Go to advanced search

by hystrix
Mon Sep 08, 2014 4:11 pm
Forum: Graphics, sound and multimedia
Topic: Bat detector
Replies: 28
Views: 29085

Re: Bat detector

Hi keviom, The amplitude, or intensity, of the calls can be seen in the sonogram since it is represented by the intensity of the colour. What is of interest is the peak frequency, which can easily be analysed using Audacity. Here's a Common Pipistrelle from one of my recordings, and the peak frequen...
by hystrix
Fri Aug 22, 2014 5:36 pm
Forum: Graphics, sound and multimedia
Topic: Bat detector
Replies: 28
Views: 29085

Re: Bat detector

Hi Nick,

The external microphone is an electret type, with a high frequency response.

The software I use is a mixture of Audacity for initially extracting bat calls from the wav files, and producing sonograms, plus BatExplorer from Elekon for sonograms and analysis.
by hystrix
Sun Jun 08, 2014 10:27 am
Forum: Graphics, sound and multimedia
Topic: Bat detector
Replies: 28
Views: 29085

Re: Bat detector

I had some success recording bats this week-end with my Pi and Wolfson audio card!

Details of my Pi Bat recorder and sonograms can be found here:

http://www.afraidofsunlight.co.uk/weath ... p?page=bat
by hystrix
Mon Apr 28, 2014 11:37 am
Forum: Graphics, sound and multimedia
Topic: Bat detector
Replies: 28
Views: 29085

Re: Bat detector

With the release of the Wolfson audio card for the pi audio recording at 192kss is now easily do-able. I have recorded some pipistrelles in the garden with frequencies so far recorded up to around 65kHz. This is using the on-board DMIC microphones. Having the odd occasional problem of overruns on r...
by hystrix
Wed Mar 05, 2014 5:35 pm
Forum: Camera board
Topic: RPi Cam Web Interface
Replies: 5139
Views: 1447751

Re: RPi Cam Web Interface

hystrix wrote:I would like to have a button on the web interface to reboot my Pi (to restart RaspiMJPEG in case it has crashed for some reason). Is this possible?

I would be grateful if someone could give me an indication about how to do this.

Many thanks.
Can anyone help me with the above?

Many thanks.
by hystrix
Thu Feb 27, 2014 5:09 pm
Forum: Camera board
Topic: Trigger video capture from another Pi
Replies: 6
Views: 2106

Re: Trigger video capture from another Pi

I think you may be able to use an SSH library to send a signal... See http://jessenoller.com/2009/02/05/ssh-programming-with-paramiko-completely-different/ Caveat: I haven't tried any of this! I tried this approach, Pi1 had a PIR trigger and a camera with a direct view, Pi2 is distant with a teleph...
by hystrix
Wed Feb 26, 2014 6:59 pm
Forum: Camera board
Topic: Trigger video capture from another Pi
Replies: 6
Views: 2106

Trigger video capture from another Pi

I have one Pi that is monitoring an IR beam (monitor Pi). When the beam is broken, I would like a camera Pi connected to the same network as the monitor Pi to start capturing video.

Does anyone have an elegant solution to this problem? I can think of some clumsy ways of doing it.

Many thanks.
by hystrix
Tue Feb 18, 2014 7:14 pm
Forum: Automation, sensing and robotics
Topic: DHT11 Data pin voltage
Replies: 5
Views: 3284

Re: DHT11 Data pin voltage

I have just tried it - I put 20k Ohm between the Data pin and Ground, so with 10k Ohm between Data pin and Vcc (5V) I get 3.33V on the Data pin. It seems to be working OK... Date/Time Temperature in Box (°C) Humidity in Box (%) 18/02/2014 18:26:13 8 68 18/02/2014 18:36:21 8 68 18/02/2014 18:46:30 7 ...
by hystrix
Tue Feb 18, 2014 1:15 pm
Forum: Automation, sensing and robotics
Topic: DHT11 Data pin voltage
Replies: 5
Views: 3284

Re: DHT11 Data pin voltage

Can I use a 20k resistor between the data pin and ground as a voltage divider to get the pin at 3.3V?
by hystrix
Mon Feb 17, 2014 7:46 pm
Forum: Automation, sensing and robotics
Topic: DHT11 Data pin voltage
Replies: 5
Views: 3284

DHT11 Data pin voltage

I have a DHT11 Temperature/Humidity Sensor connected to 5 metres of wire. ( I read in a datasheet that the maximum wire length when using a supply voltage of 3.5V is 20cm, otherwise measurement errors occur). I am powering my DHT11 from 5V (GPIO pin 2) and I'm using a 10k pull-up resistor on the dat...
by hystrix
Fri Feb 14, 2014 2:42 pm
Forum: Camera board
Topic: RPi Cam Web Interface
Replies: 5139
Views: 1447751

Re: RPi Cam Web Interface

I would like to have a button on the web interface to reboot my Pi (to restart RaspiMJPEG in case it has crashed for some reason). Is this possible?

I would be grateful if someone could give me an indication about how to do this.

Many thanks.
by hystrix
Fri Jan 17, 2014 5:41 pm
Forum: Wanted
Topic: Bat study - technical help wanted -
Replies: 16
Views: 4927

Re: Bat study - technical help wanted -

Hi David, Did you get a solution to this? I would be interested in helping, but unfortunately not before end of February. I realise your need for this timescale, but I have only just found your post. I think by this time next February, a robust solution could be in place (these things take time, esp...
by hystrix
Mon Dec 30, 2013 10:46 am
Forum: Camera board
Topic: RPi Cam Web Interface
Replies: 5139
Views: 1447751

Re: RPi Cam Web Interface

Nice bird pictures! The RPi camera web interface 'talks' to raspimjpeg using a pipe, located at /var/www/FIFO by default. If you do echo 'ca 1' > /var/www/FIFO raspimjpeg starts recording a movie and echo 'ca 0' > /var/www/FIFO stops it again (see https://raw.github.com/silvanmelchior/userland/mast...
by hystrix
Sun Dec 29, 2013 4:10 pm
Forum: Camera board
Topic: RPi Cam Web Interface
Replies: 5139
Views: 1447751

Re: RPi Cam Web Interface

This is an excellent project. Many thanks for sharing. I currently operate a Pi based trail camera with PIR motion sensing to capture still images and a video of pre-determined length (e.g. 40 seconds). (Details here: http://www.afraidofsunlight.co.uk/weather/index.php?page=trailcam ) Can someone gi...
by hystrix
Sun Sep 01, 2013 12:29 pm
Forum: Camera board
Topic: Raspberry Pi Trail Cam - first day results...
Replies: 11
Views: 13052

Re: Raspberry Pi Trail Cam - first day results...

Is this the PIR sensor you used ? http://proto-pic.co.uk/pir-motion-sensor-1/ Gordon77 Yes, that's the type. There are cheaper ones available if you shop around, although some do not come with leads. I used standard female/female jumper wires as these plug straight onto the GPIO and the PIR Sensor.
by hystrix
Tue Aug 27, 2013 11:37 am
Forum: Camera board
Topic: Raspberry Pi Trail Cam - first day results...
Replies: 11
Views: 13052

Re: Raspberry Pi Trail Cam - first day results...

Yes - I am using mains and a long (weatherproof) lead. I did experiment with solar power and batteries, but it was not reliable enough unfortunately.
by hystrix
Mon Aug 26, 2013 7:17 am
Forum: Camera board
Topic: Raspberry Pi Trail Cam - first day results...
Replies: 11
Views: 13052

Re: Raspberry Pi Trail Cam - first day results...

Here's an update showing some photos of the construction, and latest videos captured using the Pi Trail Cam...

http://www.afraidofsunlight.co.uk/weath ... e=trailcam
by hystrix
Mon Jul 29, 2013 11:54 am
Forum: Camera board
Topic: outdoor enclosure for RPi + camera?
Replies: 11
Views: 35426

Re: outdoor enclosure for RPi + camera?

I squeezed a Pi, camera board and PIR Motion detector into a smallish plastic enclosure from Maplin. See this post... http://www.raspberrypi.org/phpBB3/viewtopic.php?f=43&t=49337&p=384183#p384183 It is not a waterproof box, but I sealed it with camouflage Gorilla tape. Due to the size of the power s...
by hystrix
Mon Jul 08, 2013 11:55 am
Forum: Camera board
Topic: Raspberry Pi Trail Cam - first day results...
Replies: 11
Views: 13052

Raspberry Pi Trail Cam - first day results...

I thought I would share some results from the camera module..... Using a Raspberry Pi, camera module and PIR sensor and a Python script, I have built a trail cam to monitor a perch I have placed above a small stream at the end of my garden. When motion is detected it grabs 2 high resolution still im...
by hystrix
Mon Jun 10, 2013 6:29 pm
Forum: Camera board
Topic: Lightweight python motion detection
Replies: 259
Views: 280961

Re: Lightweight python motion detection

piabpiab wrote:
Are you using ctrl-x to stop rather than ctrl-c?
Erm...yes. ctrl-c works fine :)

Many thanks!
by hystrix
Sun Jun 09, 2013 10:37 am
Forum: Camera board
Topic: Lightweight python motion detection
Replies: 259
Views: 280961

Re: Lightweight python motion detection

This is a really good bit of code! I have run into a problem when I stop the code (e.g. to make an adjustment to sensitivity) and then try to restart..I get the following error: Traceback (most recent call last): File "motiondetect.py", line 69, in <module> image1, buffer1 = captureTestImage() File ...
by hystrix
Fri May 31, 2013 1:42 pm
Forum: Python
Topic: Python - turn wifi on and off
Replies: 6
Views: 11819

Python - turn wifi on and off

I plan to have a solar/battery powered Pi with a camera module and PIR motion sensor working as a trail camera in my garden. I would like to be able to send any images captured by email, but to conserve power, I would like to be able to turn wifi on, connect to my home network, send the email with t...
by hystrix
Sun Feb 03, 2013 12:30 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 195
Views: 79750

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

I have finally got my Rev2 Pi receiving data! :D I'm sure I need to do a bit more tweaking....I'm not consistently reading transmitted data (many minutes between successful data received), and also have quite a few crc fails.... Pulse stats: Hi: 702 - 995 Lo: 1015 - 2179 (88 point) Data bits = 88 (o...
by hystrix
Sat Jan 26, 2013 3:55 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 195
Views: 79750

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

... when I try to run the executable using ./weatherlogger , I get the following errors: Failed to open /dev/mem, try checking permissions. Failed to map the GPIO registers into the virtual memory space. It's most likely just file permissions - look at the output of 'ls -l /dev/mem'. If you run the...
by hystrix
Sat Jan 26, 2013 2:00 pm
Forum: Automation, sensing and robotics
Topic: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi
Replies: 195
Views: 79750

Re: Fine Offset WH1081 (Maplin N96GY) sensors working on Pi

... when I try to run the executable using ./weatherlogger , I get the following errors: Failed to open /dev/mem, try checking permissions. Failed to map the GPIO registers into the virtual memory space. It's most likely just file permissions - look at the output of 'ls -l /dev/mem'. If you run the...

Go to advanced search