RoboRally/docs/1_ASSEMBLY.md

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Robot assembly

This file contains assembly instructions for building the robots and soldering the electronics.

Here is how the finished robot will look like: finished robot

Components

The robot consists of the following components:

In addition you will need the following tools:

  • A soldering iron
  • Solder wire
  • Heat shrink tube
  • Some wires
  • Battery connectors (female)
  • Velcro tape
  • Self adhesive tape
  • Isolation tape
  • Pin headers

For the camera based position detection of the robots you will need:

  • A camera
  • A printer
  • Paper
  • Cardboard

Assembly instructions

Robot chassis

Assemble the chassis according to the instructions provided by adafruit (see here).

Soldering the electronics

####Preparing Wemos D1 mini and shields

Description Image
Solder on two rows of 8 male pin headers to the D1 mini D1 mini
Solder on two rows of 8 female pin headers to the motor shield . Motor shield Motor shield
Also solder a single row of bent pins to the motor shield. Make sure they are soldered on the right way around. Motor shield
Solder a jumper to the motor shield to connect the RTS and 3V pin. This will become important later on. Also solder the I2C bridge. Motor shield
Solder on two rows of 8 female pin headers with long pins to the battery shield Battery shield Battery shield
Cut off the tips of the long pins such that the battery shield nicely fits into the motor shield Mind the gap Cut off tips Nice fit

Connecting battery shield and motor shield for motor power supply

In the next step we connect the battery connector pins of the battery shield to the + and - pins of the motor shield. In addition we will add a connector to the motor shield where we can plug in the battery. Here is a schematic: Motor shield and battery shield sketch

Note: I added a new connector instead of using the one already on the battery shield because the plug of my battery wouldn't fit in the on on the shield

  • First, solder two wires to the + and - pins of the battery shield and isolate them with heat shrink:
Description Image
Cut two small pieces of wire (about 4 cm), remove the isolation on both ends and cover them with a bit of solder Battery Shield Wires
Solder the first wire to the + pin of the battery shield First wire soldered
Solder the second wire to the - pin Second wire soldered
Cover both wires with small pieces of heat shrink tube Heat shrink
Heat the shrink tube with a lighter I see fire
This is how the battery shield should look like with the two wires Two wires with heat shrink
  • Next, we create a connector for the female JST 2-Pin connector for plugin in the battery:
Description Image
Cut two small pieces of wire (about 3 cm), remove the isolation on both ends and cover them with a bit of solder DIY JST connector
Solder the first wire to the JST connector First wire soldered
Solder the second wire to the JST connector Second wire soldered
Cover both wires with heat shrink Heat shrink cover
Solder the wires to the motor shield, paying attention to the polarity (make sure it matches the polarity of your batteries!) Battery connector to motor shield
  • Now, stack the battery shield on top of the motor shield and solder the battery connector:
Description Image
Connect the + pin of the battery shield to the + pin of the motor shield. Be sure to isolate the connection with heat shrink. Then repeat the same for the - pins. Motor shield and battery shield connection
This is how it should look like in the end. Side view Top view

Next steps

This concludes the main steps for the robot assembly. The next step is to fix a problem with the firmware on the motor shield in order to use it via I2C. Head over to 2_MOTOR_SHIELD_FIX.md for the instructions.