Sliding/Dimming LED PSU w/ RPi 3 & Blynk

Need Help With My Project
1

Hey everyone.

I’m trying to control the brightness/intensity of my LED lights through the Blynk application. While I’ve had success with the combination of the on/off button widget and a relay, I’ve come up short on the Slider widget.

Component Breakdown:

  • Raspberry Pi 3 +B
  • LED Power Supply Unit (PSU)
  • LED lights

So the Slider widget for the RPi 3 comes with one option for digital pinning, which is the GP18 PWM (pin 12). The LED PSU comes with a 3-1 dimming function, which allows the user to dim in multiple fashions, including PWM. Furthermore, the LED PSU comes with DIM+ and DIM- wires, which are separate to that of the V+ and V- wires, which connect directly to the LED lights.

As I have it:

GP18 PWM (pin 12) —> Dim+
Ground (pin 14) ----> Dim-

For whatever reason, nothing happens when I adjust the slider in this configuration. I’ve tried different GPIO cables but that doesn’t seem to be the root cause. Does anyone have any insight to share?

2

can you share the link / exact name / photo of the device?

1 Like
3

hey @vshymanskyy, I love what you guys are doing with Blynk.

What I recently noticed with the data sheet for the driver is that while it can be dimmed via PWM, it’s listed as being 10V. I don’t think the GPIO PWM pin for the RPi 3 +B is pushing that much potential but I could be wrong. If it’s not, and instead 5V, then that could possibly be the reason behind the dimming widget’s ineffectiveness.

Here is a link to the datasheet to the particular power supply that I’m working with:

Datasheet

On a positive note, I did have luck with the timer widget today.

Edit: The pages that pertain to this discussion are page 4~5 on the datasheet.