In the previous posting in this series on making a noise monitor for environmental journalists, I described the parts that make up the noise monitor. Due to the short turnaround time for this project, I had to rely upon readily available breakout boards and components. But, there was still time to design and fabricate a simple circuit board to integrate the components in an organized manner.
Figure 1. Circuit Schematic
The circuit is shown in Figures 1-2.
Figure 2. Eagle Design
And, the board can be ordered directly from Oshpark, as a shared design under the user “SetoLab” – “Internews Seto Noise v2”. $48.15 for 3 boards minimum (Figure 3). (Note: for the record, I don’t get any royalties from you purchasing these boards from Oshpark, and you’re welcome to use any fabricator you want to make the boards).
Figure 3. Circuit Board from Oshpark
Some additions I added to the board included a 2 pin connector (Sparkfun PRT-08233) for the battery, a barrel connector (Sparkfun PRT-00119) to power the monitor from a DC power supply instead of batteries, a power switch (Sparkfun COM-00102), and a 4-pin Grove connector (Epictinker ACC39145O)to neatly connect the Grove display. Also the holes in the board spaced to fit the screw posts on the Hammond 1591XXCBK case.
The complete built circuit with soldered components is shown in Figure 4. (Note there’s an error in the orientation of the 4-pin connector – It should be reversed before soldering).
Figure 4. Completed Circuit: (left) Electric Imp board removed, (right) with Electric Imp board attached to header.
Next: Part 4. Prototyping – Code
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