K8088 strange output

Hi all
I am currently converting a Transit van to a camper and the plan is to use a pair of k8088s to control self assembled led rails made from rgb leds (4 legs). I’m currently prototyping in my front room with a supply at 12.3v. I have both common anode and cathode leds

placing a volt meter across the outputs gives the following results:

Input voltage 12.3v
Red, green, and blue +/- gives no voltage
input - to red - gives me 3.4v
input - to green - gives me 4.5v
input - to blue - gives me 4.5v

input - to all + outputs gives me 12.3v

I have managed to get a common cathode rail working by connecting input - and rgb -s but I am unable to get common anode leds to work (as stated in the manual).

any ideas what might of gone wrong?

also does anyone know if you can perchance the pic chip separately as I have blown the blue channel in the prototyping first kit? (second kit yet to be built)

cheers
Dave

It is hard for us to get an exact idea of what you are doing but anyway, a couple of remarks:

  1. K8088 will not work with CC led. Impossible.
  2. RGB leds require a series resistor for each colour. Either you mount them on the K8088 board or you mount a wire jumper on the board and you provide an external series resistor.
  3. A spare PIC can only be supplied if the defective item is returned.

I am building LED rails of 36 LEDs using strip board, LEDs are in parallel

I understand what you are saying but It has worked, I can only assume that I’ve done something wrong when building the kit, What are the expected output voltages If the kit was correctly built?

the CC LEDs are connected with common to input (-) and the rgb connected to the rgb (-) Voltage readings are betwenn 3.5v to 4.5v

all RGB outs (+) are reading the input voltage (12.3v)

resisters added on the board.

Where do I send the defective chip?

cheers
Dave

Please note that you cannot put leds in parallel.
Leds in parallel require a series resistor for each colour of each led.
A single series resistor on the board will not work.
See: http://www.vellemanprojects.eu/downloads/0/information/engineering%20note_uk.pdf

You can return the IC to:

Velleman Kit Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium