rfPIC12F675

Anyone had experience with these PICs with on chip RF transmitters? Likes/dislikes? Are they to work with if you have previous PIC experience?

http://www.microchip.com/ParamChartSear … &pageId=76

I have an “rfPICKIT”, which includes two transmitter modules with the rfPIC12F675’s on them.

If you’re going to build something yourself, be aware that they only come in a smallish SMT package I think.

Using a ready-built module (like the rfPICKIT modules) gives you a correct PC layout (which is important), and you don’t have to track down the little L’s and C’s that are needed.

The chips are exactly like a PIC12F675, but with several extra pins that are for the transmitter circuit. There is no electrical connection between the MPU side and the xmtr side of the chip. So the MPU doesn’t ‘know’ that it has a xmtr next door.

I have the module connected to a larger board with a larger PIC on it, which generates serial data to be transmitted. In the xmtr’s on-board 675, I have simple code that monitors the serial data stream, and enables the xmtr when data comes, and turns off the xmtr a fraction of a second after data stops coming. So the xmtr only puts out a carrier when it needs to.

Pete

i only briefly looked over the data sheet. I dident realize that the 2 things were completely separated like that.

I was planning on using it kind of like how you are. Was gona use a large PIC and just have this handle the xmting. How do you like your setup? Would you do it this way again if you were going to redo the project? Or use just like a standard TX/RX module with out the extra pic? What kind of range do you get with this? I was looking for something that can do from my mailbox outside to inside the house (a mail indicator type project).

Oh also yea i realized its only available in SSOP package. which leads me to maybe wana stay away from it altogether as i have never done SMT work before. But ide still like to hear your input.

How do you like your setup? Would you do it this way again if you were going to redo the project? Or use just like a standard TX/RX module with out the extra pic? What kind of range do you get with this?

It works well - the stock rfPICKIT modules can talk to each from at least a half-block away - definitely more than that if you use a better antenna on the rcvr side.

I’ve done a couple of similar RF projects since, and have used the little modules that SparkFun sells for $15 a set. They work fine, too (after you understand the requirements related to DC balance and preamble, which is required for the rfPIC rcvr also).

So I think the reason for using the rfPIC would be if you want to do something custom on the RF portion (like running at a non-standard frequency), and I would buy the pre-assembled module and modify it, rather than go to the trouble of designing my own module.

For everything else, the little (and cheap) modules from SFE are fine.

Pete

sounds good. thanks for your input!