[fecal_henge]

To reply to this and the above comment:

Cheapest light pipe on digikey: 16 cents Cheapest photodiode on digikey: 11 cents Cheapest LED (obviously that annoying blue): 625 milli cents!

Part costs matter! Its not just the BOM, its the NRE from the increased complexity. Im not saying saying its OK, just that its inevitable considering the economic conditions.

I do board level designs and drop down LEDs. If you are not specialising in indicators, its hard to visualise how bright 10mA through your diode is going to be. Add to this that sometimes you never even see the thing you designed!

[godelski]

  > 16 cents Cheapest photodiode on digikey

On DigiKey the cheapest is $0.125[0]. On Alibaba I can find much cheaper, including less than penny [1,2]. Now pretend with me that you're building in lots. You're going to get cheaper than Alibaba, though maybe not by much.

  > I do board level designs and drop down LEDs. If you are not specialising in indicators, its hard to visualise how bright 10mA through your diode is going to be.

I think if it is annoying enough that at presumably >10m away it can keep the gp awake you don't really need to be that precise in your measurement. It's basically way too bright.

But if you want to get creative you could use the diodes in the circuit or even your led if you'll blink it. But that last one doesn't tell you the led brightness, only ambient.

[0] https://www.digikey.com/en/products/detail/harvatek-corporat...

[1] https://www.alibaba.com/product-detail/1-4V-20-30-45-60_6253...

[2] https://www.alibaba.com/product-detail/JST3-3MM-receiver-pho...

[fecal_henge]

The digikey costs are more (I quoted qty=1 prices though), its the ratio between the component types which is more interesting though.

I think annoying at 10m is sufficient power to require a 'power' LED, so that shouldnt be hard to avoid in a design I would agree. Annoying in your kitchen however is much harder to eyeball a value for (excuse the pun).