Anlog transmission over long distance

Hello,

I have an arduino wired up on my basement. Now I want to install LDR sensors over my house (1st floor or second floor). What is the best way to achieve this (transmit analog signal over long distance). Arduino only needs to read the LDR values once every 10 minutes or so (to update a webpage) so I'm thinking this might be an easy think to do.

For what I searched so far I think the best way would use an ADC and trasnmit the now digital signal, and using an DAC to recover the analog signal so I could read it. So far I haven't found an IC that does so (an IC that, besides doing these conversions, they would also allow the digital signal to travel meybe 200 meters of cable).

Many thanks!

Why convert the digital signal back to analog? What sort of analog display would you use to read the analog value?

You could use, for example, a 2x16 LCD display with each column displaying the level of one LDR.

Pete

I only want to read the sensor value and send it two my computer. The result is shown on my website. Do you think I don't need a driver at all to do this? Sending the value will be enough?

For Now I have this conditions: - Read analog sensor placed approximatelly 200 meters from microcontroller. - Read it's value every 5-10 minutes. - If using a driver to extend the distance, I can wait a 1 second maximum between activating the driver and actually reading it's value.

Thanks!

Presumably you want your computer to either display the number, or add the value to a graph. Either way, you don't need a DAC - the number itself is sufficient.

Pete

You You think there will be no problem reading a analog value like that? Thanks :D

Read the analog value (local ADCs) and use RS485 to send it long distances. So perhaps a promini for its ADC, and a MAX485 chip for the data transmission, with a central arduino to talk with the various prominis and interface with the PC.