Individually switched leds and dimming

[StyxF2]

Hi All,

I have a circuit as in the attached pic. Each of J2 pins 1-8 are switched with 28V, activating each led individually. Additionally, theres a 'test' switch on J1 that will light all the leds as the same time to test them.

Im looking at a method to dim all these leds (together, not individually) for low light conditions, while when the test switch is pressed, they all display at full brightness. The dimming is going to be controlled by a 0-12V signal. Im thinking the best way is to find an MCU with 8pwm outputs, hopefully supplying enough current to run all the leds (Or switch them with a transistor if not), and ADC for the dimming input and GPIO for the test switch

However does anyone know of any options that could run this without an MCU and code?

[drvtech]

You could take the common point of the LEDs to ground through a transistor and apply a pwm waveform to that and then override it with the signal from the test button.

[StyxF2]

thanks drvtech!! that worked a treat, not sure why i ddint see it, but very happy it works!