LDR as a sensor

hey guyz…

I am a new bee in the field of arduino. I am doing a simple project where I am using Light-Dependent Resistor (LDR), arduino uno R3 and a BLE Shield by red bear. I want to send the LDR data (the data which shows on the serial monitor screen when we connect LDR to arduino which calculate approx value of light surrounding LDR) to my iphone via bluetooth…

Is this possible to send the data…?? LDR is not a sensor, so can we use as a sensor type…like other sensors such as LM35 temperature sensor…??

any suggestion on this will be great…
P.S. - forgive me if it is a stupid question…

Well first I’d say an LDR is a sensor (it’s certainly not an actuator), but I take your point that it’s not like a LM35 which outputs a voltage- an LM35 can’t work unless it’s hooked up to power, while an LDR always has some resistance or other.

But if you hook an LDR up in a voltage divider, then it does deliver a voltage: the junction between the LDR and the “other” resistor shows a voltage exactly like an LM35 does.

Have a look at this: Using a Photocell | Photocells | Adafruit Learning System

Edit: In fact if you draw a mental box round the LDR and the other resistor as attached, then it’s exactly like an LM35: power across Vin and GND, and Vout on the other wire.

ldr as a sensor.png

ok I got this..
but my question is can I use it with my REDBEAR BLEShield?
SInce I want to send the data to my iphone via bluetooth..

Do you have any code or example to connect it with bluetooth and send the data to my phone..?

look at this example.....I also want the same but this is in android and I am not familier with python or pyserial...

take a look...

dushyant:
but my question is can I use it with my REDBEAR BLEShield?

No idea.

LDR is not a sensor, so can we use as a sensor type..like other sensors such as LM35 temperature sensor..??

But if you know how to do it with an LM35- and I got the feeling you do- and you accept that an LDR in a voltage divider is exactly like an LM35, then you shoud be able to do the same.

thanks for reply and thanks for your support… :wink:

You kind of fooled us into thinking you were asking about using an “LDR as sensor” as that is your topic title, and you spend a lot of time talking about it. BTW, an LDR -is- a sensor. It sounds like you have that part figured out.

Anyway… I’d suggest reposting in “Programming Questions” or “Networking, Protocols, and Devices” with a subject line like “Redbear BLEshield to my iPhone”.

polymorph:
Anyway... I'd suggest reposting in "Programming Questions" or "Networking, Protocols, and Devices" with a subject line like "Redbear BLEshield to my iPhone".

Seconded....