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IR phototransistor to 8051

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abuza8nuqina

New Member
I'm trying to detect the presents of foods in my cats food container using an IR phototransistor which then the signal will be fed to my 8051 for refilling purpose.

This is my plan. Will it work? (if not, what do i need to modify?)


My plan was to use 8051 pin1.2 to detect the high & low. If the pin detects a HIGH, then refilling will be done automatically. Otherwise it wont.

Comments & critics is highly appreciated.

Thanks,
BARRI
 

ccurtis

Well-Known Member
You should connect the left side of the bottom resistor to Vcc instead of to the LED. Then you will have a better high than the mere 1.2V from the forward voltage drop of the LED.
 

Sceadwian

Banned
As it is it won't work, the phototransistor will pick up ambient room light as well as the LED, if sun directly hits the bowl it'll likley over fill it pretty bad. You'd have to use an modulated light source and only trigger when that was received. Something like an IR remote module would work pretty easily, just use the 8051 to send a pulse every few seconds to check to see if the receiver see's anything.
 

Sceadwian

Banned
Yep, that's the idea. The 8051 would be used to generate the frequency the IR detector needs for a brief period every few seconds, when you star receiving pulses on the IR receiver you know you have a signal.
 

abuza8nuqina

New Member
Yep, that's the idea. The 8051 would be used to generate the frequency the IR detector needs for a brief period every few seconds, when you star receiving pulses on the IR receiver you know you have a signal.
ok Sceadwian, thanks you so much for your help & guidance. I really appreciate it! :p
 

rushi53

Member
I'm trying to detect the presents of foods in my cats food container using an IR phototransistor which then the signal will be fed to my 8051 for refilling purpose.

This is my plan. Will it work? (if not, what do i need to modify?)


My plan was to use 8051 pin1.2 to detect the high & low. If the pin detects a HIGH, then refilling will be done automatically. Otherwise it wont.

Comments & critics is highly appreciated.

Thanks,
BARRI

I can't see the images
can you please upload them again ?

from your description it looks like logic is okay... just take care of hardware connections and programming
 
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