hello_radio_016
hello_radio_016 assembled by Shelby Doyle
Board fabrication by milling
This board requires a ground plane underneath the circuitry to define
the impedance of the microstripline traces coming out of the MRF49XA. The preferred route is to mill the board out of a double-sided PCB
blank. Alternatively, the top traces could be milled from a single-sided PCB blank with a strip of adhesive copper foil on the back
to define the ground plane. In either case, at least one connection should be made between the top and bottom ground planes, preferably at
the left edge of the board.
For the top traces, use an 1/64" end mill with a diameter setting of 0.38
mm to ensure the toolpath is generated for all cutouts and isolations
$ png_path hello_radio_016-top.png hello-radio_016-top.path 1 0.38 4 0.5 0.5 # in out error diameter contours offset-overlap intensity
hello_radio_016-top.png @ 2400 dpi
For
the via drils and board cutout, use a 1/32" end mill with a diameter setting of 0.79 mm
$ png_path hello_radio_016-top.png hello-radio_016-top.path 1 0.79 4 0.5 0.5 # in out error diameter contours offset-overlap intensity
hello_radio_016-cutout.png @ 2400 dpi
Board artwork for milling
hello_radio_016-top.png (Top layer image)
hello_radio_016-cutout.png (Cutout image)
Schematics, board layout, assembly diagram, BOM
hello_radio_016-sch.pdf (Schematic)
hello_radio_016-brd.pdf (Board layout)
hello_radio_016-assembly.pdf (Assembly diagram)
hello_radio_016-bom.txt (Bill of Materials)
Object code, source code, boot loader, makefile
hello_radio_8MHz.hex
hello_radio_20MHz.hex
hello_radio.c
hal_hello_radio-016.h
ATmegaBOOT_168_pro_8MHz.hex
makefile
Eagle design files
hello_radio_016.sch
hello_radio_016.brd
hello_radio_016.lbr
Antenna options
Instead of an SMA connector and antenna, a length of wire can be
soldered directly to the center pad of the SMA connector
footprint. The wavelength of an 868 MHz carrier is about 34.5 cm,
so use at least 1/4 of this wavelength (8.6 cm).
Serial interface and protocol
[to be added]
Fuse settings
avrdude -U lfuse:w:0xf6:m -U hfuse:w:0xdd:m -U efuse:w:0x01:m -U flash:w:hello_radio_20MHz.hex -p m168 -P /dev/ttyACM0 -c stk500v2
Brian Mayton, David Cranor, Rehmi Post