Haven't immersed myself into proximity sensors much, so I do not know the possibilities. I am looking to achieve the following:

Problem:
The new microwave is a pain in the ___ to see the buttons on. It's black with gray or light gray type and is next to impossible to see in dimly lit places.
During the day there is a lot of reflection from a window opposite the microwave and in the evening or later, it's really not visible.

Solution (1):
No, turning a room light on is not a solution! Not one I am entertaining.
My thoughts are to attach(via a magnet) a simple LED light to the top of the microwave pointing at the keypad. A simple test has proven to be an excellent solution. But I do not want the light to be on all day/night. So my thoughts drifted to a sensor. A motion detector would work, but is far too bulky.
The next possibility is a IR proximity sensor. I will likely have a 5V supply to operate both the sensor and LED(s).
The intention is to be able to place your hand on or near the keypad and the light comes on. Additionally, the light needs to stay on for 5s-10s and then turn off.
The sensor I found that seems small enough is pictured below:


Information and datasheet HERE!

Essentially, I just want to float this by you so that I might get some aditional ideas/solutions/alternative parts that I might not already be thinking of.

 

Check the standby power of sensor, power supply, timer etc. It may be more power-efficient just to keep a low-powered LED light on permanently.

 

I would go with something like this.

https://www.allelectronics.com/item/led-td/led-touch-dimmer-module/1.html


Or something like this to trigger a 555.

https://www.allelectronics.com/item/se-61/metal-touch-sensor/1.html

 

Check the standby power of sensor, power supply, timer etc. It may be more power-efficient just to keep a low-powered LED light on permanently.

Standby current of sensor is in the uA, but with IR LED's ennabled it is about 8mA. The LED's setup I have will be (2-4) 20mA White LED's(40ma-80mA) I an experimenting just what lighting requirements will be acceptable.

As far as keeping the light on for 5s-10s, the info states that the signal will be on as long as motion is being sensed...not sure if it turns off immediately when motion is not sensed though. It uses the MIC1557 IC, which is very similar to the 555 timer.(believe it is mainly for setting freq. @ 38kHz.

I would go with something like this. At this point I could go one step further and just add a switch to the LED's light! In other words, this is just a glorified on/off switch.
https://www.allelectronics.com/item/led-td/led-touch-dimmer-module/1.html

This is in the realm of possibility, but requires user intervention to turn on and off. At this point I could go one step further and just add a switch to the LED's light! In other words, this is just a glorified manual on/off switch.

 

"The intention is to be able to place your hand on or near the keypad and the light comes on"

Meets your basic requirements...

 

"The intention is to be able to place your hand on or near the keypad and the light comes on"

Meets your basic requirements...

Yes, it did meet my initial "basic" requirements.

Didn't you read the fine print?

Disclaimer: this whole thread is really a "thinking out loud" post.
Requirements are subject to change without notice.
Notice: Must be functional without user intervention!! HeHe

 

If using the OUT pin from this TSSP77038 sensor as input to a 555 timer, It should work, yes? It sits high until a signal is detected and then goes low, which triggers the 555 in monostable(one-shot) mode.

Description of the TSSP77038 IR Sensor:
The OUT pin, which is high by default, remains low as long as the TSSP77038 receiver is detecting a sufficient signal. When at the edge of the detection range, this output will alternate between high and low. A red LED on the emitter side of the board is tied to this output and turns on when the pin goes low, providing a visual indication of when the sensor is detecting something.

I may use a MIC1555 IC(timer) as a low Quiescent current device/timer. Anyone have a ballpark figure for current consumption on the lowest 555 timer iC?

 

Pick the convenient flavor
----> https://www.aliexpress.com/wholesale?SearchText=motion+sensor+lamp&opensearch=true

 

https://www.amazon.com/gp/product/B06Y5G27G6/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

 

https://www.amazon.com/gp/product/B06Y5G27G6/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Interesting parts. Seems that I may run into issues with the sensor turning on every time I walk through my kitchen. Plus I am not a fan of ICStation as they ripped me off ant did not replace three bad parts I purchased from them.

 

Will stick to my "design" for the time being and post a working/non-working circuit when I can.

 

Ah, just worked it out.
The original reference to "microwave" must be the "microwave oven", not some exotic microwave proximity sensor.
Torch?
What's entertaining got to do with it? Surely can't be so engrossing to have to go to such lengths.

 

I know its a complete cheat.. but:
https://www.aliexpress.com/item/VOP...lgo_pvid=ad659b3f-4250-4b01-89bf-697425062c9c

They are actually very handy, come in lots of shapes and sizes and have excellent battery life.