Sign in to follow this  
Guest sfleron

FSLED Problems please help

Recommended Posts

Hey GuysI'm new at this forum - but have been reading for a while. I started FSBUS a week ago, and have build the COM, FSKEY and FSLED.I'm now stuck at the FSLED, it just will not work for me. I read a lot of postings about the 33 pF capasitors not being correct, so I checked this - no problems found. I checked the board for shortings - no problems.Here's what I do know:1) FSCOM is OK, as I have flashed the FSKEY, and FSKEY works perfect2) Not a cable issue, I'm using the same cable for FSLED as I did for FSKEY3) I can flash the PIC on the FSLED board - When reading it back it looks good.4) When I measure the power on the board I find 1,5V on the LED???5) I have tried the DO/LED Test in FSBUS, but nothing happens.6) I have not seen light in any of the LEDS so far.Please help, as this is REEEEEAAALLLYYY bugging me.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

A (possibly) dumb question, but did you connect the leds the proper way? Cathode to the common ?1.5V at the led output is about right. You don't need more.George DorkofikisAthens, Greece

Share this post


Link to post
Share on other sites

Hi GeorgeYes I'm sure, there are none connected yet - I'm still just testing the outputs of the board. The output for the LED is constantly 1,5V, no matter what I do - even with the LED test program is FSBUS.Please help...Could anybody please give some points on the board to measure voltage... I really checked the board, and can't find any errors...Best regards Soren

Share this post


Link to post
Share on other sites

Try to find any short-circuit you have done by mistake!!Also take care there is some short-circuits you must done, they appear with red color in pcb layout.I think as the PIC programming work fine, the problem maybe is after the PIC to the area and components where you attach the LEDS regardsEddie ArmaosAthens-Greece

Share this post


Link to post
Share on other sites

Hi EddieThanks for your answer.I have tested the board, trying to find a short somewhere, but I just can't find any...What should the voltage be for a LED?I flashed the PIC with CID 20 and then flashed it again with another CID - is that OK - are the PICs RE-flashable?Are there any other places on the board where you could provide me voltages that I can measure out?I'm really stuck - please help.ANY help is very welcome...

Share this post


Link to post
Share on other sites

>Hi Eddie>>Thanks for your answer.>>I have tested the board, trying to find a short somewhere, but>I just can't find any...>>What should the voltage be for a LED?When i use the Do/LED test and give power to an empty position i get 1,22V Maybe this is the reason that Dirk suggest 4k7 for a better led brightness>>I flashed the PIC with CID 20 and then flashed it again with>another CID - is that OK - are the PICs RE-flashable?MAny many times, but not unlimited :-)>>Are there any other places on the board where you could>provide me voltages that I can measure out?>>I'm really stuck - please help.>>ANY help is very welcome...It's a simple PCB, i don't know how else i can help you :-(If there is no short-circuits and you cannot find the solution, don't stay and loose your time!! Make a new one! I had the same problem with a FSBus Com which was asking too much power (about 15v input) to flash the PICs and after some months of serach without found the reason, i made a new COm and it works fine!!Eddie ArmaosAthens-Greece

Share this post


Link to post
Share on other sites

Hi Soren,I have the same problem of you.Flashing the LED controller is ok but no leds working.If i test the output with a tester it shows me 1.5 V ALWAIS, no matter what random test is doing.I don't know what to do Dylan

Share this post


Link to post
Share on other sites

I'm sure this is a really, really silly question, but are you checking the voltage right across the pair of contacts that you'd fix an LED to? The positive side should have a voltage if checked to a common ground or earth - the transistors on the ground side complete the circuit by opening the negative side of the LED to ground. Richard

Share this post


Link to post
Share on other sites

Hi Richard,i just checked better and i found no voltage across the contacts of the led and 1,2 V constant on the base of each transistor, independing from test.Any advice?ThanksDylan

Share this post


Link to post
Share on other sites

I forgot to say i have 3105g transistor instead of bc337 but they told me it's an equivalent also in pin position.Dylan

Share this post


Link to post
Share on other sites

Dylan,Try one more thing. Flash the PIC again but this time use an ID like 8 or 9. The voltage of 1.2-1.5V is ok for the LEDs. You may want to change the 33K resistors that drive the transistors to 4.7K to increasethe current.Also, did you use normal LEDs for your tests? Did you connect any to see it it lights up ? Just measuring the board won't tell you much because it works like a matrix sending on/off pulses to the LEDs one at a time in high frequency sequencing. The LEDs may APPEAR on at all the time, but they are not. It's how you actually see them as the eye can't catch anything faster than 30Hz.George DorkofikisAthens, Greece

Share this post


Link to post
Share on other sites

Hi George,I tested and there is no voltage at led output while there is a constant 1.2 volt at every PIC out before each resistor 33k. I tried with one led but no light, i also tried to reduce to 4k7 the resistor in base of BC337 and nothing.I assigned a CID 8 and then 10.I really don't know what to do.ThanksDylan

Share this post


Link to post
Share on other sites

Thanks for all your help guys ;-)I will run over it once more, and then see if I can get it going, if not, I will build a new one...I am measuring the voltage with no LED attached...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this