Robo TX Training Lab (Hand Dryer Project)

[Mooki-Moo]

Hello,

I bought this (11 model) kit from Maplin Electronics the other day and this is my very first project build with FischerTechnik but I am having limited success with it. When I run the software for either Hand Dryer 1 or 2 the motor (fan blade) never stops as I assume it should.

My understanding of the project is that if the light beam being picked up by the photo transistor (PT) is broken the motor should stop. But in my build it never does. I have checked the wire connections with an Ohm meter and they are OK along with their port connections to the Controller, and the polarity of the PT is correct as well. So I don't know if the PT is broken or I am doing something wrong.

If I replace the PT with a Switch (and change the program as well) it will stop and start the motor as expected.

Any help would be appreciated.

[vleeuwen]

Did you choose the right input-mode for this Input?
digital 5kOhm (D 5k).
Did you connect the right polarity?
Red mark to the active input and the not-colored one to the gnd (ground)

For phototransistors ROBOPro sets the input mode to digital 5kOhm (D 5k). This way, you can use the phototransistor in conjunction with a lens lamp as a light barrier that is either interrupted (= 0) or closed (= 1). However, if you select the input mode analog 5kOhm (A 5k) for the photo resistor, you can differentiate between many shades of light and dark.

You can check the functionality inside RoboPro with "Test Interface".

[UMueller]

Hello,

I think you understanding of the function of an hand dryer is not that of fischertechnik :
The motor should run in case of the light barrier is broken (hand within the barrier).
In case 5 for five seconds. In case 2 as long as the barrier is broken.

Greetings Ulrich Müller

[Mooki-Moo]

Hi Guys,

Thank you for replying so soon.

vleeuwen:

The input mode is preset at D5K for this input and can't be modified.
The polarity is set with the red wire on the red mark on the PT and connected to the right input of I1 (next to the I1 legend)
When I select the "Test Interface" option if I click (to select) the check box for the I1 it instantly toggles from 0 to 1 back to 0 and removing the check mark.

UMueller:

Well that makes sense regarding the operation but makes my situation worse as the motor automatically starts after the 1 second delay. I thought it worked the other way to stop little fingers getting hit by the fan blade.

[UMueller]

Hello,

It seems to me, the lamp is not strong enough, did it have a lense?
Try it with the lamp very close to the transistor.
Try it with the interface test (menu)

Attention the manual changed Hand Dryer and temperture control
The motor only may start if barrier is broken : in your cause the lam is too low (may be?)
My actual test barrier works only in distance of 35 mm

Greetings Ulrich Müller

[Mooki-Moo]

Hello Ulrich,

Yes, the lamp does appear to have lens on it. It has a grey body with the other lamps I have having a white body.

I moved the lamp closer to the PT and it now works as expected. So that's that one solved.

For future reference how would I test it with the "Interface Test" option? I thought I'd already done that (see previous reply).

Yes, I agree, 35 > 40mm appears to be the operational distance.

[vleeuwen]

In the interface test you are able to see the value of the sensor inputs.
Switch to analogue and you will see the value changing when the light intensity is changing.
(not in the simulation mode but when the PC has been connected with an interface)

[UMueller]

Hello,

interface test : Menu View : Toolbar with Text
Symbol left from the 3 yellow ones

Greetings Ulrich Müller