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by pleriche
Mon Dec 10, 2018 10:50 pm
Forum: Advanced users
Topic: Co-existing devices on i2c bus
Replies: 5
Views: 1731

Re: Co-existing devices on i2c bus

For the sake of anyone stumbling across this thread in the future, the problem was a very stupid bug (aren't they all?) in my PIC assembly code, the sort you can stare at for hours and not see. (Well, that's my excuse, anyway.)
by pleriche
Sun Dec 09, 2018 10:15 am
Forum: Advanced users
Topic: real/fake hwclock/ntp interaction
Replies: 1
Views: 216

real/fake hwclock/ntp interaction

From what I've read it seems you have to uninstall fake-hwclock if you've got a real one (e.g. DS1307). But I want my Pi to do the best it can given that it may or may not have the DS1307 plugged in today which may or may not have been initialised, and it may or may not have a network connection. In...
by pleriche
Fri Nov 23, 2018 10:42 am
Forum: Advanced users
Topic: Co-existing devices on i2c bus
Replies: 5
Views: 1731

Re: Co-existing devices on i2c bus

A software problem. My Systems Architect (me) didn't appreciate the complexity of his proposed solution and failed to properly specify the implementation. My Project Manager (me) was hassling my Principal Programmer over missed milestones. My Principal Programmer (me) frankly wasn't up to the job an...
by pleriche
Tue Nov 20, 2018 8:50 pm
Forum: Advanced users
Topic: Co-existing devices on i2c bus
Replies: 5
Views: 1731

Re: Co-existing devices on i2c bus

Thank you 6by9 - I'll bear that in mind when I get around to upgrading to Stretch. As always, when you've proved the fault can't exist and yet it's mocking you to your face, the thing to do is to go back to the start and recheck everything. I went back to my Mk I version running under an ancient Whe...
by pleriche
Mon Nov 19, 2018 12:27 pm
Forum: Advanced users
Topic: Co-existing devices on i2c bus
Replies: 5
Views: 1731

Co-existing devices on i2c bus

About 5 years ago I built a Pi midi interface around a PIC microcontroller, using I2C to communicate with a user-space Python program on the Pi, running Wheezy. This was working fine until a month or two ago. Last Summer I built a Mk II version using a PIC with more pins to allow me to include funct...
by pleriche
Sun May 27, 2018 10:02 pm
Forum: Troubleshooting
Topic: i2c problem on PiZero v1.2
Replies: 1
Views: 141

Re: i2c problem on PiZero v1.2

I've now tried various combinations of old/new interface on different Pis and different OS's and the results are as follows: Original Pi Model B: Wheezy: Both old and new interfaces work PiZeroV1.2: - Stretch: - - Old interface worked maybe a couple of years ago - - New interface now doesn't work - ...
by pleriche
Fri May 25, 2018 9:30 pm
Forum: Troubleshooting
Topic: i2c problem on PiZero v1.2
Replies: 1
Views: 141

i2c problem on PiZero v1.2

Some 5 years ago I built an intelligent midi interface using a PIC16F1823 8 bit microcontroller, which interfaces with the Pi using i2c. (The PIC is working as an i2c slave.) I use this fairly regularly with one of my original Pi Model B's, still running Wheezy. At one stage I tried replacing the Pi...
by pleriche
Sat May 05, 2018 9:31 pm
Forum: Beginners
Topic: install flashrom on rp 0
Replies: 3
Views: 1215

Re: install flashrom on rp 0

In case anyone is watching this or stumbles across it, I downloaded the source and successfully built it to drive SPI devices through /dev/spi* with: make CONFIG_ENABLE_LIBPCI_PROGRAMMERS=no CONFIG_ENABLE_LIBUSB0_PROGRAMMERS=no CONFIG_ENABLE_LIBUSB1_PROGRAMMERS=no It appeared to work, typing ./flash...
by pleriche
Wed Apr 04, 2018 10:55 am
Forum: Troubleshooting
Topic: Raspbian Stetch Lite - VNC gives tiny window
Replies: 3
Views: 328

Re: Raspbian Stetch Lite - VNC gives tiny window

To confirm, works fine with Stretch Hevi. Initially vnc gave me a window which seemed to be 660x420 (no idea where it got that resolution from), and changing it in raspi-config from the default of 720x480 to 1024x768 worked. Will probably stick with Hevi. I went for light thinking that was an old 4G...
by pleriche
Wed Apr 04, 2018 10:25 am
Forum: Troubleshooting
Topic: Raspbian Stetch Lite - VNC gives tiny window
Replies: 3
Views: 328

Re: Raspbian Stetch Lite - VNC gives tiny window

Hmmm... that didn't work either. Just reflashing my SDCard with Raspbian Stretch Hevi (non-Lite) which I imagine has vnc pre-installed.
by pleriche
Wed Apr 04, 2018 9:30 am
Forum: Troubleshooting
Topic: Raspbian Stetch Lite - VNC gives tiny window
Replies: 3
Views: 328

Raspbian Stetch Lite - VNC gives tiny window

I downloaded the latest Raspian Stretch Lite 2018-03-13 for my PiZero 1.2 (no camera connector or WiFi), used a console connection to enable ssh, then in raspi-config, I enabled boot into GUI and VNC. Connecting with VNC I got a mini 200x300 pixel window only. I've had that before, and knew that all...
by pleriche
Sat Aug 12, 2017 4:52 pm
Forum: General discussion
Topic: Adafruit MPL115A2 Temp/Pressure sensor - Python
Replies: 6
Views: 3595

Re: Adafruit MPL115A2 Temp/Pressure sensor - Python

Glad it's still useful, nearly 3 years later!

Regards - Philip
by pleriche
Thu Jun 22, 2017 2:34 pm
Forum: Advanced users
Topic: VNC sessions hang
Replies: 0
Views: 219

VNC sessions hang

For several weeks I've been chasing an intractable problem with VNC sessions hanging. They generally recover after around 30 seconds. I wonder if it rings any bells with anyone round here? We have a bunch of headless classroom Pis on their own NATted subnet, which is connected to the school network ...
by pleriche
Tue May 16, 2017 3:07 pm
Forum: Troubleshooting
Topic: autocutsel on Jessie
Replies: 1
Views: 346

Re: autocutsel on Jessie

OK, let's put this another way. A ps listing shows autocutsel is already running as a daemon (parent pid is 1) though I've grepped all the way through /etc and can't see what initiates it, but no matter. Running VNC under Windows, I can cut and paste from a window in the VNC session to Notepad in Wi...
by pleriche
Mon May 15, 2017 4:16 pm
Forum: Troubleshooting
Topic: autocutsel on Jessie
Replies: 1
Views: 346

autocutsel on Jessie

My standard practice on Wheezy was to enable cut'n'paste between a VNC session and the host by installing autocutsel then adding autocutsel -fork to .vnc/xstartup immediately before the /etc/X11/Xsession command. But on Jessie, .vnc only contains an empty directory config.d and I don't see a file an...
by pleriche
Sat Feb 18, 2017 6:30 pm
Forum: Raspbian
Topic: VNC server in Jessie (using a systemd service)
Replies: 25
Views: 93851

Re: VNC server in Jessie (using a systemd service)

Having come back to this a good few months later I find that the answer is very simple: in .vnc/xsession insert: cd $HOME anywhere before the last line. I don't know why this is necessary on Jessie but not on Wheezy. This works fine for me - thanks xanthor. Just one little niggle: when I start LXter...
by pleriche
Thu Oct 13, 2016 7:52 pm
Forum: Advanced users
Topic: Connecting using IPv6 Link Local
Replies: 4
Views: 1583

Re: Connecting using IPv6 Link Local

Thanks for the replies. I only needed to do this in order to solve another urgent problem, which I've now sidestepped in a different way, so I'll come back to it later when I have more time and try and work out properly what was going on. In fact on 2 occasions I managed to ping in one direction but...
by pleriche
Wed Oct 12, 2016 11:15 am
Forum: Advanced users
Topic: Connecting using IPv6 Link Local
Replies: 4
Views: 1583

Connecting using IPv6 Link Local

I need to temporarily connect my (Win7) laptop to a (headless) Pi (Wheezy) with PuTTY at a location where the WiFi is flaky, using a direct network cable. (Laptop NIC is auto-sensing, so no crossover needed.) My first though was to allow the laptop and Pi to auto-configure with 169.254 addresses, an...
by pleriche
Wed Jul 20, 2016 4:26 pm
Forum: Python
Topic: os.system() in cgi script
Replies: 5
Views: 1253

Re: os.system() in cgi script

Thank you - I think you have the answer. Neither os.system in the Python library reference nor the system(3) man page say what happens to stdout from the command, leaving the naive user to assume the command inherits stdout from the parent process. Evidently not, though I'm still trying to get my he...
by pleriche
Wed Jul 20, 2016 10:51 am
Forum: Python
Topic: os.system() in cgi script
Replies: 5
Views: 1253

Re: os.system() in cgi script

RaTTuS wrote:full path to date ?
Good try - I'm sure that's caught me out before, but os.system("/bin/date") is the same.
by pleriche
Wed Jul 20, 2016 10:32 am
Forum: Python
Topic: os.system() in cgi script
Replies: 5
Views: 1253

os.system() in cgi script

I'm trying to get a simple cgi script running for a student (to call the example Pipsta printer programs from a web interface) and for the moment I don't see what's going wrong. In order to narrow it down I picked up an example cgi script from the net and modified it as follows: #!/usr/bin/python im...
by pleriche
Fri May 27, 2016 12:04 pm
Forum: Advanced users
Topic: /dev/video0 missing
Replies: 3
Views: 844

Re: /dev/video0 missing

PhilE: Err, yes. The camera had already been working fine with raspistill. dmesg | grep bcm2835 gave no relevant messages. But what idiot of a typographer ever thought it'd be a good idea to make a sans lower case L look so much like a figure one? Changed bcm2835_v412 (vee four one two) in /etc/modu...
by pleriche
Thu May 26, 2016 1:50 pm
Forum: Advanced users
Topic: /dev/video0 missing
Replies: 3
Views: 844

/dev/video0 missing

I have a webcam working fine using motion on a fairly old Pi running a version of Jessie on which I may not have done an apt-get update, upgrade recently, but trying to get it to work on another is defeating me. Both use directly connected Pi camera modules (not USB webcams). The difference seems to...
by pleriche
Fri May 13, 2016 9:00 pm
Forum: Troubleshooting
Topic: Samba problem on Jessie
Replies: 7
Views: 1791

Re: Samba problem on Jessie

OK, so (for the benefit of anyone sent here in the future by Mr Google), according to the smb.conf man page the server role parameter defaults to auto if not given, which causes Samba to determine the server role from the security setting. And the security setting defaults to user if not given, this...
by pleriche
Fri May 13, 2016 11:14 am
Forum: Troubleshooting
Topic: Samba problem on Jessie
Replies: 7
Views: 1791

Re: Samba problem on Jessie

Thank you, that's interesting and makes sense. But what doesn't make sense then is why the given smb.conf doesn't contain a security parameter at all, even commented out! However, I tried removing (with pdbedit) the Pi user entry which I'd added, adding security = user to smb.conf and rebooting, and...

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