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ToyKeeper / anduril

Anduril 2 Flashlight Firmware and FSM UI Toolkit
GNU General Public License v3.0
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Question: Can someone explain Aux brightness levels? #44

Closed fiveseven808 closed 6 months ago

fiveseven808 commented 6 months ago

So, I'm under the understanding that AUX lights aren't PWMed to achieve the lower brightness because that would keep the MCU awake.

I can't find any schematic for any light showing the AUX leds other than just some lines off of the MCU dedicated to them.

I assume they're driven directly off of the MCUs output lines through a resistor for "high"? But it's unclear to me how we're able to get the second "low" brightness level.

Can someone explain this to me?

Reason for asking: I want to bridge the resistor on the RED AUX channel on a D4v2, and I want to know if I'm gong to fry the MCU or affect the "low" aux value, and if so by how much?

SammysHP commented 6 months ago

I assume they're driven directly off of the MCUs output lines through a resistor for "high"?

Correct.

But it's unclear to me how we're able to get the second "low" brightness level.

The MCU contains internal pull-up resistors. For the low mode it is enabled in series with the external resistor.

I want to bridge the resistor on the RED AUX channel on a D4v2, and I want to know if I'm gong to fry the MCU or affect the "low" aux value, and if so by how much?

The low mode won't be affected much, the high mode could damage the aux LED and/or the MCU.

fiveseven808 commented 6 months ago

Thank you, that clarifies a lot. Looks like I'd need to replace the resistor for what I want to do.