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by rin67630
Sat Feb 16, 2019 9:30 pm
Forum: Troubleshooting
Topic: Do we have a way to invert the logic of the GPIO serial port?
Replies: 16
Views: 365

Re: Do we have a way to invert the logic of the GPIO serial port?

If you can bear with me for a couple of days I should have something suitable to post here. I am very grateful for your help, we have got time, albeit I am very excited to get your improvements. It is surely a huge progress to get this flexibility, not only for my requirements but surely for many o...
by rin67630
Sat Feb 16, 2019 8:27 am
Forum: Troubleshooting
Topic: Do we have a way to invert the logic of the GPIO serial port?
Replies: 16
Views: 365

Re: Do we have a way to invert the logic of the GPIO serial port?

That should be achievable with a software UART. There is this from Adriano Marto Reis which provides an installable module and, once installed, data is read from and sent to /dev/ttySOFT0 just like any other serial interface - https://github.com/adrianomarto/soft_uart I have taken that and inverted...
by rin67630
Sat Feb 16, 2019 8:20 am
Forum: Troubleshooting
Topic: Do we have a way to invert the logic of the GPIO serial port?
Replies: 16
Views: 365

Re: Do we have a way to invert the logic of the GPIO serial port?

Usb to serial ttl adapters based on FTDI FT232 chip can set polarity selectively on each pin. There is a tool ft_prog (also for linux ) that can set it. Most such cheap adapters e.g. on ebay are clones but setting tne polarity should work. i have one such cheap adapter and use it with changed polar...
by rin67630
Wed Feb 13, 2019 8:08 am
Forum: Troubleshooting
Topic: Do we have a way to invert the logic of the GPIO serial port?
Replies: 16
Views: 365

Re: Do we have a way to invert the logic of the GPIO serial port?

The device I am using sends one byte every second at 9600 baud, it has got a setup procedure as well that reads a byte and answers with a byte. Eveything is pretty slow and simple. I bypassed the "poorman" passive RS232 circuitry (consisting of just resitors and clamping diodes) and i have included ...
by rin67630
Mon Feb 11, 2019 11:43 pm
Forum: Troubleshooting
Topic: Do we have a way to invert the logic of the GPIO serial port?
Replies: 16
Views: 365

Re: Do we have a way to invert the logic of the GPIO serial port?

Hi, I am trying to interface a serial device to the GPIO. As I have seen the Serial GPIo works with negative logic: the signal is normally high and the serial bits are lows. My device outputs the signal in positive logic. I would like to avoid having to wire a hardware inverter. Do we have a way to...
by rin67630
Mon Feb 11, 2019 9:52 pm
Forum: Troubleshooting
Topic: Do we have a way to invert the logic of the GPIO serial port?
Replies: 16
Views: 365

Do we have a way to invert the logic of the GPIO serial port?

Hi, I am trying to interface a serial device to the GPIO. As I have seen the Serial GPIo works with negative logic: the signal is normally high and the serial bits are lows. My device outputs the signal in positive logic. I would like to avoid having to wire a hardware inverter. Do we have a way to ...
by rin67630
Mon Feb 11, 2019 11:05 am
Forum: Raspbian
Topic: Easiest way to send a looped string to /dev/ttyAMA0?
Replies: 3
Views: 76

Re: Easiest way to send a looped string to /dev/ttyAMA0?

Thank you for the help. Excuse me, I am a noob. I am working on a Raspi 3A+ I have the follwing in /boot/config.txt to enable AMA0 to GPIO: # Swap Serial ports and Bluetooth dtoverlay=pi3-miniuart-bt enable_uart=1 The baud rate is set with stty. The serial input works on Minicom but not the output. ...
by rin67630
Mon Feb 11, 2019 10:27 am
Forum: Raspbian
Topic: Easiest way to send a looped string to /dev/ttyAMA0?
Replies: 3
Views: 76

Easiest way to send a looped string to /dev/ttyAMA0?

I am looking for an easy way to send an arbitrary string looped infinitely to /dev/ttyAMA0 for debugging purposes.
Ideally a bash script.
Has someone a clue how to manage that?
Thank you in advance.
Regards
Laszlo
by rin67630
Wed Jan 23, 2019 8:48 pm
Forum: Raspberry Pi Desktop for PC and Mac
Topic: To simon: could the next version include arandr as well?
Replies: 6
Views: 890

Re: To simon: could the next version include arandr as well?

IMHO all the requests like "you should include (insert your favorite software here)" are just tiresome. The RPi DE is, by necessity, very lightweight. Adding things that are not nearly universally needed would cause it to be other than lightweight, thereby defeating the Foundation's purpose in rele...
by rin67630
Thu Jan 10, 2019 10:07 am
Forum: Troubleshooting
Topic: Pi B+ Headless SSH Stopped Working
Replies: 7
Views: 231

Re: Pi B+ Headless SSH Stopped Working

Actually you can end up with connection refused if the IP has changed , if you have several devices on your wifi network and the router is reset or all the IP's are reset by the router you could find you are not connected to the pi but one of the other devices hence no ssh and connection refused. T...
by rin67630
Tue Jan 08, 2019 10:03 pm
Forum: Troubleshooting
Topic: Pi B+ Headless SSH Stopped Working
Replies: 7
Views: 231

Re: Pi B+ Headless SSH Stopped Working

This worked great for about a day, until the SSH randomly started replying "Connection Refused". "Connection refused" occurs when you have got an IP connection (a ping should work), but no SSH or VNC service. Can you try to connect a mouse to your headless Pi? Just connect a mouse and reboot. Does ...
by rin67630
Tue Jan 08, 2019 9:54 pm
Forum: Troubleshooting
Topic: VNC viewing or RPi prompt from Windows
Replies: 7
Views: 252

Re: VNC viewing or RPi prompt from Windows

pinion wrote:
Sun Jan 06, 2019 10:18 pm
Is VNC only for desktop sessions?
Yes VNC is video from the desktop.
But you can run the terminal from there...
by rin67630
Tue Jan 08, 2019 8:49 pm
Forum: Troubleshooting
Topic: Pi3 A+ VNCSERVER startup too long
Replies: 10
Views: 310

Re: Pi3 A+ VNCSERVER startup too long

Try to plug a mouse in the headless RPi.
If it starts without delay, the solution is here:
viewtopic.php?f=28&t=230779&p=1413648#p1413648
The SOLUTION: install haveged (an entropy generator that does not need a mouse)
sudo apt-get install haveged.
by rin67630
Tue Jan 08, 2019 8:44 pm
Forum: Troubleshooting
Topic: Vnc Connect to a headless Pi
Replies: 20
Views: 14111

Re: VNC does not connect to a headless Pi

The service fails to start or starts erratically delayed by several minutes. What I found out: the service starts immediately when a mouse is connected at boot time! When no mouse is connected at boot time, the service does not start, and starts a few seconds after the mouse was connected to USB! T...
by rin67630
Tue Jan 08, 2019 4:57 pm
Forum: Troubleshooting
Topic: Headless Raspberry Pi Model 3 A+: cannot ssh over wifi on first boot
Replies: 6
Views: 258

Re: Headless Raspberry Pi Model 3 A+: cannot ssh over wifi on first boot

Just make a simple test: plug a mouse into your headless Pi. Does it work? If yes: It seems that "crng init done" is, without a mouse, blocking your boot porcess. At boot, the kernel waits for mouse movements to initialize the random number generator. The SOLUTION: install haveged (an entropy genera...
by rin67630
Tue Jan 08, 2019 4:32 pm
Forum: Troubleshooting
Topic: SOLUTION: VNC does not start on a headless Raspberry pi.
Replies: 2
Views: 350

SOLUTION: VNC does not start on a headless Raspberry pi.

I have massive problems to start a headless Raspberry Pi 3a (or a Zero W) running 2018-11-13-raspbian-stretch with VNC enabled. The strnage thing is that being completely headless (without any Mouse/Keyboard) the system boots onto the desktop, stays many minutes (frequently forever) without loading ...
by rin67630
Tue Jan 08, 2019 4:13 pm
Forum: Linux Kernel
Topic: Boot hang after "random: crng init done"
Replies: 10
Views: 20805

Re: Boot hang after "random: crng init done"

At boot, the kernel waits for mouse movements to initialize the random number generator. /quote] Ugh! that seem a valid explanation: I am running headless and HAVE NO MOUSE NOR KEYBOARD. Pluging a mouse releases the boot process. But that is'nt the purpose of a headless machine! Installing haveged ...
by rin67630
Fri Jan 04, 2019 9:03 pm
Forum: Troubleshooting
Topic: Vnc Connect to a headless Pi
Replies: 20
Views: 14111

Re: VNC does not connect to a headless Pi

[...] A virtual mode server may be what you want, but I'm really interested to know why the service mode server failed to start for you . Did you try running the "sudo systemctl status vncserver-x11-serviced" command to see if it is actually running or has stopped for some reason? I have got exactl...
by rin67630
Fri Jan 04, 2019 3:44 am
Forum: Troubleshooting
Topic: Vnc Connect to a headless Pi
Replies: 20
Views: 14111

Re: VNC does not connect to a headless Pi

JFYI You really shouldn't have to do that if your enabled VNC using raspi-config [...] A virtual mode server may be what you want, but I'm really interested to know why the service mode server failed to start for you . Did you try running the "sudo systemctl status vncserver-x11-serviced" command t...
by rin67630
Thu Jan 03, 2019 8:16 pm
Forum: Raspberry Pi Desktop for PC and Mac
Topic: Dual boot laptop running Debian x86 with the RPI desktop?
Replies: 18
Views: 690

Re: Dual boot laptop running Raspbian?

Thanks for the option. Prefer install on same hardware as will use on the go and on hols etc from time to time I think. Both options don't follow the same purpose. It makes sense to code for Raspbian runnning ARM, which has got GPIO. Debian with the look an feel of Raspbian is fun, but is not the v...
by rin67630
Thu Jan 03, 2019 8:55 am
Forum: Raspberry Pi Desktop for PC and Mac
Topic: Dual boot laptop running Debian x86 with the RPI desktop?
Replies: 18
Views: 690

Re: Dual boot laptop running Raspbian?

Another option is to remote connect to a RPi from the Win10 machine using ssh (text terminal only) or VNC (Full GUI). (The laptop and RPi would need to be connected to the local network by wire or WIFI) Thanks for the option. Prefer install on same hardware as will use on the go and on hols etc fro...
by rin67630
Thu Dec 27, 2018 7:59 pm
Forum: Raspbian
Topic: matchbox keyboard
Replies: 22
Views: 6561

Re: matchbox keyboard

I have installed Matchbox keyboard, i want display the keyboard in front end of tkinter gui but its matchbox keyboard is opening in the backend of my gui application. Please anyone help me in this. Seem to be a bug/wrong programming of TKinter... Can you put another application window in the foregr...
by rin67630
Wed Dec 26, 2018 2:50 pm
Forum: Troubleshooting
Topic: Accidently used 12v power supply on Raspberry Pi 3 B + help
Replies: 24
Views: 980

Re: Accidently used 12v power supply on Raspberry Pi 3 B + help

i will take a better look at the schematic for the 3B+ which i have a link to earlier in this forum post, it has full model numbers of all parts, i think, plus the full schematics, again, i think they are complete, not just for quick-reference. I'm not sure though.. Recent published schematics are ...
by rin67630
Wed Dec 26, 2018 1:27 pm
Forum: Raspbian
Topic: matchbox keyboard
Replies: 22
Views: 6561

Re: matchbox keyboard

How to display a matchbox keyboard in front end of a GUI, when the cursor is clicked the text field. Please help me with this scenario. Once you have installed matchbox-keyboard with: sudo apt-get install matchbox-keyboard and rebooted, you should have got the progamm keyboard listed in the menu ac...
by rin67630
Wed Dec 26, 2018 11:44 am
Forum: Raspbian
Topic: matchbox keyboard
Replies: 22
Views: 6561

Re: matchbox keyboard

I have a Pi 3 B+ with stretch I have tried to install matchbox-keyboard with sudo apt-get install matchbox-keyboard and I got: E: Unable to locate package matchbox-keyboard what am I missing ? a good internet connection? sudo apt-get install matchbox-keyboard worked like a charm here from stock Ras...

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