The module consists of:
The PCB hosts very few components and soldering them is a rather straightforward operation. For use with motors, you would normally use the connectors M1-M10. To save space inside the case, it's recommended to use right-angle PCB connectors and to soldier them with a slight upward angle. This can easily be accomplished by fitting a small fold of paper underneath the headers to hold them in place while we soldier on the back. See the photo below.
Components need to be soldered from the most shallow (closer to the board) to the deepest ones (away from the board). After the connectors, we soldier the Darlington arrays. Notice the orientation. IC1 and IC2 need to be soldiers with the pin notch down; IC3 wants the pin notch up. After the array, you will want to soldier the 3-way header for the jumper J1.
<aside> ⚠️ Note the orientation of the Darlington arrays! It is very important that they are soldiered in the right orientation!! The two on the left have the notch pointing down, while the one on the right has the notch pointing up.
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The final board should look similar to the one below. The Arduino micro can be soldered directly to the board through its header pins or a socket could in principle be installed on the PCB for easy removal. A socket too high may not fit in the case though. To save room inside the case, we prefer to solder the Arduino directly to the board but before you do that, make sure everything is working as there is no easy way back from that.
<aside> ⚠️ Double-check the orientation of the arrays and of the Arduino before you solder them.
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