Stefan,

I’ve tried using that same 16-channel 12-bit chip/board for LEDs too, but without much luck.

I forgot about the constant-current output part of the TLC59711. I had to go check my boards to see what I did when I used it with the PicoBucks. 🙂

I build little adapter boards with a 10K pull-up resistor on each of the outputs from the TLC59711 chip. I’m not an Electrical Engineer though, so I don’t know if that’s the best way to do it or not. Maybe Ethan will chime in with some advice. 🙂

Thanks for your reply 🙂
your board is in the shopping cart..

@Derek i will try this- i have the 16Bit board at my desk 🙂
how do you connected it? – the outputs of this are constan current if i remember right..

at the moment i have tested a design with a
RECOM RCD-24-0.35 (http://www.recom-international.com/pdf/Lightline/RCD-24.pdf)
in combination with
Adafruit 16-Channel 12-bit PWM/Servo Driver – I2C interface PRODUCT ID: 815 (https://www.adafruit.com/products/815)
i experimented with all possible combinations of different dimming options-
1. Analog
2. PWM
3. MOSFET PWM (short over led see example on page 4 http://www.recom-international.com/pdf/Lightline/RCD-24.pdf#page=4&zoom=170,-123,404)
if i have some time i will write collect the results and write it down..
i used only one 12-bit driver – this was set to 1kHz.
so my Analog Voltage was generated with a big RC-filter out of the 1kHz PWM….
Analog+MOSFET PWM is not working –
best result was to use PWM in high..midlow range
and for the low end use analog.
its a bit tricky to map this to a continuous ‘linear’ input range…

thanks for the nice work – i will test it out.

sunny greetings
stefan

I’ve been using these 16-bit PWM controllers from Adafruit:
https://www.adafruit.com/products/1455
for driving PicoBucks and have gotten really good low-end dimming.

The low-end dimming is surprisingly good. I have typically driven it with 8bit PWM so it’s a bit jumpy on the low end, but with 16bit PWM you will have really smooth low end dimming.

If you’re using an Arduino, just remember that the analogWrite() function typically does 8-bit PWM. You can directly write to registers and get 16-bit PWM working, or use a library.

how is the low dimming performance of this?
i am searching for a driver that can dim down to 0 without a ‘jump’ in the low end range..
my requirement is a single high-power led – 350mA (optional up to 700mA) – led forward Voltage is about 2V to 4V. (red.. blue/white)

second requirement for me is a simple design that i can build by hand soldering / were the components are easy to get in low quantities…
😉
if you have some tips on this let me know 🙂

i will order one of your designs by my next shopping tour by one of the SparkFun resellers..

sunny greetings

stefan

Nice work! Glad you were able to make good use of the driver IC, that looks like a really clean and simple design.

I promised a photo and failed to deliver – anyway – here it is finally. Coupled with a cheap source of RGB LED’s it became a nice little board.

https://twitter.com/SeismicStuff/status/494163774753218561

Thanks for the component inspiration!

And to give back something in return the RGB LED’s I found can be purchased reasonably cheaply on ebay from…

http://www.ebay.co.uk/itm/1000PCS-5050-3-Chips-RGB-SMD-SMT-LED-PLCC-6-20lm-/221185976642?pt=LH_DefaultDomain_0&hash=item337fb62942

Rgds,

Craig