Shepard Test Stand

h1. Assembly v1.0

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h3. Mechanical System

h3. Data Acquisition (DAQ) System

The assembly of the DAQ system consists of three main sub-assemblies:

# MAX31855 Thermocouple Amplifier Breakout Board

# Force Sensing Resistor (FSR) cable system

# Arduino ProtoShield

h4. MAX31855 Thermocouple Amplifier Breakout Board

* The only assembly required for the MAX31855 breakout board is to solder the header pins and terminal block onto the board. Once this is done the breakout board can be soldered to the Arduino Protoshield.

h4. Force Sensing Resistor (FSR) cable system

* The FSR came with male pins, which complicated assembly somewhat. It would be simpler to buy the version of the FSR with a female connector and make your cable fit that configuration. As it was, female D-SUB connectors that were on hand were used to connect the FSR to the CAT 5e cable that was used between the FSR and the ProtoShield. The pins were crimped on to two of the leads of the CAT 5e cable so that the female ends could receive the male pins of the FSR. The reason crimping was used instead of soldering for the pins is that it's very easy to melt the FSR's substrate, thus making the FSR useless, or at least severely altering its operation.

h4. Arduino ProtoShield

Components were soldered onto the ProtoShield in the configuration shown in the images below. Note that in the bottom view, the ProtoShield has been flipped vertically towards the bottom of the picture. This allows you to orient yourself so that you can follow the traces. For higher resolution images to aid in assembly, check the Shepard_v1.0_DAQ_Assembly_Images.zip file "here":https://opendesignengine.net/dmsf/shepard-ts?folder_id=24

*Figure 1 - Top View of the ProtoShield*

!ProtoShield_Top_View_Assembly_Edited.png!

# The MAX 31855 breakout board has the correct header pin spacing to fit the holes on the ProtoShield, so it was inserted directly. Note that the capacitor that is included with the K type thermocouple when purchased is being used. The thermocouple's reading had too much noise in it otherwise.

# The red and green wires used were "breadboard prototyping jumpers":http://www.radioshack.com/product/index.jsp?productId=2103801 from Radio Shack. Left over Ethernet cable wires can be used as well.

# The resistor was soldered directly to the ProtoShield, but care should be taken that the leads of the resistor do not short any of the connections on the board.

# A 14 pin DIP socket was used for the TLV2374 for multiple reasons including prevention of overheating of the IC during soldering, and ease of replacement in the event of damage due to a wiring mistake.

# A smaller screw terminal block for the FSR leads (left side) would have ideal, but the larger block pictured was all that was available at the time of assembly. The pins are spaced more widely on the block and thus the positioning was dictated by the spacing of the holes on the ProtoShield.

# Notice that even though the two green jumper wires disappear under the MAX 31855 breakout board in the image, they have been labeled with what pins they go from/to.

*Figure 2 - Bottom View of the ProtoShield*

!DAQ_Shield_Bottom_View.JPG!