Raspberry Pi Forums

richrarobi

This might help: https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=13883 Also this is interesting reading: https://learn.adafruit.com/reading-a-analog-in-and-controlling-audio-volume-with-the-raspberry-pi/overview or: http://www.raspberrypi-spy.co.uk/2013/10/analogue-sensors-on-the-raspberry-p...

richrarobi

Assuming you ran ssh from a system running X, (rather than one of those M$ thingies) as in this example from my Linux Mint to pi system a:- ssh -l pi -Y a.local the -Y is important (or use -X) note the uppercase. See https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=11833&p=728951&hilit=pcmanf...

richrarobi

may not be relevant, but fom a quick google.....

Make sure PHP has permission to excecute that file.

richrarobi

Quite by chance, I found this:-
http://projectpi.org.uk/tag/nanpy/
There is an example of analogue write in the first section of code. NB, though, that this all uses an old version of Nanpy.
RichR

richrarobi

It's a bit difficult to read your code because it isn't in a "code" block - notice that joan's post did this and it has all the indentation replicated. However:- You are using threading. If you were to switch to multiprocessing, you would have each process running in its own process and able to run ...

richrarobi

From a g**gle, it appears that with a basic stepper motor it isn't possible. You need some kind of extra physical end-stop (end of carriage on a plotter, or 3d printer?) . Suggestion is to count the steps and return to that point. Not perfect, but seems that's it. This might help: http://www.explain...

richrarobi

I don't think it is totally a good idea to power your arduino's from the pi - if you start driving things off th arduino's the power drain will mount up. You should consider separate power direct to the power ports of those arduino boards. Maybe a powered usb hub would be enough to isolate the pi ? ...

richrarobi

I haven't looked at nanpy (or arduino) for a while - they aren't very good at documenting their interface (API) - They seem to think we are telepathic - Anyway after half an hour I found this - https://github.com/nanpy/nanpy/blob/master/nanpy/arduinoapi.py line 29 hints at the answer - analogRead - ...

richrarobi

To add to the previous note, there is a guide for installation of SDR-J on the pi :
http://www.michaelcarden.net/

It works, after some fiddling with the config file - read the comments on the post.

p.s. It is suggested that at least a PI2 is needed.

richrarobi

Static ip's can be a pain in the..... Another way to go might be to use avahi .... from one pi to another, or from any system supporting bonjour/avahi to another (i.e. I use Ubuntu Linux) ssh -l pi -Y d.local where d is the name of the connected host, Note the .local once you have connected using th...

richrarobi

probably worth looking at this thread:- https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=46881&p=839460&hilit=nanpy#p839460 To begin with consder the pi as the pc in control of the arduino.. i.e. install the arduino software on pi. sudo apt-get install arduino After trying some sketches (to c...

richrarobi

Single threaded, i.e. sequential operation.
You need to investigate threading or multiprocessing so that your timed code can run separately.

richrarobi

Not sure exactly of the whole answer.... I set up espeak on a pi2, and had all those messages, and sound didn't work. Found a note somewhere that PulseAudio was the CAUSE, solution was to remove PulseAudio (sudo apt-get remove PulseAudio). It still didn't work. I tried espeak on a B+ that I knew had...

richrarobi

Sorry, missed that second link, 'cos I didn't read it (I worked with (VAX) clusters (many) years ago and won't go there agin... Wasn't disagreeing with your sentiment, just that I think that there are so many confused people about .... They seem to get so excited about clusters and they don't know j...

richrarobi

Clusters are a great way to learn about Distributed Computing, it will not become a Super RPi.... I don't think fruitoftheloom entirely intended the 'Distributed' in the statement above. Apart from that one word I totally agree..... However, Distributed Computing is what many of the fun things in I...

richrarobi

This might help (from a quick Google) http://stackoverflow.com/questions/4960048/python-3-and-mysql Stick at it, Python2 is fading (slowly, but it has an end of life plan, I believe) Python3 is better documented, etc, etc. I decided to use python3 throughout, sometimes it is quite frustrating that c...

richrarobi

The serial port (two pins on gpio) should work as a second connection - this post has some info (around nanpy and arduino and serial ports) (but be careful of voltage differences)
viewtopic.php?f=44&t=46881&p=839460&hilit=nanpy#p839460

richrarobi

Ideally, use RPC see viewtopic.php?f=31&t=123977&p=1029741#p1029741

You might find that calling the other system using SSH works for you.

richrarobi

Had the same problem, found this treasure: http://pythonhosted.org/astral/
Works for me ...
Any use?

richrarobi

http://raspberrypi.stackexchange.com/qu ... pplication

richrarobi

What is it about networking you think is unreliable?
Seems like a shame not to use the best components that are designed for the job?

richrarobi

I want to write a program in Python to start activity (a measurement) on the RPI and retrieving the data, stored in the RPI, to my PC. You might find what you need in something like mqtt, or zeromq - messaging solutions. What you describe does tend to look like you need an RPC style answer (or even...

richrarobi

Times have definitely changed, however I believe the (defence) industry had a core of knowledgeable programmers, also...Two sides to every fence...Nothing personal... and we were getting along so well... deleted CV....Official secrets....18 yrs at Ferranti.... In those Ferranti Computer Systems days...

richrarobi

I don't (normally) get into C, but I did wonder if the columns could look better!! As for KISS, I guess we can :oops: say goodnight to that (to put it more politely than I first typed . . . ) For my mind, if you (or even I) can't read it without a code book (aka Bletchley Park) - it isn't good code....

richrarobi

Although with my simpler mind I would prefer the following test line :

Code: Select all

if (c % 8 == 0)

(it does maybe need cnt to be +1)
p.s. My compiler seems to prefer c to be an int for the printf statements....
p.p.s. Does the original "design" intend the stray '0' at the start of the column?

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