fischertechnik community forum

Verfasst: **15 Sep 2021, 14:32**

Hi all,

I already had an ft color sensor and I ordered a second one from the same seller. This seller has semi-new fischertechnik parts from old schools stock, but she doesn't know much about the parts themselves. I noticed that the LED and the phototransistor/photodiode look different from what they should look like, and the LED is white instead of red. Also the wires come from a single hole in the casing. Look at the photo below, the unknown sensor is on the right:

: Two sensors.jpg (68.35 KiB) 3726 mal betrachtet

I can't tell anything about how the sensor reacts I didn't test it yet, I just lighted up the LED. The ft database does not mention another part number either (I looked for "Farbsensor").

Is this an old version of the color sensor? Is this a color sensor at all? Any help would be much appreciated.

Thanks,

Rubem

Verfasst: **20 Sep 2021, 18:21**

Hi again,

No ideas about this sensor yet? Well, I decided to make some quick tests with the two different sensors and got some interesting results. Here is my test setup, where you can already see a few parts of the pinball table I'm building:

: test setup.jpg (88.12 KiB) 3585 mal betrachtet

The sensors are driven by a 9 V power source and their outputs are attached to an Arduino Nano. Here's the relevant code:

Code: Alles auswählen

loop() {
  Serial.print("Red LED: ");
  Serial.print(analogRead(A6));
  delay(50);
  Serial.print("    White LED: ");
  Serial.println(analogRead(A7));
  delay(50);
}

"Red LED" and "white LED" are just a way to refer to the two sensors (128599 and unknown, respectively) according to their LED colors. I used two distances for the measurements, 15 mm (a block) and 4 mm (the 31982 spring cam you can see in the above picture). Then I copied some typical values to a spreadsheet and plotted the results to a line graph:

: data.png (74.25 KiB) 3585 mal betrachtet

Lower values mean more luminosity. The very high values were obtained by illuminating the sensors directly with a 3-color flashlight. Even with my inherently very imprecise measurements, it seems that the unknown sensor — which is symbolized by the blue lines — has a very different response curve from the "normal" sensor with the red LED. Its range of values is not so useful, the curve falls very abruptly and there is an obvious non-linearity with the red hues. I still hope I can use it to detect the steel ball, however. Otherwise I'll have to use yet another non-ft sensor for it (I already use several).

Still want some ideas, especially if someone has some experience with this uknown / older sensor.

Regards,

Rubem

Verfasst: **20 Sep 2021, 20:10**

Hi,
There is also the typical color sensor for Arduino, how does it behave with this one ?
https://www.reichelt.de/arduino-farbsen ... KyzfD_BwE

Br,
Frank

Verfasst: **20 Sep 2021, 21:14**

Hi Frank,

Thanks for your suggestion. I can't say much about this particular sensor because unfortunately I don't have one. I do have an APDS-9960: https://learn.sparkfun.com/tutorials/ap ... okup-guide. It is an ambient light and RGB sensor with gesture and motion sensing capabilities. However the APDS-9960 is incredibly sensitive to ambient light because it does not have a LED of its own. Probably the one you refer to would do a better job, no doubt. For the rest of my project I'm using the ubiquitous QRE 1113 which is ultra small and does not react much to ambient light.

Best regards,

Rubem

Verfasst: **22 Sep 2021, 21:16**

Rubem, why do you need color detection in a pinball game ?
Are there any colored balls

Br,
Frank

Verfasst: **22 Sep 2021, 22:19**

Hi Frank,

FrankHGW hat geschrieben: ↑
22 Sep 2021, 21:16
Rubem, why do you need color detection in a pinball game ?
Are there any colored balls

No, not really. I use regular 12.7 mm steel balls that are identical to the ones that come with the Electropneumatics kit. The color sensors (which are in fact luminosity sensors) are used only to detect the presence of a ball. I used the color objects only to compare the responses of two types of sensors. Thanks for helping me clarify this point!

Anyways, it's strange that I seem to be the first to report about this odd-looking sensor with a white LED. It does not even have a part number of its own. ffm also does not have it, "Farbsensor" gives just the regular sensor. Could it be part of a small, old production batch?

Best,

Rubem

Verfasst: **23 Sep 2021, 18:48**

Hi Rubem,

unfortunately I can't write anything about the color sensors, because I don't own any.
So with you it serves only the ball detection - that reads interesting;-)

I am curious about your pinball machine, when it is finished.
Then please post a photo here.

Br,
Frank

Verfasst: **23 Sep 2021, 19:08**

Hello Frank,

FrankHGW hat geschrieben: ↑
23 Sep 2021, 18:48
I am curious about your pinball machine, when it is finished.
Then please post a photo here.

Sure. There are still quite a few things remaining, it's a very complex project. I'll certainly create a new topic about it (with pictures, of course) when it's finished.

Thanks for your interest!

Rubem

Verfasst: **23 Sep 2021, 19:13**

You could open the sensor and have a look at the PCB inside. It may carry a vendor name or the like.

Verfasst: **23 Sep 2021, 19:18**

Hi MoG,

MasterOfGizmo hat geschrieben: ↑
23 Sep 2021, 19:13
You could open the sensor and have a look at the PCB inside. It may carry a vendor name or the like.

Good idea. Actually I already kinda tried to pry it open but it doesn't come off that easily

I don't want to break anything... I don't really know if there is some method to safely open the case.

Thanks for the idea, though.

Best,

Rubem

fischertechnik community forum

Zwei Arten von Farbsensoren? / Two types of color sensors?

Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?

Re: Zwei Arten von Farbsensoren? / Two types of color sensors?