Alberto Tam Yong

Technology and Projects

Salvation Army - Robot

Pasadena Salvation Army PAL Program Robot for Fall 2014


Currently, the robot board is on version 003.


GitHub Files:

  • EAGLE schematics and board files
  • Board DXF (without traces)
  • Board PNG (for reference)
  • Schematic PDF
  • Gerber board files
  • Arduino code for bluetooth control
  • BOM for electronic board and motors
  • BOM PDF (short version without links)

Robot Board v001


The board features an ATmega328p microcontroller with the Arduino UNO bootloader to allow for reprogramming using an FTDI board. An ICSP, 2x3, connector also allows for the microcontroller to be programmed using Atmel AVR Studio or for burning a new bootloader. All the I/O pins have been made available to connect using either female headers or male headers. The image below shows the board populated with male headers. The pins A0 to A5 have also been connected to a 3-pin header setup that includes a connection to GND and 5V to be used with hobby servo motors, such as the ones used in RC cars and airplanes.


For power, the board includes a 7805 linear voltage regulator and a screw terminal connector for easy installation of a battery. The input voltage for the board should be between 7V and 35V. All the same, it's not recommended to use any inputs much higher than 12V since it would require for the voltage regulator to dissipate more heat depending on current.


An SN754410 motor driver, a drop-in replacement for an L293, allows the board to drive up to two motors at 1A. Diodes were included for back-EMF protection since the SN754410 does not include them. Motor leads can be easily mounted using screw terminal connectors.

Improvements include a smaller board, added capacitors to increase stability, symmetrical screw holes, and 3.5MM terminal blocks instead of 5MM.

(Robot Board v001 - Populated)

(Robot Board v001 - Schematic diagram)

Robot Board v003

(Board PNG - for reference)