<snip>
anyway, my current setup is using a AAA battery for power.
so, my SFH5110 is correctly setup reading an output of 1.369V

but it doesn't go down at all when the IR led is on.
<snip>

1 AAA Battery is only roughly 1.5 Volts, if the SFH5110 requires a voltage of 5 Volts, then you are way off on the power requirements for the device. Try using at least 3 AAA's (roughly 4.5 Volts) and see if that makes a difference.

B. Morse

 

Well, one of your problems, is that the device isn't a phototransistor, it's a remote control decoder. It will output a train of pulses every time you press the keys on a remote control pointed to the device. You can check that if your multimeter has frequency reading.
The device you have will work with any remote with a 36 Khz carrier. I don't remember if that's a commonly used value.

 

You said the IR receiver IC gets hot. Then it was fried when you connected its pins wrong.
Replace it, connect it and drive it as shown on its datasheet.

 

1 AAA Battery is only roughly 1.5 Volts, if the SFH5110 requires a voltage of 5 Volts, then you are way off on the power requirements for the device. Try using at least 3 AAA's (roughly 4.5 Volts) and see if that makes a difference.

B. Morse

i'm pretty sure it should receive a voltage up to 5, and output roughly the same voltage until the IR light is one it.

You said the IR receiver IC gets hot. Then it was fried when you connected its pins wrong.
Replace it, connect it and drive it as shown on its datasheet.

I have a box of them, and got rid of the burned out one as soon as it happened.

 

Well, one of your problems, is that the device isn't a phototransistor, it's a remote control decoder. It will output a train of pulses every time you press the keys on a remote control pointed to the device. You can check that if your multimeter has frequency reading.
The device you have will work with any remote with a 36 Khz carrier. I don't remember if that's a commonly used value.

I see. So, it should work with a remote of the correct frequency?
if I use a function generator to make a 36kHz signal to drive the LED, what duration should I use for the signal to match a pulse from a remote control?

Is there another device that does the same thing, but is not limited in this fashion? I wanted something that was all in one device without a lot of external connections. This SFH5110 has a built in amplifier and everything and outputs the 5V I need without messing around. of course since I can't get it to work, I guess it isn't as great as I thought. and I realize it would be better if I could continuously shine the LED onto the receiver, and then detect when the beam is broken by blocking the LED. anyone know what i could use to do this?

 

something like this will work, does not need a modulated frequencey, but then, any ambient light will set it off....

B. Morse

 

i'm pretty sure it should receive a voltage up to 5, and output roughly the same voltage until the IR light is one it.



<snip>

You can not get the sensor to putout 5 volts if the input is only 1.5, it does not generate power to output the 5, it will only output a 5 volt signal if powered with 5 volts.


B. Morse

 

I see. So, it should work with a remote of the correct frequency?
if I use a function generator to make a 36kHz signal to drive the LED, what duration should I use for the signal to match a pulse from a remote control?

I'm not sure what will the receiver do. You could test it, maybe the receiver just gets rid of the 36KHz carrier, and you get a nice 5v output. But you must power the receiver with 5v supply if it says so in the datasheet.

 

IR receiver ICs must have the 36kHz IR carrier modulated by "'bursts of data". The datasheet tells how many 36kHz pulses are required in each burst and the length of the pauses between the bursts.

 

IR receiver ICs must have the 36kHz IR carrier modulated by "'bursts of data". The datasheet tells how many 36kHz pulses are required in each burst and the length of the pauses between the bursts.

thank you. I am looking at figure 3 of the data sheet now, and not understanding it very well.
it looks like 5 pulses, followed by a break, and then 3 more pulses should work. but i don't know if that break is important. the output signal in the figure starts after the first 3 pulses or so, and doesn't seem to shut off until after the pulses stop. that is, the first pause between pulses did not affect the output. is that correct?

what is duty cycle?

 

http://en.wikipedia.org/wiki/Duty_cycle

Have a read. It will explain duty cycle.

Basically it is the % difference between on and off.

 

All figure 3 is really saying is that there is a small delay between receiving the pulsed input and the detector switching its output low, a similar lag when it stops receiving. It is also showing that if it missed a pulse in the middle of a burst that that won't be enough to switch it off.

 

The Osram datasheet says in English: "A minimum burst length of 6 pulses is necessary for full sensitivity." The duty cycle is recommended to be 0.5 so the pause time between bursts of pulses is equal to the time of each burst.

For their TSOP series of IR receiver ICs, Vishay say there is a max of 70 pulses in each burst.

The output goes low during each burst then goes high during each pause between bursts.

 

For their TSOP series of IR receiver ICs, Vishay say there is a max of 70 pulses in each burst.

True, but it doesn't say that anywhere on the OSRAM datasheet, which is the sensor the OP is using.
I've used the TSOP parts made by Vishay and if you hit them with a continuous burst for as long as you want, the output stays low. For data transmission maybe this continuous burst may make it go outside some of it's specifications, but for object detection I think it would be fine.

 

The Automatic-Gain-Control in most IR receiver ICs turns down the gain if continuous pulses are received because they might be interference from a compact fluorescent light bulb.
Then the sensitivity is reduced a lot and it won't work unless the object is very close.

The Osram datasheet does not say enough details about their IR receiver IC.

 

I agree. There are various circumstances that should be addressed in the datasheet that are not.

Is there errata? Or an App note for it?

 

The Osram datasheet says in English: "A minimum burst length of 6 pulses is necessary for full sensitivity." The duty cycle is recommended to be 0.5 so the pause time between bursts of pulses is equal to the time of each burst.

For their TSOP series of IR receiver ICs, Vishay say there is a max of 70 pulses in each burst.

The output goes low during each burst then goes high during each pause between bursts.

so, my understanding is that if i have my LED driven by a 36kHz function generator, it needs to be sent in pulses for my thing to work. if I look at figure 3 on the data sheet, and imagine that there was no off time for the transmitter, then eventually, the output would return to high, right? But at least at first there would be a drop to low when the initial IR light hits the detector. BUT, i don't even see that. My output never changes from high when i shine the LED on the detector. I have the output going into a digital i/o board on a pc, so even if the change is very fast, i should still be able to see it to at least verify that my LED can trigger the thing.

should I just get a whole different setup at this point?

 

Yes, you should get a ir detector that is built for the task, rather than spending 100 hours of your time band-aiding this one.

If you value your time at say $10 an hour, you can set a 'give up' point for a project at which buying a off-the-shelf part or different part would save money in the project.