LICENSE TERMS License terms: This hardware design document package (comprised of the files listed below) is distributed under the terms of the GNU General Public License as published by the Free Software Foundation (either version 2 of the License, or at your option any later version) as it is construed in the "MIThril Hardware Design GPL Interpretation" version one or any later version. You may freely redistribute this document package and/or modify the hardware design under the terms of this license. This hardware design is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License and the MIThril Hardware Design GPL Interpretation along with this document package. If you did not receive a copy of the GPL, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. If you did not receive a copy of the MIThril Hardware Design GPL Interpretation, contact the MIThril team via email or in writing at 20 Ames Street, Building E15 Room 383, Cambridge, MA 02139. Overview The Squirt Infra-Red Beacons are designed to be a low-cost indoor location and person identification system. Each beacon broadcasts a 4-byte address and checksum using the Sony IR remote control protocol. The receiving system performs a reverse lookup on the beacon ID to determine the current room (using vertical sensor for ceiling mounted beacons) or the current patient (using horizontal sensor for name badge beacons). Each beacon includes a PIC12CE519 microcontroller, which uses 16 bytes of EEPROM to store the beacon ID and configuration data. A built-in programming header allows this data to be quickly updated. Our initial production run of 500 units brought the price of fully assembled units to just below $10. Fifty of these beacons are currently deployed around the 3rd floor of the Media Lab and provide location information for ongoing experiments. Depending on location, these Squirts are either battery powered (20-day lifetime) or line powered with a 5v wall transformer (LED lifetime). Additionally, a few Squirts are powered using solar cells hidden inside the fluorescent overhead lights. Questions and comments regarding this board design should be directed to . Release Notes Version Squirt2.x hardware notes: Three separate versions of the Squirt hardware exist: The original 2.0 design by Ari Benbasat (using PROTEL) was the basis of our 500-unit production run. The 2.1 design was created by Josh Weaver (using EagleCAD), and uses the slightly larger PIC12CE519-SM package. The Squirt21-45 variant rotates the IR LEDs by 45 degrees to allow a tighter beam "focus". The microcontroller should have been the low-power version of the same part (PIC12LCE519). Unfortunately, this component was in severe shortage at the time of production. Version Squirt2.x software bugs: The irON() function in squirt2b.c generates a slight timing offset for each of the 4 IR LED. This is not a severe bug -- the IR receiver code includes a work around. Document Package Contents Meta Information: README.txt. . . . . . . . this file GPL.txt . . . . . . . . the GPL version 2 MHDGPLI.txt . . . . . . . the MIThril Hardware Design GPL Interpretation squirt2.jpg . . . . . . . Squirt 2.1 publicity image \code . . . . . . . . . Associated software \ARI . . . . . . . . . Ari's 2.0 Crystal/Squirt design \eagle . . . . . . . . . Josh's 2.1 Crystal/Squirt design Associated Software: (found in the code directory) config.c . . . . . . . . quick and dirty program to initialize Squirt2s via serial port config . . . . . . . . compiled version of the above. squirt2b.c. . . . . . . . C source driving the embedded PIC microcontroller. 12ce519.h . . . . . . . . CCS header file required for the PIC12CE519. defs_12c.h. . . . . . . . CCS header file to access PIC12CE519 EEPROM. crystal.hex . . . . . . . compiled C code programmed onto production Squirt run. Ari's Crystal Tag/Squirt design: (found in ARI directory) BOM-ari . . . . . . . . Ari's Bill of Material squirtmask.zip . . . . . . Ari's design files used for the production run. Eagle Cad Design Files: (found in the eagle directory) Squirt21.sch . . . . . . . schematic Squirt21.brd . . . . . . . PCB Squirt21-45.sch . . . . . . schematic with LED's rotated 45 degrees Squirt21-45.brd . . . . . . PCB with LED's rotated 45 degrees Platform Independent Design Files: (found in the eagle directory) Squirt21.sch.ps . . . . . . PostScript schematic Squirt21.netlist . . . . . netlist Squirt21.pinlist . . . . . pin list Squirt21.bom . . . . . . . bill of materials (Digikey part numbers) Squirt21-45.sch.ps . . . . . PostScript schematic Squirt21-45.netlist . . . . netlist Squirt21-45.pinlist . . . . pin list Squirt21-45.bom . . . . . . bill of materials (Digikey part numbers) PCB Layer Images (encapsulated PostScript, found in the eagle directory) Squirt21.cmp.ps . . . . . . component side Squirt21.sol.ps . . . . . . solder (bottom) side Squirt21.stc.ps . . . . . . solder mask, components side Squirt21.sts.ps . . . . . . solder mask, solder side Squirt21.plc.ps . . . . . . silk screen (top) Squirt21.pls.ps . . . . . . silk screen (bottom) Squirt21-45.cmp.ps . . . . . component side Squirt21-45.sol.ps . . . . . solder (bottom) side Squirt21-45.stc.ps . . . . . solder mask, components side Squirt21-45.sts.ps . . . . . solder mask, solder side Squirt21-45.plc.ps . . . . . silk screen (top) Squirt21-45.pls.ps . . . . . silk screen (bottom) Gerber Files: (found in the eagle directory) Squirt21.cmp . . . . . . . component side Squirt21.sol . . . . . . . solder (bottom) side Squirt21.stc . . . . . . . solder mask, components side Squirt21.sts . . . . . . . solder mask, solder side Squirt21.plc . . . . . . . silk screen (top) Squirt21.pls . . . . . . . silk screen (bottom) Squirt21.whl . . . . . . . aperture file Squirt21-45.cmp . . . . . . component side Squirt21-45.sol . . . . . . solder (bottom) side Squirt21-45.stc . . . . . . solder mask, components side Squirt21-45.sts . . . . . . solder mask, solder side Squirt21-45.plc . . . . . . silk screen (top) Squirt21-45.pls . . . . . . silk screen (bottom) Squirt21-45.whl . . . . . . aperture file