Read battery voltage remotely?

Projects General Guidance
1

Hi all,

I need something that will plug into an ethernet LAN port on a router, connect to a 12v battery, and let me read the battery voltage remotely. Can I do this with an Arduino? If so, what do I need to buy, and how do I do it?

Both 12v and 5v are available on site, so it can run off either, although 12v would be preferred.

Nice options would be logging the voltage every 5-10 minutes with timestamps (to the web page; data storage not necessary), and sending an email alert if voltage drops to a certain level.

Thanks in advance for any input.

2

That sounds completely feasible with an Arduino and Ethernet shield.

3

Any Arduino will do (Uno compatible / ATMega328 chip) and then you also need an ethernet shield, preferably one with a Wiznet W5100 chip. Combined the two should be less than $40. You can find lots of examples of how to serve a web page if you do a little searching.

To read your voltage you just need a couple resistors. If you have any interest in electronics you should buy an assortment pack of resistors, but if you just want to do this one project then a 10K potentiometer or seven 2200 ohm resistors would work (when combined to form a 8800 and 6600 ohm resistance). Voltage Divider for an example.

4

Chagrin:
Any Arduino will do (Uno compatible / ATMega328 chip) and then you also need an ethernet shield, preferably one with a Wiznet W5100 chip. Combined the two should be less than $40. You can find lots of examples of how to serve a web page if you do a little searching.

To read your voltage you just need a couple resistors. If you have any interest in electronics you should buy an assortment pack of resistors, but if you just want to do this one project then a 10K potentiometer or seven 2200 ohm resistors would work (when combined to form a 8800 and 6600 ohm resistance). http://fritzing.org/projects/voltage-divider/ for an example.

this would be the "arduino" version...
but if 40$ is too much, there are some cheaper alternatives that require some dirty work, and also some knowledge...
personally, id cashed 40$ for elegant solution

5

rabbit mini cores offers. minimodule ethernet loaded full libraries, many many examples for $30 or $35 USD, more compact, more powerfull mcu, and cheaper, did i write that?