Testbed Motes

Figure 1:  Testbed Mote, fully assembled without Ultrasound Cone and Ultrasound Board.
Sensor Node Picture


The purpose for making a printed circuit board for the mica2dot motes used in the Pursuit Evasion Game (PEG) demo are:
  1. Pull out the pins so that it can easily interface with the eMote (Ethernet Programming Board) for programming and extracting data while still connecting with the battery board (must be on the bottom) and ultrasound board (must be on the top).
  2. Allow for the Telos mote to replace the mica2dot and power/interface with the mica2dot sensor boards daughter boards.
  3. Option to disconnect from a wired interface and power off the battery without reassembly.
  4. Off board, easily accessible reset switch (SW1) and off switch (U3).
Quirks that are solved by the pinOut board:
  1. The mica2dot battery board was designed such that it took an input voltage of 1.2 volts and provided 3.3 and 5 volts on the power lines.  While the specification sheet for the DC-DC step up converter on the charger board says the step up converter can accept up to Vout (in our case 3.3 Volts) on the input line, in practice feeding in 3.3 Volts  to the charger board actually causes a noisy signal on the output power lines.  This noisy signal apparently interferes with the radio, or some other circuitry, such that the packet loss rate significantly increases.  The solution was to step down the voltage on the input to the charger board using the LM317 Voltage regulator.  (I was unable to find an appropriate capacitor to clean up the power signal, so I gave up).
  2. The mica2dot somehow manages to source current through the UART_RXD0 line even when the power line is turned off.  As a result, the mote may stay on by powering off the eMote connection, even if you set the power switch to off.  The fix for this was to place a 40kOhm resistor between  the mote and the eMote's UART_RXD0, such the when the power line was turned off, the voltage and current flowing through that pin would be too low to turn on the mote.
See the MIB600 programming page for usage notes.

Hardware Files:

Warning: I did not manage to make a bug free design.  As a result, you will need to make a few simple hardware fixes (mentioned in the assembly instructions) using wire wrap, solder, and  an external component (the LM317).  If you are making the printed circuit board yourself, it would behoove you to make the appropriate fixes to avoid the unnecessary work of patching the PCB.  Contact Phoebus if you are unsure of what has to be fixed.
Board
 Schematic
 Layout
 OrCad Files
 Gerbers
 Bill Of Materials
pinOutTestTelos3 (latest version, but buggy... see above warning)
 pdf
 gif (black and white)
 DSN MAX
 zip *
 xls
* if you are making the boards, remember to change your contact info in the readme.txt file that's included in the ZIP file.

Other Assembly Accessories/Supplies
 Bill Of Materials
 Bill of Materials for Hardware Fixes (Patches)
Hardware for pinoutTestTelos3
 xls
 		xls

Assembly Instructions:

Mica2Dot Boards Assembly
PinoutTestTelos3

Archives

Testbed Mote Concept Design (ppt)