Long range data transport

Hello guys

I read about the max distances on different data communications.

My project is about a magnetometer on an antenna tower indicating azimuth direction. More exactly a HMC5883 board. The HMC will be like 30 meter from the house, where I need to see the value. I read that the I2C prrotocol can't handle that distance. Also moving the whole arduino outside, but with that method I can't connect a small LCD display in house.

What do you reccomand?

I thought about buying 2 arduino boards, putting one of them at the tower and the other one in house and connecting them with CAT5 cable as a SERIAL connection.

Do you have any other cheaper / safer ideas?

Thanks

My first attempt would involve 30m of cable and a very slow I2C implementation, maybe a few hundred bits per second.

Why not use 433 Mhz radio to transmit serial to the lcd ?

AFIK. Ethernet should be able to easily handle 30m, and you can modify the Ethernet to also send the power if you don't already have a separate power feed

I've used RS232 (+9V/-9V) up to 75 ft. You can get up to a 100 ft with +/- 12V RS232

APC220 57600 - 9600 BAUD 1KM

I thought about buying 2 arduino boards, putting one of them at the tower and the other one in house and connecting them with CAT5 cable as a SERIAL connection.

I would use 2 Arduinos and connect them with video coax cables, using I2c or serial.

Well, you could use any of those types of wired connections, but there’s one word you should take into account… “safety”.

An antenna makes a pretty good lightning rod, and an outdoor cable can get incredibly high spikes from nearby strikes.

Use radio. Really. It’s cheap, safe, and reliable.

lar3ry: An antenna makes a pretty good lightning rod, and an outdoor cable can get incredibly high spikes from nearby strikes.

That's a very good point.