Hello guys, I need the hardware and firmware and FCC certification for something like what is in a keyfob, with a matching receiver. No case, but the board design needs to be coordinated with the case designer. System: Two "senders" of switch states (two switches each), one "receiver. Ten meters range is enough. High transmission safety (probably needs to be a transceiver with a protocol feedback, that's why the "sender" and "receiver" above are in quotes); with that I mean that a switch change needs to arrive at the receiver with a high probability (few false negatives), and that nearby other devices (same type, or completely different) don't cause false positives. This probably means that the "senders" need to somehow be paired with the "receiver". The "senders" are battery operated; a bonus is if they can signal the upcoming end of life of the battery. Transmission latency (switch state change to output change at the receiver) under 50ms. I'm calculating with averages of 1 state change per 5s, for 5 hours per day. The "sender" is basically like a keyfob that transmits state changes of two switch inputs. Long battery life (months). Should be small (see below). The "receiver" is powered by an automotive supply and needs only run when ignition is on, so current consumption is not an issue here. If the "sender" is a transceiver, this one is also one, and would also need FCC certification. It reflects the input switch changes on four simple digital outputs. The reason I'm asking for this is that I've looked at the MaxStream ZigBee modules . It seems they would work for our needs, and they are already FCC certified. However, smaller modules would be nice. Also the (peak) current consumption precludes small batteries; they seem to need something like a CR123A, and smaller would be nice here, too. OTOH, the range is way over what we need, so it seems that a custom design could get us much closer to what we want (smaller overall size of battery plus "sender" electronics). We can't spend too much on this, but maybe if someone has already done similar RF designs and knows what needs to be done to get it certified, we can get to an agreement. Alternatively (if the above should prove to be too expensive), I might be interested in even contracting the development of the devices based on the MaxStream modules (or similar other ones). Most of the work is probably about getting familiar with the modules, so someone who already is familiar with them and has already developed a similar application probably can do this much faster than I could. Only fixed price contracts. Prototype delivery for acceptance tests to USA or Brazil; otherwise location is not a big deal. PIC firmware preferred in Hi-Tech PICC(18). Please contact me off-list if you're interested. Thanks, Gerhard -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist