So new week and new parts coming in.


DPD brought last components for my light controllers, TC4424A non-inverting power fet controller chips. Results looks so far pretty good. I have been running demo program I wrote for Arduino now few hours and the fet heat sinks are cold. And I do not mean bit warm, they are cold enough that I’m expecting the fets running on these loads without heat sinks just fine. Well this patch of the controllers can keep ‘em.


The light from that strip is nice. The 5050 LEDs are bright enough and the controllability is sensitive. I’m sure that these gives me just fine general light as soon as I get it all set up. It seems like a good time to start ordering some more LED-stripe.


First things first. I need to get the firmware of the bedroom Arduino set for controlling first set. The test program was just under 6kB which will be tight squeeze. Hopefully the fact that current firmware has all the basics imported already will save me up the space just enough to get it fitting in. Then of course altering Cizilo to provide me controls over network for those lights.


The TC4424A is nice chip. 2 channels and power consumption is almost non-existing. 1kOhm trimmer as voltage divider (IRF520N can take only 10v as gate voltage) gives enough power through to keep the driver working. No singing circuits/cables, no flickering and they were really easy to set up. I just put 4.7microF tantalum and 100picoF ceramic capasitors after the voltage divider and 1000 & 470microF + one of those ceramic 100picoF caps on the 12V power line on the circuitboard as well. 4k7 Ohm pull downs from inputs to ground and rest was just wiring the driver outputs to the fets and the fets to the LEDs.


I need 2 of these drivers for each led strips to cover all three colours. meaning I have one channel unused. Now as it seems that I do not need the heat sinks for the fets I might try to push these on single 5x7cm circuit boards. Other option is that I keep the layout I have with the first patch and leave the one side of the second board to seat Arduino Nano. It would fit perfectly and provide pretty neat package. Leonardo and Nano can both drive two sets of these controllers.


As a result for today I have HW set for a while and I need to focus the software side.


Lets see if I finally tomorrow get some pictures out. Now it’s time to get some sleep.