Laser Shutter Tester

RE: Laser Shutter Tester

khudam1971 — Tue, 01 Jun 2021 14:07:29 GMT

Hi! sokol07.I liked your project Laser Shutter Tester v2. 1 I want to repeat it for testing my camera.I have acquired the necessary material to repeat your project.Unfortunately, I can't program the Arduino Uno, it throws an error.Could you please help me in repeating your Arduino Uno programming sequence project.I will be grateful to you!

RE: Laser Shutter Tester

sokol07 — Tue, 19 Jan 2021 13:02:19 GMT

Again, thank you for you work and your feedback!

I saved your measurements and the suggested system. At the moment I have a bunch of stuff to do for my work and some urgent 3d printing for myself (tinkering in a little apartment sucks - i have space for only one project on the table...) but I hope i will be able to update the LST using your comments soon.

RE: Laser Shutter Tester

jc2048 — Sun, 17 Jan 2021 23:12:43 GMT

Nice project. I feel like I want to build one.

I don't have any TEPT5600 parts but I have some TEPT5700 [wider

viewing angle] so I thought I'd try them to at least get a rough idea

of what the speed was like [they don't necessarily have similar

characteristics, but it's possible they're the same die in different

packages].

This is with a 18k pull-up resistor to 5V. The light source is a

switched LED, positioned right in front of the sensor. The LED

switches fast enough that, on this scale, you can assume the light

intensity steps instantly at the trigger point (the 'T' marker at the

top of the screen). The timebase is 200us per division.

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[View:/resized-image/__size/480x234/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-4501d8c1-f442-45c1-94b3-06988c144247/contentimage_5F00_193528.png:480:234]

The output speed varies quite a bit with different values of resistor.

This was the value I needed to get the collector voltage right down

near zero when the LED is on.

It's not particularly fast, but then it doesn't need to be for the normal

intended applications. In your case, the two delays tend to counter

each other, at least to some extent. For this sensor, it looks like it

would be better with a TTL threshold than a CMOS one.

RE: Laser Shutter Tester

Fred27 — Sun, 17 Jan 2021 11:07:54 GMT

A very nice and well documented project!

I wonder if it would be worth checking the response of the phototransistor and the latency/jitter of your code by applying a pulse of a known width to the laser and checking the measurement you get is as expected? The project certainly seems to work well, but that might add some confidence that your measurements are accurate. I'm not familiar with the Arduino, but a lot of microcontrollers have hardware timers and interrupt-capable pins that could make time measurements more accurate and repeatable.

RE: Laser Shutter Tester

dubbie — Thu, 31 Dec 2020 11:52:37 GMT

I like it. I'll be sticking with my digital camera though.

Dubbie

RE: Laser Shutter Tester

neilk — Wed, 30 Dec 2020 17:31:32 GMT

Very nice project!

Neil

RE: Laser Shutter Tester

fmilburn — Mon, 28 Dec 2020 22:30:10 GMT

Nicely done!

RE: Laser Shutter Tester

genebren — Mon, 28 Dec 2020 21:58:11 GMT

Very nice setup. A very useful tool for checking shutter speeds.