PoKeys USB Interface

[Wendy]

Hello All,

Was out last night, so here I am.

@Thomas
For the LCD, it should be a HD44780-based character LCD. HD44780 refers to a kind of standard for these displays.
Led's need a resistor, that is correct. I did'nt know that it is not necessary with the CPFlight card.
For a overhead I have no idea how many you need.

@737NUT
No problem, hope you like the cards

@Hessel
It could be a replacement for the OC input/output cards and keyboard card if you have ProSim.
I have no experience with Level D so I cannot tell anything about this.


Regards, Wendy

[Wendy]

One card for free...

I'm going to give 1 card for free among all the orders I receive during the month of august 2011. Beginning of september an innocent hand will decide who get's his/her money back for 1 card (excluding shippingcost). I will publish the winner here in this thread.

Regards, Wendy

[tiburon]

Yes, bought mine for 59.00us! Sorry Wendy but the exchange rate is killing us thanks to the jerks in washington!

http://www.saelig.com/

How did you do that ? It will cost me 70 euro's and I live next door !

[Perik]

Wendy,

From the manual:

Digital output
Any one of the 55 pins can be configured as digital output by selecting ‘Digital output’ option box. Each pin can sink or source up to 4 mA of current, with the limitation that the pins combined source or sink current does not exceed 100 mA. If the polarity of the pin is inverted, check the 'Invert pin' box.

I may have missed something, but have you consider adding a driver circuit?
To me it seems as 10 LED's at 10mA each is a kind of a limit and
I believe that 4mA is too low for a well driven LED.

[Wendy]

What they mean I think is if you power it from the USB port because the USB port has a current limit. I'll ask the manufacturer but it was definitily more with my tests.


Regards, Wendy

[Wendy]

About the Led's...

Waiting for my answer I have setup a small test.

I have powered 1 led directly from PoKeys, the right one in the picture:
Output 3,1 Volt - Led with 330 ohm resistor - current flow 3,7 mA - 1,85 Volt over the LED.

Powered other outputs through ULN2803A driver, 3 leds bottom left:
PoKeys output goes directly to the ULN
4 Volt output from the ULN with 330 ohm resistor to the LED - current flow 6,8 mA - 1,95 Volt over the LED.

See the picture for the result. There is a small difference in brightness, the ones powered from the ULN are a little bit brighter, not much however.

Changing the resistor on the Led that is connected to PoKeys to 100 ohm gives me a current of 8,61 mA through the LED. Now I don't see any difference in brightness with the one powered by the ULN.







I'll come back on this as soon as I have more info.


Regards, Wendy

[Wendy]

Below is the answer from the manufacturer.
So the manual is correct.

Regards, Wendy


Hi!

4mA is maximum and from our experiences it is enough for modern LEDs.
If you need more current, you can use e.g. ULN2003 or ULN2803 to amplify it.

[Perik]

Hello Wendy,

Thanks for the verification.
My intention with the question was just to be sure about the 4mA/100mA
limitation so that people using the board for driving LED's install
an adequate resistor.

Anyway the board looks great, but one thing missing: SIOC support

[Wendy]

Hello Per-Erik,

In my setup I'm going to use the ULN2803A if I have to drive more leds from 1 port or if I need to use high current Led's. The ULN can sink 500 mA per port, I will probably never need that much current.



Regards, Wendy

[hexpope]

To us European customers, the price is only 50 EURO to your door from the main PoLabs website. I am going to order one today.