st0rmforce]

By the way, I also had trouble with the C and python drivers. Not sure if it's related to the OS update.

Basically, the GUI binary worked fine once I'd enabled the uart, I could control 4 motors perfectly. Downloaded the driver, opened up python, made a little test: nothing. Realised I was using python 2.7, changed to 3.4, tried again... nothing. I tried the examples on the gertbot site and nothing worked. I also tried the C driver and the included test app... still nothing.

I then started fiddling with python again. I knew it was just sending a few bytes to a tty device, really nothing complicated. I opened the tty device, I copied a command from the GUI log, stuck the head and tail bytes on, wrote it to the file descriptor. Success!
I'll do some more experiments tonight and see if I can work out exactly what the problem is, but bottom line is that it does work. I have a rudimentary homespun python driver that I can use now.

The annoying thing, is that it's a great piece of hardware and very easy to use, but none of the software on the website works out of the box on a up-to-date Pi 2 B. Although it doesn't actually take much to get it working, you need to be confident enough to fiddle about. A beginner would not be able to use it in its current state.

[craigjohnstone]

By the way, I also had trouble with the C and python drivers. Not sure if it's related to the OS update.

Basically, the GUI binary worked fine once I'd enabled the uart, I could control 4 motors perfectly. Downloaded the driver, opened up python, made a little test: nothing. Realised I was using python 2.7, changed to 3.4, tried again... nothing. I tried the examples on the gertbot site and nothing worked. I also tried the C driver and the included test app... still nothing.

I then started fiddling with python again. I knew it was just sending a few bytes to a tty device, really nothing complicated. I opened the tty device, I copied a command from the GUI log, stuck the head and tail bytes on, wrote it to the file descriptor. Success!
I'll do some more experiments tonight and see if I can work out exactly what the problem is, but bottom line is that it does work. I have a rudimentary homespun python driver that I can use now.

The annoying thing, is that it's a great piece of hardware and very easy to use, but none of the software on the website works out of the box on a up-to-date Pi 2 B. Although it doesn't actually take much to get it working, you need to be confident enough to fiddle about. A beginner would not be able to use it in its current state.

This makes sense now! I am having problems with the Gertbot. I can get the GUI working but it doesn't recognise the board. I'm on a Pi3. Really annoying, hope it gets a fix...

[craigjohnstone]

I got around the problem by doing it manually.
All the enable uart app does, is removes references to the ttyAMA0 uart from /boot/cmdline.txt and inittab. Seeing as inittab doesn't exist I just manually went in and stripped it out of cmdline.txt. I just made a backup and then removed "console=ttyAMA0,1105200" from the first line Worked like a charm for me.

Another way you could possibly do this (although I haven't tried), is to create a dummy /etc/inittab with some dummy content (just to keep gert's app happy), then run the enable uart, then delete the dummy file.

It's just the way the enable app is written, that it won't do anything if it doesn't see what it expects.

Hi, I'm trying the same but my /boot/cmdline.txt reads:
dwc_otg. lmp_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p7 roofstype=ext14 elevator=deadlink fsck repair=yes rootwait

Any ideas what I need to delete from this?
Craig

[Chrisv7167]

I am using pi 3 with gertbot and having them same issues with finding they connected gertbot board. Does anyone have any updates on this issue?