Post by jimkernsjr on May 16, 2016 0:54:44 GMT
Hello...I don't see much talk about it anymore, maybe with the Motino and miniwireless, it's not so relevant, but I have created something that I could not really find anywhere, and thought it may be of some good to others, so I post it here to try to give back since you all have done so much. Let me start out by saying I'm a programmer by trade, and i'm very weak on the electronics side, so please try to take it easy on me if you find some flaws...I'm still learining!
Attached is a Fritzing drawing, and the PDF of an etched circuit board. It has the atmega328p, plus the RFM69HW that can mount direct to the board , or though a header like I have done. Please note 2 problems with my design, but can be easily fixed by those of you who really know what you are doing.
1. You do need a bridge wire for the ground down near the voltage regulator(green wire).
2. The voltage monitor on A3 is not complete. It was also incorrectly hooked up before the switch, and come to find out this keeps the chip alive with the switch off! (blue wire)
3. It needs a CAP on the reset pin for the FTDI header. (I cheated and put a second header socket-see picture)
Other than the obvious, here are some details that you may not be able to determine from the circuit:
Voltage Regulator: MCP1702-3.3v
Power source: Cheap phone bank from 5 Below...Opened it up and hooked direct to battery though a self resetting fuse for safety. Left all the USB circuit to recharge it.
Sketch: It's Eric's old version. I liked the small code footprint, and it was supposedly very reliable. I just changed the data structure to work with Computourists 2.3 version of the gateway. With of course an activity LED on D8...That pin is in the corner of the chip and an easy target! I transmit Battery voltage, open count, and Signal Strength.
The sensor: Kind of crude and cheap but it works. It's just a glass reed switch and a magnet. I put my pull up resistor on this for greater flexibility in case I wanted to use this circuit board or Fritzing file for something else in future.
I know etching your own circuit board has no real advantage anymore. A ProMini with RFM69, or a MiniWireless or Moteino would be much better size wise. But I never did a circuit board, and this one was a good excuse to try it out
Mainly the point to it all is that I couldnt find ANYWHERE an Fritzing part for the RFM69 that would attach directly to a circuit board. So you can pull it from my Fritzing file – and sorry for not labeling the pins! I had done it, but they were all wrong – forgot about the mirror image/upside down thing!
Attached Picture, Fritzing, and PDF. Some of the points I mention should be addressed in the Fritzing, and re-exported, but I attached my export copy anyway if anyone wants to see if it's worth messing with. Hope someone else puts it to good use!
Attachments:
mailbox atmega r3b-jim.fzz (48.07 KB)
mailbox atmega r3b-jim_etch_copper_bottom-txt.pdf (14.78 KB)
