LED Matrix

Testing/Troubleshooting
1

Hi 

Im currently Testing a 8x16 LED Matrix. I can’t find out why all the rows are lighting up simultaneously. 

 

the .NGC config is a simple test:

RESET_HW

LCD "%C"
LCD "@(1:1:1)OLED1"

# Test D-OUT LEDmatrix board

# Matrix control by a Encoder connected to DIN Board on Pin D0/D1
ENC n=1 sr=1 pins=6:7 type=detented2


DOUT_MATRIX n=1 rows=16 inverted=0 inverted_row=0 sr_dout_sel1=1 sr_dout_r1=2 sr_dout_r2=3

EVENT_ENC id= 1 fwd_id=LED_MATRIX:1 type=CC chn= 1 cc= 24 lcd_pos=1:1:2 label="^std_enc" LED_MATRIX_PATTERN=1

LED_MATRIX_PATTERN n= 1 pos= 0 pattern=0000000000000000
LED_MATRIX_PATTERN n= 1 pos= 1 pattern=1000000000000000
LED_MATRIX_PATTERN n= 1 pos= 2 pattern=1100000000000000
LED_MATRIX_PATTERN n= 1 pos= 3 pattern=1110000000000000
LED_MATRIX_PATTERN n= 1 pos= 4 pattern=1111000000000000
LED_MATRIX_PATTERN n= 1 pos= 5 pattern=1111100000000000
LED_MATRIX_PATTERN n= 1 pos= 6 pattern=1111110000000000
LED_MATRIX_PATTERN n= 1 pos= 7 pattern=1111111000000000
LED_MATRIX_PATTERN n= 1 pos= M pattern=1111111100000000
LED_MATRIX_PATTERN n= 1 pos= 8 pattern=1111111110000000
LED_MATRIX_PATTERN n= 1 pos= 9 pattern=1111111111000000
LED_MATRIX_PATTERN n= 1 pos=10 pattern=1111111111100000
LED_MATRIX_PATTERN n= 1 pos=11 pattern=1111111111110000
LED_MATRIX_PATTERN n= 1 pos=12 pattern=1111111111111000
LED_MATRIX_PATTERN n= 1 pos=13 pattern=1111111111111100
LED_MATRIX_PATTERN n= 1 pos=14 pattern=1111111111111110
LED_MATRIX_PATTERN n= 1 pos=15 pattern=1111111111111111

 

My diagram of the circuit shows the DOUTs that are connected to LED boards where all the Cathodes are parallel and the Anodes connected directly to the DOUT 2-3 as the example on the top left corner shows. 

 

post-10711-0-18942800-1428077778.png
post-10711-0-18942800-1428077778.png1200×810 200 KB

 

What am i doing wrong here?

 

Thanks for some help.

Best Regards

Novski

 

 

2

You need to set inverted=1 in the NGC when using an ULN:

 

DOUT_MATRIX n=1 rows=16 inverted=1 sr_dout_sel1=1 sr_dout_r1=2 sr_dout_r2=3

 

 

Another idea is to cut off the 5V of pin10. As far as I know pin10 should not be connected to anything (if I remember correctly in conjunction with a DOUT module).

3

Hi FantomXR

Thank you for the reply. I think i understand now. What happened is i connected the DOUT selection rows wrong. The first is the last and so on.

Because i didn’t have enough Headers laying around i tested just with two and didn’t recognize my fault because i didn’t see the last selection row glow when i tried to light up the first…

Now because i got the Meters light up with Inverted=0 but not with Inverted=2 i was searching for a failure always with a inverse working circuit. 

Have to redo my board or live with the inversed Matrix number…

Best Regards

Novski

4

Having pin 10 connected to +5v should not be a problem but removing it won’t hurt either.  This is normally connected to a +V and is used to snub the voltage spiks that occur when the outputs of the ULN2803 are connected to relays.  Since the outputs are connected to LED’s, it is not needed.

5

Thanks for making it clear!

6

Oh yeh. Now i understand the datasheet reference desing as well!

Thanks for pointing that out!