Raspberry Pi Forums

davef21370

Thanks for the info, I think the hearing aid batteries may be the way to go, cheap & light, no need for rechargeables, one shot job. (don't be a troll... this has been hashed out ad nauseum on this forum) I wasn't being lazy, trust me, I've googled this to death and couldn't find a suitable solution...

davef21370

I do have a very small, very cheap LCD display that I can use but then I'd need a means to control the Pi (start/stop video

Buttons on the GPIO, loads of examples available.

Dave.

davef21370

What's the smallest and, more importantly, lightest way to power the RPi for 5 minutes max?
Model A+ with camera, low current GPIO output and no other peripherals.

Dave.

davef21370

Bit of a shot in the dark but http://en.wikipedia.org/wiki/Nagle%27s_algorithm , maybe you need to send more data or disable the delay... Applications that expect real time responses can react poorly with Nagle's algorithm. Applications such as networked multiplayer video games expect that actions i...

davef21370

The leading underscore denotes an internal function and calling it should be avoided. Also (and I'm ready to be corrected) if you were to use from SomeModule import * any functions with the leading underscore wouldn't be imported. As for the settings, once you have an instance of the camera class, i...

davef21370

http://mattrichardson.com/Raspberry-Pi-Flask/
Possibly the easiest way to put output from Python into a web page.

Dave.

davef21370

Have you tried this route https://www.abelectronics.co.uk/i2c-ras ... /info.aspx ?

Dave.

davef21370

What format is the data from your compass module?

Dave.

davef21370

Have you tried the basics... https://www.raspberrypi.org/learning/ge ... worksheet/

Dave.

davef21370

You need to create the file "act.txt" then write the date/time data to it.
Do a bit of googling about python and files, you'll find loads of examples.

Dave.

davef21370

Should it not be rcv = worksheet.readline() ?

Dave.

davef21370

Google numpy-stl

Dave.

davef21370

Have a look here https://www.pygame.org/docs/tut/newbieguide.html and read about dirty rect animation. This only updates areas of the screen that have actually changed instead of updating the whole thing.

Dave.

davef21370

@scoty101: thank you for that link.. Do you think this could be used with the beaglebone? I mean is there something like this for the beaglebone connected to the MCP23017? You're more likely to get the answer on the . B E A G L E B O N E . forum This is the . R A S P B E R R Y . P I . forum! This i...

davef21370

I will pretty much guarantee that nobody will write this code for you. It's not terribly complicated but will take up a fair amount of someone else's time and effort so here's my advice... Use PyGame if you just need to display a big circle, loads of examples online. Get to grips with the graphics a...

davef21370

Not familiar with the RPi 2 pins and can't tell much from your picture but I think you need to decide between BOARD and BCM pin layout. Google GPIO.setmode and see if that helps.

Dave.

davef21370

What error do you get?

davef21370

Firstly just an observation if classnumber==int(1): fname = 'class2.txt' should that be class1.txt? Anyway, SQL would be the normal way to go as what you're making is a simple database. However, if this is an exercise in learning Python you may be better creating a class (not a school class, a Pytho...

davef21370

As much as I like Arduino (especially the Nano) I'd be tempted to leave it out of this project and just have the Pi reading the temperature. This may help https://www.cl.cam.ac.uk/projects/raspb ... mperature/

Dave.

davef21370

Try Googling bitstring, that may help.
Dave.

EDIT python bitstring

davef21370

Put a small delay in your loop to free up some processor time.
http://www.tutorialspoint.com/python/time_sleep.htm

Dave.

davef21370

As already suggested sack the PIR's. Stick with the HC-SR04's, they have a range of up to 4 metres so assuming you're not batting along at 40 knots they should give you ample time to respond. Now just to complicate things further (it's actually not that bad) might I suggest using an Arduino Nano to ...

davef21370

Thanks all, I have a MOSFET knocking about somewhere (something 540) so I'll try that.

Dave.

davef21370

gregeric wrote:I'd recommend you use a MOSFET instead of a junction transistor.

I'm using PWM (980Hz max) to control the LED's, will a MOSFET be able to switch fast enough?

davef21370

This isn't strictly a Raspberry Pi question as the project is now using an Arduino Nano but I'm programming it through the Pi so fair's fair. I've currently got the board flashing and flickering several LED's (separate pins) and it's working as expected. Now I want it to do the same with strings of ...

Search found 897 matches

Re: Very short term power supply

Re: Good/best way to remotely control a camera?

Very short term power supply

Re: UDP sending via python

Re: how to use _get_camera_settings() in picamera module

Re: Python variables to web page in real time

Re: ADCPi Plus from ABElectronics

Re: Autonomous boat: Auto compensate the rudder?

Re: Minecraft Python

Re: give variable as name

Re: NameError: name 'port' is not defined

Re: Importing of 3D STL Image

Re: Flickering in pygame using HWSURFACE

Re: Generating a pulse signal in tkinter

Re: refreshing rate

Re: dt11 is not detecting on raspberry pi 2

Re: Storing data from Python program to MySQL database

Re: How to display 3 latest results from text file in Python

Re: DS18b20 rx on pi

Re: Reading a single bit from a serial port in Python.

Re: Running a script

Re: Autonomous Boat Project

Re: Transistor selection

Re: Transistor selection

Transistor selection