PoS080
Junior Member level 3
Hello EE friends,
I am working on an IR circuit using an IR photodiode and photoresistor. I want to pick up a LOGIC 1 if the phototransistor is ON and a LOGIC 0 if the phototransistor is off.
Currently I am using a LED attached between the emitter and ground to tell the state of the phototransistor, but I believe in my final design I should use a resistor for better control over the voltages. Please see the simulation image below of the on and off states of my circuit.
The left most circuit simulates my micro with which is running the IR diode. The middle circuit shows my current set up for the receiver circuit using an LED, and the right most circuit shows the receiver with a resistor instead of an LED.
My micro senses anything above 1.5 volts as a logic 1, I am picking up the signal at the blue nodes.
IRL, I do not get 5.77 volts at node '1' i get close to 0.45 volts.
V2 = 9 volt battery
My questions are
1. Am I picking the signal up at the right place?
2. Is there a better way to design for signal pick up?
**note to mods: I dont think this is a micro question, since I'm not asking about mircros but about circuit design for my receiver, but if this is in the wrong place I apologize in advance**
I am working on an IR circuit using an IR photodiode and photoresistor. I want to pick up a LOGIC 1 if the phototransistor is ON and a LOGIC 0 if the phototransistor is off.
Currently I am using a LED attached between the emitter and ground to tell the state of the phototransistor, but I believe in my final design I should use a resistor for better control over the voltages. Please see the simulation image below of the on and off states of my circuit.
The left most circuit simulates my micro with which is running the IR diode. The middle circuit shows my current set up for the receiver circuit using an LED, and the right most circuit shows the receiver with a resistor instead of an LED.
My micro senses anything above 1.5 volts as a logic 1, I am picking up the signal at the blue nodes.
IRL, I do not get 5.77 volts at node '1' i get close to 0.45 volts.
V2 = 9 volt battery
My questions are
1. Am I picking the signal up at the right place?
2. Is there a better way to design for signal pick up?
**note to mods: I dont think this is a micro question, since I'm not asking about mircros but about circuit design for my receiver, but if this is in the wrong place I apologize in advance**