Raspberry Pi Forums

PiGraham

I just tried espeak and found a similar problem. The start is OK, but a few seconds in the speech slows and becomes Dalek-like - "slow and broken". I tried overclocking to medium setting to see if that had any effect, but it was no different. Flite (festival lite) works smoothly. I have no suggestio...

PiGraham

I haven't used it, but there is an Instagram API and you should find example code for basic authorisation and uploading. On my Canon DSLR, If I connect an external shutter release then closing the first contact (focus) wakes the camera from sleep almost instantly and it will last a long time in slee...

PiGraham

If you are really worried you could use an RGB LED and mix the colour spectrum you require. Just FYI, you can't do that. You can't control the wavelength of light from an LED (at least, not commonly available LEDs). All you can do is control the relative intensity of three different wavelength emit...

PiGraham

my aim is to make one that provides demonstrable results from something a builder who may be a young person is likely to have already, namely a camera or the Pi camera module. Have you seen the work the public laboratory is doing? Very similar, only with a tinge of an environmental focus: http://pu...

PiGraham

You might find Ardupilot interesting.

http://code.google.com/p/ardupilot/

PiGraham

jamesh wrote:The datasheet is wrong I'm afraid. According to the Omnivision engineer I spoke to, 90 is the max.

Oh well, never mind.

PiGraham

I've a datasheet that says it will do 320 x 240 @ 120 fps

I expect there a few science teachers out there, among others, who could make use of that.

It also seems the sensor can be windowed but it makes no difference to timing.

PiGraham

I don't believe we have incorporated that. And the Raspi only exposes one CSI-2 port anyway, so you can only attached one camera as standard anyway. Yes, but you can have more than one Pi. One possibly popular use case is stereo 3D camera using two Pis with cameras modules. You can do it without fr...

PiGraham

Don't get too excited. Windowed readout may not be possible on the Pi camera, it isn't important for what the camera is designed to do.Even if it's possible, it isn't likely to be something the foundation are going to devote resources to anytime soon. There are cameras around that do windowed readou...

PiGraham

Ah, got it. I should read posts more carefully before replying! Thanks for the mention of virtual wire. I see there is discussion of using it with Pi on the forum. http://www.raspberrypi.org/phpBB3/viewtopic.php?t=24215&p=225941 And follow-up here: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=3...

PiGraham

You may get some ideas here:
http://www.pjrc.com/teensy/td_libs_VirtualWire.html

Or here:

http://www.raspberrypi.org/phpBB3/viewt ... 5&p=225941

PiGraham

I see that the OV05647

Support for internal and external frame synchronisation.

Can anyone shed any light on that? Is it possible to frame-lock multiple cameras?
Is it possible to externally control frame rate or reset timing?

PiGraham

Is the Pi hardware capable of windowed readout? Some CMOS sensors can scan only a small ROI ar proportionately higher frame rates. If a Pi could produce video from, say 1k x 100 pixel ROI high frame rates might be possible.

PiGraham

Wireless may be possible. There are various 433MHz (I think doorbells will use 433) radio receiver modules available that could be connected to the Pi and may be able to detect the radio signal from the doorbell. You would have to experiment. Direct connection, via an opto-isolator, will be easier t...

PiGraham

It depends on the doorbell. Is it battery powered or mains powered? Is it a solenoid and chime type, or electronic? Do you have a multimeter? You should find there is a low DC voltage across the open contacts of the bell push. If there's a solenoid you have to take care of voltage spikes that could ...

PiGraham

Thanks guys, downloaded the 1 gig image, flashed it and it's now running. Shows up in the wifi hotspots lists and can connect to it, tho it seems I can't to send data to it yet somehow. I don't need to tweak anything with it right? (At least that's the feeling I had after reading the documentation)...

PiGraham

This might be a good starting point. http://www.adafruit.com/blog/2010/09/10/trashcan-accelerometer-using-the-adafruit-data-logger-for-arduino/ I'm sure you could get it much smaller and run it on button cells. How about this: http://www.adafruit.com/products/1247 with this: http://www.adafruit.com/...

PiGraham

How deep do you want to go? What interfaces do you need? 30m and no buttons is a lot easier than 50+m and buttons are difficult once pressure. Mineral oil will stop the pressure crushing the case, but I think its a bit more complicated than pouring oil into a box. Optical sensors inside a transparen...

PiGraham

I get it now, Thu is to design a crash-hat to protect a falling egg that will hit the floor. the idea is to measure how much the protection reduces the g-shock felt by the egg inside when it hits the floor, to aid deign of better protection. I originally read it as an egg catcher. Presumably it is i...

PiGraham

To estimate battery life calculate the battery energy in Watt hours rather than the current, and the consumption in Watts. A RasPi drawing a current of 700mA from a 5V supply is consuming power = 700 x 5 = 3500 mW. We have a problem with a specification of 11,200mAH for a battery pack. To calculate ...

PiGraham

It would be easier to measure the motion of the egg with optical or ultrasonic sensors. you could use the system with real whole eggs. There are some nice sensors out there, and you could even use a Pi camera.

PiGraham

Just a reality check. Are you doing this because it's fun / educational, or because you need to GPS track something? If all you need is to track something with GPS / GSM be aware there are devices around that do just that for about $40. Google "GPS tracker". There's nothing wrong with "reinventing t...

PiGraham

Has anyone who is raising concerns here contacted bitmit, a site filtering provider or even adafruit?

PiGraham

It's not banner adverts, it's auction listings, and it's on the boitcoin auction site linked from the Adafruit article. I saw a couple of listings for accounts on adult sites. They had small low res icons and titles like "1 year account xxxx.com" or "playboy.tv premium account". The icons I saw show...

PiGraham

The right hand circuit is almost certainly not operating as he thinks.... With +5V on the input the base-emitter and base-collector junctions in the 2N2222 are forward biased, the device is NOT acting as a transistor, but as a pair of diodes. Yep, a pair of diodes.Current will flow to the 3.3V rail...

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