WREN - Utah-WiESEL/wren_wsn GitHub Wiki

PCBs

You can either populate the PCBs yourself or through a fab house.

Note: when soldering the Hirose connector onto the board, make sure you are not using too much solder as it will sip into the connector and render it useless.

Case

We used Polycase as the case manufacturer. They made the following two modifications to one of their standard cases for our purposes: drilled a light pipe hole and a cut out for the Hirose connector. The model for the case is included in the repo.

The following steps are how we prepared the case. The following tasks (Step 2-5) can be done in parallel by different groups to maximize efficiency. Steps 5 and 6 are best done one after another.

Step 1:

Gather the following items:

  1. Light pipes (Digikey Item # )

  2. Super Glue

  3. Double-sided tape

  4. Clips

  5. Epoxy

Step 2:

Glue the light pipes with Super glue.

Step 3:

Tape the battery onto the case with double-sided tapes. See the Battery section below.

Step 4:

Tag it with the RFID tag. Notice RFID location is crucial since the tag might be useless if placed elsewhere.

Note: RFID is used for inventory purpose.

Step 5:

Put on the clips.

Step 6:

Glue the clips shut with epoxy.

Note: This step is only necessary for kids since they tend to break things.

Battery

We used small LiPO sacks, shipped directly from China.

Part Number: PL502025

Assembly

The base stations and the WREN can be built simultaneously, although to test the WREN, the base stations need to be done before hand to minimize delays.

Step 1:

Plug the battery into the motes.

Step 2:

Plug the WRENs into the base station for charging (just couple of minutes is efficient).

Note: Because our design for the gang programmer did not include a power source to power up the WRENs, you can proceed to the next step if the battery is pre-charged.

Step 3:

Program the pre-charged unit with BSL & Test Program.