Timeline for Controlling individual LED strips of different kinds and lengths with a single microcontroller
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 5, 2017 at 18:33 | vote | accept | zhulien | ||
| Aug 5, 2017 at 16:46 | comment | added | bobflux | Also the FET has 16 mOhm with Vgs=4.5V so it will dissipate 0.4W @ 5 Amps, really reasonable. No need for a heat sink at all, make sure the enclosure has airflow, although the power supply fan should take care of that... | |
| Aug 5, 2017 at 16:31 | comment | added | bobflux | The board is nice if you don't feel like making a board yourself and soldering the SMD, otherwise just the chip ;) | |
| Aug 5, 2017 at 13:11 | comment | added | zhulien | Thank you very much for the assistance you provide. So, finally, I'm thinking of going with the 2x PCA9685 + 17x IRLB8721. I hope this will sufice. However, can I get the PCA9685 chip only or do I need the whole board from Adafruit? | |
| Aug 5, 2017 at 12:17 | comment | added | bobflux | well, the datasheet says "programmable frequency from a typical of 24 Hz to 1526 Hz" so 1600Hz sounds right... The oscillator is internal to the chip so probably not very accurate, but that's not important here. | |
| Aug 5, 2017 at 11:33 | comment | added | zhulien | I was just looking into the driver and its documentation. However, I'm a little concerned about the consistency of the documentation: 1. Library reference: learn.adafruit.com/16-channel-pwm-servo-driver/…. 2. Example code: github.com/adafruit/Adafruit-PWM-Servo-Driver-Library/blob/…. The library reference says that the max frequency is 1000Hz, the example code states that it's 1600. Considering there are 2 public methods in total that need to be documented, this kinda bothers me. | |
| Aug 5, 2017 at 11:02 | comment | added | bobflux | I'd go with an I2C driver which outputs PWM and can drive the MOSFETs directly, like PCA9685 or other, for simplicity. Also adafruit has breakout boards and example code. adafruit.com/product/815 | |
| Aug 4, 2017 at 10:57 | comment | added | zhulien | I am actually open to any solution that gets the job done properly, I'm not bound to a specific driver or method. What solution would you go with if you were on my place? | |
| Aug 4, 2017 at 7:47 | comment | added | bobflux | I never used TLC driver so cant be sure. You can always try cdn-shop.adafruit.com/datasheets/PCA9685.pdf instead, datasheet says it goes from 0 to 100% PWM, and it can drive logic level MOSFETs directly (see "external mosfet" in datasheet) | |
| Aug 4, 2017 at 7:22 | comment | added | zhulien | I read somewhere that the TLC driver don't enable the channel completely i.e. don't/can't lighten the LED completely to its 100%. If I invert the signal, wouldn't there be a problem with the driver not being able to shut off the LED completely? Which solution do you recommend. I'm fairly new to electronics and I'm better off not taking this decisions myself. Also, can you please explain me why is the pull-up resistor for in this case and how it inverts the signal exactly. 2. Should I drive the mosfet gate from 5V or 12V? 3. What value should I use for the pull-up resistor? | |
| Aug 3, 2017 at 16:42 | history | answered | bobflux | CC BY-SA 3.0 |