OK..now I am really confused. I noticed something which has completely baffled me. Here is what I observed.
I DISCONNECTED my Arduino from the computer and did NOT give it any additional power.
I just wanted to check the voltage that I was getting on my receiver output with a multimeter.
Now this is what happened, when I let light fall on the photodiode, the receiver output went to 5V as expected, however the led that is connected to my Tx2 pin glows. Now how on earth is that possible??? This obviously means that the circuit is completed when I get a 5V output at Rx1. Which obviously concludes that Tx2 and Rx1 are interally shorted .Am I going mad, this is bizzare. I also thought that mx board might have gone bad, However after that I have tried all possible combinations of Tx and Rx pins, same result everytime. Can someone please throw some light on this??
Just so that everyone can see what I am talking about, I am attaching another image here where I had connected the LED driver with Tx1 and the comparator output to Rx3. Now I put light on one of my sensors using a cellphone flashlight and you can see the LED glowing in the picture. Can anyone give me a sane explanation for this? There is no program running on the board obviously, since it is not powered. It has to do something with the internal circuitry, does anyone here have any idea about this?
If you check the comments on the delay statements on these two links, you will see what I meant.
That delay is in there to give the ADC time to discharge between readings. It has NOTHING to do with reading Serial data, sending Serial data, or anything NOT involving the ADC. And, even then, it's use is questionable.
PaulS:
That delay is in there to give the ADC time to discharge between readings. It has NOTHING to do with reading Serial data, sending Serial data, or anything NOT involving the ADC. And, even then, it's use is questionable.
Yes I do get that, as I said I was trying anything and everything to maker this thing work. I had not put it in my code initially, anyhow I have removed it again, and yes the result is still the same as expected. You might want to take a look at my previous two replies and if possible help me with the bizzare stuff that is happening.
xenonforlife:
Just so that everyone can see what I am talking about, I am attaching another image here where I had connected the LED driver with Tx1 and the comparator output to Rx3. Now I put light on one of my sensors using a cellphone flashlight and you can see the LED glowing in the picture. Can anyone give me a sane explanation for this? There is no program running on the board obviously, since it is not powered. It has to do something with the internal circuitry, does anyone here have any idea about this?
You've created a very expensive piece of wire using the MEGA's input protection diodes, but that's not exactly useful is it?
MarkT:
You've created a very expensive piece of wire using the MEGA's input protection diodes, but that's not exactly useful is it?
Haha, no that is not useful at all, however it puzzled me why this was happening at all? This was not my objective anyways, just saw this happening by chance so got curious to know how exactly I observed something like this...
