Help using teensy to read led status of powerboost

[dbak85]

So I am working on an Idea and I have gotten a little stuck need some help from the Gurus out here.

I am currently using a teensy to drive a neopixel for my status light. I am currently using a modified version of @Camble's power monitor script to change the status of the pixel. When the Pi is on it sends sets a pin to high that the teensy reads and sets the light at amber.

When the script detects low battery status, it sets a second pin to high and the pixel goes red. this works fine.

Now I have a powerboost running all this. All the grounds are tied together on all the components via the powerboost. I have read the specs of the powerboost on where to pic power for external leds, but I just want to read the status of them from the teensy. With the grounds tied together, measuring from the powerboost ground to all the led points seems to produce between 3v and 5v wherever I check and whatever the state of the led.

I am not sure how to proceed. I thought of using a Light Dependant Resistor to get the values, but there are loads of little lights on all the components that would cause bleed, so I would need to make special cones to isolate the LDR from the rest of the leds and it ids pretty awkward to get to work.

I was wondering if anyone out there could help me figure out how I am supposed to correctly get a signal from the powerboost led? I know I am doing something wrong.

[HoolyHoo]

So I am working on an Idea and I have gotten a little stuck need some help from the Gurus out here.

I am currently using a teensy to drive a neopixel for my status light. I am currently using a modified version of @Camble's power monitor script to change the status of the pixel. When the Pi is on it sends sets a pin to high that the teensy reads and sets the light at amber.

When the script detects low battery status, it sets a second pin to high and the pixel goes red. this works fine.

Now I have a powerboost running all this. All the grounds are tied together on all the components via the powerboost. I have read the specs of the powerboost on where to pic power for external leds, but I just want to read the status of them from the teensy. With the grounds tied together, measuring from the powerboost ground to all the led points seems to produce between 3v and 5v wherever I check and whatever the state of the led.

I am not sure how to proceed. I thought of using a Light Dependant Resistor to get the values, but there are loads of little lights on all the components that would cause bleed, so I would need to make special cones to isolate the LDR from the rest of the leds and it ids pretty awkward to get to work.

I was wondering if anyone out there could help me figure out how I am supposed to correctly get a signal from the powerboost led? I know I am doing something wrong.

You could do something like this from the LED point itself. Ignore the rest of the circuit, the important part is the 2n3904. So when the Powerboost lights the LED it should close the circuit for the signal that you need.

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[dbak85]

I got so caught up in thinking about various voltages etc that I never thought of using a transistor.

That is a great idea! I will start investigating thanks!