Data Comms in the 'off' period of PWM

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this popped up on Twitter:

https://twitter.com/hackaday/sta...

 

When they say, "two-wire" sensors, they're not talking I2C - it's more like 1-wire (plus ground)

 

Reference: https://hackaday.com/2021/12/04/two-wire-sensors-on-led-strips/

 

 

I'm sure it's not new, but nonetheless a clever technique.

 

Not limited to just LED strips, of course.

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Wow, very clever method of sending low voltage comm's during the Off Phase of the 24 V PWM signal.

 

At first I wondered why the 10 mA current hack on the output of the accelerometer, as an opto-isolator would have been the trivial solution to link the accelerometers PWM data to a micro.

Then I realized that the accelerometer is likely sitting at the far end of the LED string, not back at the power supply and the primary PWM driver for the LED string.

 

That, therefore, earns the designer bonus points for a double great hack!

 

JC