Zigbee or ANT for serial cable replacement to CMOS camera?

Wireless & IoT
1

Hello everyone,

My apologies for the (potentially) stupid question, I’m mainly a software guy trying to teach myself some electronics. I was looking for a solution that would allow me to access a serial CMOS camera (namely the C328R - http://www.electronics123.com/s.nl/it.A/id.2581/.f ) wirelessly from a host computer. What I want to achieve is a wireless digital camera that consumes very little power while idle but can wake up and take pictures when asked to.

Is there any way to hook up an ANT or a Zigbee board directly to the serial port of the C328R camera and configure the system to wake up every x seconds and listen for a request from the server and if it hears anything send the JPEG capture sequence to the camera, take back the resulting file and send it wirelessly to the requesting host?

Any hints would be greatly appreciated.

Thank you,

Razvan

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Razvan Dragomirescu

Chief Technology Officer

Cayenne Graphics SRL

2

consider the $49 network camera from Airlink101, sold by Frys. Nice little color CMOS camera with the output as MPEG/MJPEG on IP, using a cat5 connection to the camera. I have two of these. They do stills and streaming and FTP on a time schedule you define.

There’s a WiFi version too. More expensive.

Maybe not what you’re trying to do though.

3

Thanks but that’s not what I was after. In this particular project, I need the camera to be in a “dormant” state for months/years before it receives the ok to start broadcasting. It needs to be extremely low power (something WiFi certainly isn’t :slight_smile: ). It also needs to be small and I don’t need all the fancy stuff like MPEG4 encoding and live streaming and stuff. I just need the device to wake up on demand, take a picture, send it over, then go back to sleep until the next time.

Best,

Razvan

4

i dont see any problem in this at all. initially i thought you were talking about live footage. If you are looking for a snap every few months or what ever then, zigbee should be fine. It has a max throughput of about 250kbps but a lot is lost in packet stuffing and handshake stuff. but a pic in jpeg should be about 60Kbytes so that shouldnt be too bad.

let me know how your project goes.

5

may I respectfully suggest that you/we distinguish between “ZigBee” and IEEE 802.15.4?

The latter is the MAC and PHY, in the chip sets, much like an ethernet where nodes talk using their MAC address without needing IP. ZigBee is one of several network layer (3) protocols that can be used with IEEE 802.15.4.

We wouldn’t call Ethernet IEEE 802.3 “IP”, by analogy. ZigBee is cute and easier to remember than '15.4, but it’s misleading.

Like IP atop 802.3, ZigBee is firmware that has an API between it and the chip hardware. Unlike Ethernet and IP, the API for using the MAC is defined by IEEE 802.15.4 so every vendor’s chip, or better, module, has a consistent API.

I strongly urge you to not use ZigBee unless you need meshing, due to its complexity. Digi and other make serial port extension firmware to sit atop the MAC layer in lieu of ZigBee and that eliminates all protocol complexity for simple star or point to point applications.

6

I think we’re going to use the Xbee modules on this, the ANT modules don’t seem to offer a simple serial-extender mode like the Xbees and we definitely don’t need anything other than point to point.

Should we go for the new Series 2 Xbee modules? Or can we stick to Series 1? The price difference is not very significant and the Series 2 seems to have a more complex API. Is there any reason to choose Series 1?

Thanks again,

Razvan

7

Use series 2 only if you plan mesh networking with ZigBee. And are prepared for its complexity. Otherwise, use series 1.

Use the PRO modules with higher power (under US FCC regulations anyway, not so in Japan, France), if you need longer range or better/more wall penetration.