This is the schematic for Micromouse at UCI's PCB. The parts are listed below the image, with the labels in parentheses. Below the labels are further explanations of each circuit so that you can get an understanding of how each circuit works and why we included them in the PCB

• SN754410NE (U2) - Motor driver, used to control the speed and direction of the two motors.
• Teensy 3.2 (U1)- Processor, will run code.
• IR Emitters (D0-D3) - Send an IR signal, which will bounce off walls, allowing for the reciever to read. Each is connected to a digital pin on the Teensy, allowing them to individual turn on and off.
• IR Reciever (Q0-Q3) - Reads how strong the IR signal is, depending on the value it reads it is able to detect if there is a wall, and how may cells away it is.
• Pololu 3081 (U5, U4) - Motor encoders, used to keep track of wheel rotations.
• LM1085 (3A) (U3) - Voltage regulator, a LDO regulator that gives a 5V source from the LiPo. 3A version.
• Switch (SW1) - Any mechanical keyboard switch
• Buzzer (BZ1) - ~5mm buzzer pin spacing, the small ones in the link fit.
• LEDs (D4, D5) - Any 3528 sized led rated for at least 3.3v
• Voltage Regulator (Linear) - Used to step voltage down
• 1.8KΩ (R1, R2, R3, R4) - Current limiting resistors for Receivers.
• 35Ω (R5, R6, R7, R8) - Current limiting resistor for Recievers.
• 47kΩ (R13, R14, R15, R16) - Pull Up resistor for switch. Value based on the LED bought. Calculate
• 1kΩ (R9, R10, R11, R12) - Resistors for MOSFET gate

In order to run your scripts on your computer, you will need to install Arduino.

• Download Arduino Software - Download the correct version based on the system you are using. Avoid downloading the Zip file if you are using Windows.
• Download Teensyduino - Download the Teensyduino software for your system. Make sure that you select the Teensyduino, as there are many links on this website that point to the Arduino website that you had downloaded the Arduino software from.

The components must be soldered in order to maintain a solid electrical connection between two circuit elements. For ease, it's recommended that you follow the order listed below of components to solder. This will help prevent a mess or short circuits.

Capacitors

IR Emitters and Receivers


On the schematic, the IR Emitters are labeled as D0, D1, D2, and D3. Find the corresponding labels on the PCB. They should be at the front of the board
Place the shorter end of the emitter in the positive throughole of the corresponding pad and the longer end through the negative side. For reference, the D0 pad is shown below.

After inserting the emitter all the way, bend the emitter's leads so that the emitter lines up parallel to the PCB AND it is centered on the emitter sillhouette on the PCB. You can now solder the emitter.
Repeat the same process for the IR Receivers. The receivers are located right next to the emitters, and are labelled as Q0, Q1, Q2, and Q3. For the receivers, the short end is also the positive end
When you're soldering the components, make sure that the LEDs line up with the sillhouettes as much as possible. In other words, the length of the leads above the PCB should be as short as possible. This will ensure that one receiver from one set will not have interference from an emitter of another set.

Motors and Encoders

The image above shows all the components you will need to install your motor to your PCB.
The first step is to attach the JST connector (the wires) to the encoder. The encoder is the mini black circuit board with a connecter pin for the JST.

To solder the encoder to the motor, use the image below as a reference. Make sure the encoder is perfectly parallel to the back end of the motor; if the encoder is crooked, it may cause some additional problems. Cover those holes on the encoder with solder while also making sure that the motor pins are touching the solder. This way, the motor pins are electrically connected to the encoders through solder. Give a slight tug to the encoder to make sure that it is firmly attached to the motor and is not loose. If it is loose, re-solder the encoder until it fits perfectly.

Finally, attach the magnet to the motor by inserting it through the mini shaft. The final product should look like the image below.

When it comes time to install the motor onto the PCB, you will need to make sure to have your motor offsets ready. First, place the motor offset onto the PCB, lining up with the motor holes.

MOSFETs and Resistors



To solder the resistor, first make sure that the right resistor value is selected. Choosing the incorrect resistor value may result in irregular functionality; to determine which resistor must be used, first look at the KiCAD schematic of the mouse. Each resistor on the PCB is labeled as "R#" (i.e. R7). Find the corresponding resistor value on the schematic, and that will be the resistor value needed at that point (i.e. R7 is labeled as 35 ohms, so you will need a 35 ohm resistor at R7). To solder, simply bend the resistor and insert them into the holes specified (as shown above). The ceramic part of the resistor should be lined up with the rectangular engraving on the PCB and should touch the PCB. Solder the ends of the resistor at the bottom of the PCB, and then cut off the ends. The final product should look like this:



The MOSFETs will be soldered on in a similar manner. All the MOSFET pads will be labeled as "T#" (i.e. T2) on the board. Place the MOSFET on the pad, with the flat face lined up with the straight edge of the MOSFET sillhouette. This will ensure the correct orientation of the transistor. Push the MOSFET in as much as you can. Solder the leads from the bottom of the board and cut off the ends.

Voltage Regulator



YouTube Video (https://youtu.be/L_DIpklxXcI).

Switches and Buzzer

Header Pins & Dip Socket
The header pins and dip socket are used for easy replacement of the Teensy and motor driver respectively in the event that they burn out.
For the Teensy, you will need two 1x14 headers and one 1x5 header. Solder them on individually in the location shown below

Header Pins for Teensy
To add connections to the Teensy, male header pins must be installed onto the Teensy. Open the pack of male header pins, and break off two pieces of 14-unit pins (since the Teensy has 14 pins lengthwise) and one 5-unit piece (widthwise). When soldering the pins on, ensure that the black caps go UNDER the Teensy board, and not on top (image shown below). Once you solder them, cut off the top leads. You will also need to insert 1 pin into the final hole in the Teensy. You should now be able to place the Teensy on the header pins.

IR Sensors

Motors

• Interrupts are needed to keep track of the wheels revolution. When the wheels position changes, the motor encoder will send a signal to the Teensy. A total of 12 signals will be sent per 1 revolution. Interrupts allow it so the Teensy can update values as soon as the encoder sends the signal (asynchronously). If the encoders were updated in the main loop theres a good chance for some signals to be missed, causing the revolution count to be inaccurate.

• To add an interrupt run the attatchInterrupt function in setup. Syntax is attatchInterrupt(pin, func, mode). The second parameter specifies the function that gets executed when the interrupt is triggered. In our case we want to put in a function that will add to the count of an encoder variable. The third parameter specifies what will trigger the interrupt. For example "CHANGE" will make the interrupt trigger whenever the pin changes value, however, "FALLING" will make the interrupt trigger only when the pin goes from HIGH to LOW. Read link for more info.

• tickCount - Two variables, one for each motor. When interrupt its triggered, increment the tick count by 1.
• emitterState - One for each emitter. Stores the current state of the emitter

• readReciever() - One method for each reciever. Returns the value read by reciever
• setEmitterState(x) - One method for each emitter. Set the state of the emitter to on or off.
• getSwitchState() - Return the value of the switch
• runMotorTime(m, speed, sec) - Set specific motor at speed for given amount of seconds. Uses delay function to count time.
• runMotorRev(m, speed, rev) - Runs a specific motor at speed for given amount of revolutions. Uses the encoder varible to count revolutions.
• setLED(l, brightness) - Sets a specific led to a certian brightness.
• setBuzzer(strength) - Sets the buzzer to a given strength.

• turnRight() - Use encoders and tickCounts of both motors to make a percise right turn
• turnLeft() - similar to turnRight()
• goForward() - Use encoders to go straight.
• turnAround() - turnRight * 2