Custom Arduino keyless entry + auto window/trunk integration...

**jba3** · 02-15-2011, 02:18 PM

Originally Posted by Toni

Well, f my balls. Problems in paradise....

Did my first tests of both wireless systems enabled. The bluetooth is interfering with normal FOB operation. EE friend of mine seems to think since it's a high power device it's basically flooding the air with only it's frequency messing with the ability for the fob receiver to pick up what it's looking for. The further away I move the bluetooth device the better the fob signal but that only seems to get me so far. Major bummer! Still trying to debug this further

Ah, complete bummer! I was wondering how it would work with two devices - my head unit uses bluetooth for hands-free calls, and I don't know if it would be able to do that and control the in-car arduino at the same time.

**Tiberius** · 02-15-2011, 03:39 PM

Doesn't really surprise me, both bluetooth and the nRF24 are using the 2.4 GHz band and as far as I can tell the Nordic's do not conform to IEEE 802.
ZigBee tranceivers are based on IEEE 802.15.4 and should (in theory) co-exist a lot better with bluetooth and Wifi.

**Toni** · 02-15-2011, 03:44 PM

Originally Posted by Tiberius

Doesn't really surprise me, both bluetooth and the nRF24 are using the 2.4 GHz band and as far as I can tell the Nordic's do not conform to IEEE 802.
ZigBee tranceivers are based on IEEE 802.15.4 and should (in theory) co-exist a lot better with bluetooth and Wifi.

Well I'm not using the nRF24, just an ebay special running at 315mhz. I was also curious about my wireless router and it's 802.11g so I decided to test packet loss while the RN41 was on and saw no throughput issues (although I guess I could still be having some packet loss and not really know).

**Tiberius** · 02-15-2011, 03:59 PM

Ok thats strange then. I'd try shielding the receiver module.
I looked at the eBay pic. Where does the antenna go on this thingy?

**Toni** · 02-16-2011, 03:59 PM

Well I'm going to try another wireless receiver/fob implemented differently. hopefully that will work out!

Originally Posted by Tiberius

Ok thats strange then. I'd try shielding the receiver module.
I looked at the eBay pic. Where does the antenna go on this thingy?

It has it build it, you can see the trace grid connected to the inductor. This one looks like it's implemented with an RLC circuit. The new one I'm getting is implemented using a SAW crystal circuit. We'll see if that makes a difference. I guess I should have looked up if that will...or at least asked someone in the know but oh well.

**Toni** · 02-28-2011, 10:08 AM

Good news! The new module works like a charm. It is a little more advanced, has auto remote learning and rolling security codes. Also the fob is much nicer. I'm back in business!

**Stealthlabel** · 02-28-2011, 11:36 AM

nice!

**Toni** · 03-02-2011, 10:48 AM

Finished up the power folding mirror circuit. Has some nice features like individual left/right control and speed synchronization via pwm (allows me to adjust the speed of one mirrors open/close because for some reason one is always slower, noticed that on another person's mirrors as well). Yeah, I like to over engineer shit.