I am using K8064 DC controlled dimmer, actually together with K8055 USB experimental interface, which works really fine. The only problem I have is, that I want to be able to increase the brightness of a usual 230V/60W lightbulb very, very slowly. Unfortunately, at the low brightness end, there are quite discernable “steps”, i.e. one can see the brightness making a “jump”. These jumps do not stem from the K8055 - i can increase DA output by several steps before I see a jump and can also see voltage increasing. It more looks like the AD-converter on K8064 is only 4bit or something like that. Is there any way to improve on that?
Unfortunately this cannot be changed.
Do you have the same problem when you apply a DC voltage (e.g. from an adjustable power supply) to the input of the dimmer?
Yes, the effect stays the same even if I use a true analog input voltage. Saying it is only 4bit is exaggerating, but still the steps are clearly there. Is there any possibility to re-program the PIC with other TRIAC-triggering points? In the upper brightness range fewer steps would be OK, if I could have more steps in the low brightness end.
I can understand this. Perhaps I’ll do a bit of “reverse engineering”
Just one more question attached to this topic: I currently run K8055/K8064 in the following way:
[ul]
[li]Analog input of K8064, (+) attached to +12V power supply[/li]
[li]Analog input of K8064, (-) attached to PWM1 of K8055[/li]
[li]GND of K8055 attached to GND of Power Supply[/li][/ul]
Would you recommend to add a capacitor as low pass filter in order to smoothen the PWM output?
As I already said, my idea was to do some reverse engineering. I bought K8048 in order to have a look on the uC on the dimmer board, thinking this my personal introduction into the uC-programming world. Guessing from this post: http://forum.velleman.eu/viewtopic.php?f=6&t=2471&hilit=k8064+steps%20 I thought I might find the TRIAC triggering points in the PIC data and modify them. Unfortunately my assumptions seem to be worng and I learned that there is something like PIC “code protectection”, making any reverse engineering virtually impossible.
So my question is: Is there any way to change the behaviour of the dimmer by modifying the not protected data section of the PIC, or is my only option to write my complete own program for the uC in order to change dimmer behaviour?
