I'm planning to use a camera sensor to measure flicker from luminaries. In some environments there are many different luminaries with different flicker characteristics in the ceiling. Because of that I would like to use a cheap camera sensor to build a flicker meter that will create a heatmap of the luminaries.
I need frame rates up to about 50 kHz but the number of pixels of the image isn't very critical. Ov2640 has a throughput of 1600x1200 pixels @ 15 fps = 28.8 MPixels/sec, so given the same data rate I would like to use a cheap camera sensor to sample an image of 320x240 pixels. So if the frame rate is 50 kHz, I would typically fit 28.8e6/50e3=576 pixels in one window and then scan it for 50 000 times or so, then moving on to the next window until I have scanned the entire image.
I wish ov2640 could be used for this but from what I understand from the datasheet the frame rate doesn't depend on the window size. Does anyone know about a cheap camera sensor that can do this?
Why does it has to be a camera?
I'll use a photodiode attached to a transimpedance amplifier.
Optical mouse sensors are high framerate and low resolution, but I'm not aware of any that support reading the raw data at a fast rate.
Why does it has to be a camera?
I'll use a photodiode attached to a transimpedance amplifier.
I am using a photodiode in my current measurement device. However when I tried it in a store with 20+ different lights, it was hard to tell how much flicker came from each light source. So making an image of the flicker would be useful in my application.
Optical mouse sensors are high framerate and low resolution, but I'm not aware of any that support reading the raw data at a fast rate.
I think that will result in a too low total resolution. Still, I need a sensor of at least 320x240 pixels.
Ov2640 has a throughput of 1600x1200 pixels @ 15 fps = 28.8 MPixels/sec, so given the same data rate I would like to use a cheap camera sensor to sample an image of 320x240 pixels. So if the frame rate is 50 kHz, I would typically fit 28.8e6/50e3=576 pixels in one window and then scan it for 50 000 times or so, then moving on to the next window until I have scanned the entire image.
I wish ov2640 could be used for this but from what I understand from the datasheet the frame rate doesn't depend on the window size. Does anyone know about a cheap camera sensor that can do this?
It hasn't been since the single ADC CCD days that readout depended on the pixel count, CMOS image sensors are generally row based (but have many other constraints/configurations/paths).
50k FPS is getting off into very specialised devices. Is this a $100,000 device/job ? then time to redesign the concept.
What is the method that requires 50kHz? direct FFT of pixel data in time? What interest is kHz rate flicker?
Your overthinking it.
Undersample, or two cameras , or acousto-optic modulator in between the lens and ccd.
Steve