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by davidmam
Sat Oct 14, 2017 7:50 pm
Forum: Graphics, sound and multimedia
Topic: Cirrus Logic Audio Card
Replies: 26
Views: 7970

Re: Cirrus Logic Audio Card

The Nyumaya card sounds intriguing. Will it support > 96kHz input. I want to record ultrasound (bats).
by davidmam
Mon Aug 08, 2016 8:58 am
Forum: Graphics, sound and multimedia
Topic: Bat detector
Replies: 28
Views: 25267

Re: Bat detector

I've been using the dodotronic mic with the Pi. It works fine but there is a catch. Arecord will not recognise the microphone as the recording frequency (250kHz) is too high. You need to change the code and recompile aplay in order to get ti to work. Yes, it contains a hard coded literal maximum for...
by davidmam
Mon May 16, 2016 4:43 pm
Forum: General discussion
Topic: Dedicated Serial Port in Raspberry PI
Replies: 24
Views: 3161

Re: Dedicated Serial Port in Raspberry PI

I've run into a similar issue trying to talk to some lab equipment. It requires DTR to be held high, and I'm not sure about CTS/RTS. Unfortunately the interface I have (The AB electronics one) is a rather minimal effort with just +ve/GND/TX/RX, though it has plenty of free connections to allow a cus...
by davidmam
Fri Oct 04, 2013 9:40 pm
Forum: Linux Kernel
Topic: PCM module (I2S) drivers?
Replies: 20
Views: 18628

Re: PCM module (I2S) drivers?

I'm wanting to integrate a high sample rate codec for recording ultrasound. I've got suitable microphones identified but am struggling on the 'turning it into sound' part. I'm looking at the TP3067 CODEC as it supports a suitably high sample rate but it has no I2C control (it appears to be quite dum...
by davidmam
Fri Aug 23, 2013 3:40 pm
Forum: Troubleshooting
Topic: USB issues - capturing useful information
Replies: 9
Views: 3661

Re: USB issues - capturing useful information

I have been using it successfully - I have some code at https://github.com/davidmam/pyCOSM in the examples directory.

I haven't looked at this for a while - I'll update the Pi firmware/distro etc and see how it runs over the weekend.
by davidmam
Mon Apr 01, 2013 12:50 pm
Forum: Troubleshooting
Topic: HDMI failure - is it hardware?
Replies: 6
Views: 755

Re: HDMI failure - is it hardware?

I tried multiple monitors. It was working until I tried the Plan9 distro (which may have no bearing at all on the situation).

..d
by davidmam
Thu Mar 21, 2013 10:01 am
Forum: Troubleshooting
Topic: HDMI failure - is it hardware?
Replies: 6
Views: 755

Re: HDMI failure - is it hardware?

I know the board was working with an older distro - it appears to have stopped doing so. I downloaded a new raspbian image and still no joy. Tried the hdmi_safe=1 and still nothing.
by davidmam
Wed Mar 20, 2013 11:30 pm
Forum: Troubleshooting
Topic: HDMI failure - is it hardware?
Replies: 6
Views: 755

HDMI failure - is it hardware?

I have two Pi, one is a ref 1 and the other a rev 2. The rev 2 has stopped working on HDMI. I can swap all the parts (card, psu, HDMI from the rev 1 (where it works) to the rev 2 and nothing - no output whatsoever. It has worked, but then just stopped. How can I test if it is the HDMI port? I can bo...
by davidmam
Thu Mar 14, 2013 2:12 pm
Forum: Other projects
Topic: Photography Projects
Replies: 150
Views: 61654

Re: Photography Projects

You could find the location using 'locate gphoto2' or 'which gphoto2'
by davidmam
Thu Mar 14, 2013 1:42 pm
Forum: Other projects
Topic: Photography Projects
Replies: 150
Views: 61654

Re: Photography Projects

You may have to set the permissions for the USB ports in order to run as Pi. Maybe create a camera group, add pi to that and make the USB port read/writeable by the camera group.

I'm sure a proper sysadmin will be along in a minute to explain how to do this properly.
by davidmam
Mon Mar 11, 2013 11:22 am
Forum: Other projects
Topic: Photography Projects
Replies: 150
Views: 61654

Re: Photography Projects

Superb. Now just need to wrap that fix in a define so it is configurable. ie. if (0 && (camera->port!=NULL) && (camera->port->type == GP_PORT_USB)) { becomes something like: (not a proper C programmer so this would need to be done properly) #DEFINE FIX_FOR_RASPI=0 if (FIX_FOR_RASPI && (camera->port!...
by davidmam
Mon Mar 11, 2013 9:22 am
Forum: Other projects
Topic: Photography Projects
Replies: 150
Views: 61654

Re: Photography Projects

Sounds good. Will I have to download the source and build from scratch or is there a raspbian package with the source?
by davidmam
Sun Mar 10, 2013 11:21 pm
Forum: Other projects
Topic: Photography Projects
Replies: 150
Views: 61654

Re: Photography Projects

That patch is not really fixing the problem but just working around the calls that trigger the problem?

Definitely worth a try.

..d
by davidmam
Wed Mar 06, 2013 8:01 am
Forum: Other projects
Topic: Photography Projects
Replies: 150
Views: 61654

Re: Photography Projects

Thanks for that, really useful. Have you passed this information on to the gphoto2 bug tracker or to the RPi USB developers? It surely would help them track down the specific issue. I might try using an EyeFi card for the transfer as that can do 'bottomless pit' storage (ie deletes the older transfe...
by davidmam
Tue Mar 05, 2013 9:19 pm
Forum: Automation, sensing and robotics
Topic: Lipo fuel gauge
Replies: 4
Views: 2106

Re: Lipo fuel gauge

Would that work with a hybrid solar/battery input, recharging the battery from solar?
by davidmam
Thu Jan 31, 2013 3:02 pm
Forum: Automation, sensing and robotics
Topic: Controlling solenoids with GPIO
Replies: 10
Views: 2447

Re: Controlling solenoids with GPIO

Sleep is independent of the pin settings. Think of True/False as two different settings on switches. Once it is set one way it will stay like that till you tell it differently. ie turn switch A to on. Wait ten minutes turn switch B to off. Switch A is still on all this time.. As for wires etc. you w...
by davidmam
Sat Dec 29, 2012 2:11 pm
Forum: Troubleshooting
Topic: HDMI stopped working suddenly
Replies: 7
Views: 1524

Re: HDMI stopped working suddenly

Any follow up on this? My Pi has jsut done the same - stopped working on HDMI (though I can SSH into it without bother). Edit: I've just checked the voltage on D1. There are three pins (which is sufficient to confuse me) On one side of the diode there are voltages of 4.97 and 0.00 (TP1 gives 4.97) O...
by davidmam
Mon Dec 24, 2012 12:11 am
Forum: Plan 9
Topic: GPIO with Plan 9?
Replies: 3
Views: 4939

GPIO with Plan 9?

How do you access the GPIO ports with plan 9? I would presume they are some sort of file somewhere (as is everything)
by davidmam
Thu Dec 20, 2012 11:24 pm
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 178694

Re: USB redux

Coming back into this - I have finally changed the wireless adapter to an Edimax one instead of the Ralink one and the Pi is subjectively more responsive and hasn't fallen over yet! We shall see how it proceeds.
by davidmam
Thu Dec 06, 2012 9:32 am
Forum: Scratch
Topic: Is Scratch really viable on Raspberry Pi?
Replies: 128
Views: 34963

Re: Is Scratch really viable on Raspberry Pi?

It would be great for it to include the GPIO interaction.
by davidmam
Sat Dec 01, 2012 11:13 am
Forum: Troubleshooting
Topic: Internal USB Hub resetting
Replies: 6
Views: 1148

Re: Internal USB Hub resetting

Can you measure the voltage between T1 and T2 on the Pi? It is entirely possible that you have a poor USB cable that is fine for data but not for power.

This is possibly one of the most common reasons for failure and should be the first to be checked.
by davidmam
Wed Nov 28, 2012 11:16 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: kernel patch for Dallas 1-wire interface
Replies: 227
Views: 144273

Re: kernel patch for Dallas 1-wire interface

Where can I find a list of supported devices? I would like to move my current greenhouse thermostat which uses DS2405 switches and DS1820 thermometers to Raspberry Pi. Will these work? Should do - just wire it in appropriately (to GPIO4 for data, a 4.7k resistor between that and +3.3v (pin 2), and ...
by davidmam
Wed Nov 28, 2012 11:13 pm
Forum: Python
Topic: write to GPIO in parallel
Replies: 11
Views: 3145

Re: write to GPIO in parallel

You could wrap the GPIO pin IO in a function that takes a bit string corresponding to the pins in question. Might have to be a bit fancy and include an element to include an indication of which bits should change. As a simple example assume 8 pins. PIN1HIGH= 1000000010000000 PIN1LOW= 100000000000000...
by davidmam
Wed Nov 28, 2012 9:03 pm
Forum: Scratch
Topic: Alpha testers needed for Scratch-GPIO control
Replies: 28
Views: 6148

Re: Alpha testers needed for Scratch-GPIO control

The GPIO interaction is what for me makes the Pi come alive and do what you can't do on a normal desktop computer. My son (10) has just finished making a reaction tester game (something I had done on an Arduino before) and programming it in Scratch. Now he is writing the script for the video. Two bu...
by davidmam
Mon Nov 26, 2012 10:14 pm
Forum: Troubleshooting
Topic: Power Issue Hell.
Replies: 16
Views: 1496

Re: Power Issue Hell.

The apparent strength of the cable is down to the plastic, not the wire. I bought some cheap (3 for £2) micro USB cables and I might as well have burned the cash. They cause a 0.4 V drop which is enough to screw the whole thing up. Fine for data, no good for power. It also caused me much frustration...

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