SparkFun Forums 

Where electronics enthusiasts find answers.

Have a good idea for a new product for SFE or Olimex? Let us know!
By cosmicray
I'd like to suggest a product that you do not stock ... a latching relay (either bare THT, or SMD on a small proto board).

As an example, an AXICOM / TE Relay Products V23079-B1201-B301 / 3-1393788-3

5V coils (one to latch, one to unlatch), 28 mA on either coil, DPDT, contacts rated 2A@30V-DC, 4ms response time
(this is the THT version, but they make an equivalent SMD)

The voltage/current rating is well within the operating limit of any ATMega 5V cpu. There is also a 4V coil version, that should function at 3.3V

The nice part about this relay, is that once latched, it consumes no current until you decide to pulse the unlatch coil.