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I am looking specifically to connect to a CDMA carrier from an Arduino. In doing research, I came across a CDMA shield option (requires getting a CDMA module that you drop into a shield), but that ends up being quite expensive - the CDMA module alone is $140, as opposed to a GSM shield which runs $30-$60. I've also tried looking for other CDMA modules, but haven't been able to find much.

Even if it's not sold as a proper Arduino shield, does anyone know of a CDMA module for hobby projects?

James Kingsbery
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4 Answers4

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There are no CDMA (more correctly known as CDMA2000) modules for hobby projects. There are a lot of reasons for this, which I won't get into, but suffice it to say, it is the way it is.

EDIT

Okay, I'll bite (just a little).

  • I think the most important reason is CDMA is actually kind of USA-centric technology. While there are now a few other countries that have CDMA networks deployed, it pales in comparison to the number GSM networks globally.
  • So in the cellular services world there is a service offering called machine to machine (M2M). What this is is a service to allow various machines (think parking meters, vending machines, ATMs, etc.) to have a data connection for control and status messages. These services are usually bought in bulk at rates much lower than equivalent consumer services would cost.
  • The rest from here on out is just economies of scale. If I am making an ATM machine, would I rather be limited to a handful of countries, or be able to sell in almost all countries. The obvious choice is the latter, so these manufacturers use GSM.
  • The reason a hobbyist can get anything cheap is because some other industry is using a lot of them. For example accelerometers used to be crazy expensive, that was until millions of cell phones started shipping with them every year, and now you can get them for pretty cheap. GSM modules are relatively cheap because there are lot of devices being made with them for the above mentioned reasons. CDMA modules are not so cheap because there are not a lot of devices using them.
Jake C
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I assume when you state "CDMA" it is Carrier Detect Multiple Access. There are several that are not very expensive and can go thousands of feet such as a RS485 network. The premium would be CAN, it will give your CSMA-NDA (Carrier Detect, Multiple Access, Non Destructive Arbitration). A non-destructive bit-wise arbitration is used to control access to the bus. There are many more but these seem to be very popular. Of course you can always go to an Ethernet Network, that is not that expensive and is typically a star network where the others are point to point. This is not a complete answer but it should get you going down the correct path. CAN will not run with one node, it needs a remote node to acknowledge the transmission. Try this link for a better description: "http://bitstream24.com/controller-area-network-can-bus-arbitration-principle/' Check the people that support this forearm, they sell the modules with instructions and of course eBay. Good Luck, Gil

Gil
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  • The OP was referring to CDMA2000, as in the cellular communication, not CDMA the channel access method (which is used by CDMA2000). – Jake C Jan 28 '16 at 21:03
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Take a look at this link, you should get the impression that CDMA envelopes a lot more then Cell Phones. http://www.slideshare.net/mnsh01987/bluetooth-technology?next_slideshow=1

Since you did not state CDMA2000 and I was involved in the automotive industry I took that approach because you can use CAN, RS485 and many other adapters to implement it with the Arduino, to my knowledge a complete CDMA2000 package is not yet available to the Arduino users. Initially we tested the CDMA theory with open collector transistors on a wire transmission line then we tested CSMANDA with the same hardware. From that point custom chips were designed and implemented. This was in the early 90's.

Gil
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I am looking at NimbeLink's Arduino baseboard which works with a CDMA modem. Never tried it, but thinking of ordering one. http://nimbelink.com/skywire-arduino-cellular-shield/. Not sure if you'd put this as 'affordable' since it is $40 for baseplate + $130 for modem.

Also this Arduino WCDMA 3G. http://linksprite.com/wiki/index.php5?title=3G_%2B_GPS_Shield_for_Arduino

Frustrating to have all this cheap awesome GSM technology, but only CDMA network in my region.

Kenn
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