This page contains information about digital and analog IO pin usage on Vorpal Mimsy 1.1. This is primarily useful if you are Arduino knowledgeable and wish to modify or expand Mimsy, for example by moving, changing, or adding new devices.

The preloaded software defines all pins at the start of the program making it easy to add or change IO pin usage. However, there are certain restrictions, noted below.

Digital Pins Edit

Digital Pin Device Notes
0 Bluetooth TX To upload your own programs using USB, you need to cut power to the bluetooth module by using the switch on the bluetooth module cable. The lights of the module will go out.
1 Bluetooth RCV See note on digital pin 0.
2 Sound Sensor The sound sensor uses Arduino Interupts and so it must be on either pin 2 or pin 3.
3 Green (+) button Only ground and signal are used, software uses INPUT_PULLUP mode
4 Red (-) button Only ground and signal are used, software uses INPUT_PULLUP mode
5 Left Motor Continuous rotation servo
6 Right Motor Continuous rotation servo
7 Ultrasonic rangefinder The rangefinder is an HC06
8 Available
9 Grip Arm motor 180 degree SG9 mini servo
10 Grip claw motor 180 degree SG9 mini servo
11 passive speaker Piezo buzzer
12 Available
13 Available

Analog Pins Edit

Analog Pin Device Notes
A0 Available
A1 Line Sensor This is a light sensor plus illuminating LED mounted to the bottom of the robot for sensing lines or light/dark areas of the floor.
A2 Available
A3 Battery A voltage divider coming from the battery power source divides the 9 volt nominal power supply into a range safe for the analog pin. This analog value divided by 102.4 gives the battery level in volts.
A4 IIC The Arduino Nano uses A4 and A5 for IIC communications. Vorpal Mimsy uses IIC for the LCD display.
A5 IIC See note on A4.
A6 Ambient Light Sensor This is a light sensor mounted to the top of the robot facing the ceiling and can be used to read ambient light.
A7 Available

Funduino IO Expansion Shield Ports Edit

In addition, the Funduino IO Expansion Shield used by Mimsy has some pins that are used. The AREF set of pins is used by Mimsy to feed the output from a UBEC to provide up to 3 amps of power for servo motors. The signal pin is not used, only the VCC and ground.

IIC for the LCD display is also connected to the Funduino IIC pins via a 4 pin connector. This leaves A4 and A5 apparently empty, but beware, those pins are in use due to IIC being drawn from the IIC connection header.

Other Arduino Resources Used Edit

TIMER1 is used by the tone() command which drives the passive buzzer. This means that PWM on pins 10 and 11 is not available if the buzzer is used.

The sound sensor uses INTERUPT1 which is on pin 2. Moving the sound sensor to another pin will therefore fail to work with the preloaded program (without other changes). So if you need the sound sensor for your modified project, leave it on digital pin 2.