I am having made some small breakout boards for the PCA9685 chip. This is a NXP chip is in a TSSOP28 package with 0.65mm spacing so it is a bit hard to prototype with which is why I am having to make some boards. These are single sided and are suitable for soldering pins on for directly plugging into a soldererless bread board. The have space for surface mount current limiting resistors or a link as well as address setting links by using solder blobs. And of course space for a surface mount decoupling capacitor.
I am looking to see if there is anyone who would like to have some of these boards. The price would be £2.50 each plus P&P at cost. Payment by PayPal. I need to have an idea of the demand so I can order the right number. If you are interested then reply to this thread or PM me. Also for any questions about this or the chip then reply here.
About the PCA9685 One chip will directly drive 16 LEDs @ 20mA with 4096 levels of brightness by using PWM. Each LED requires it's own current limiting resistor in a current sinking mode. It is easy to add FET drivers to drive more or bigger LEDs. There are six external address lines making the total limit of 64 of these chips on a bus at one time. That's 16 * 64 = 1024 individually controlled LEDs before you have to bother with bus switching. Being I2C it is easier to site these remotely from the arduino than the TLC5940 and you can get I2C drivers to extend the range of the bus. There is total flexibility about the on time and off time of the LEDs so you can arrange things to minimise current surges by not having all the LEDs come on at the same instance, although they will appear to so. Software control is easy and I have already written functions to show how this works.