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Infrared Target Board: How to Assemble

Click Here for pdf assembly instructons.
Step by step instructions are posted below.

IR Target Schematic

If you do not have a pre-programmed ATtiny24 microprocessor, which is included in the kit, please download this hex file:
(The fuses are left in their default condition with the DIV8 fuse ON to run at 1 MHz.)
IR Target Software Hex File

The source code for this project is available here:
IR Target Software Source Code File


Included in Kit
  • 1 ATtiny24. Atmel microcontroller(pre-programmed)
  • 1 100 uF electrolytic capacitor
  • 2 1.0 uF ceramic capacitors
  • 1 red LED light
  • 1 white LED light
  • 5 1K resistors
  • 4 100 ohm resistors
  • 1 10 ohm resistor
  • 1 speaker
  • 1 battery holder
Required Tools:
  • Solder Iron
  • Small Wire Cutters
Recommended Tools:
  • Needle Nose Pliers
  • Small Vise or PCB holder with rubber pads
  • Magnified Lamp
Required Materials(Not Included in Kit):
  • Solder
Optional Materials(Dependent on your prefered target design)
  • Craft sticks for flag poles
  • Cardboard for target images
  • Cans to be knocked down
  • 3/16 inch heat shrink to attach craft sticks to servo horn

Electronic Assembly Instructions

IR Target Parts Placement

Step 1

- Socket for U1. Be careful to put the notch nearest the diodes as shown on the silkscreen. While this has no effect on the circuit, you will be less likely to insert U1 in the wrong direction later. - C1 and C2 - C3. Make sure that the long lead is soldered to the square hole marked with a plus sign (+). - U3. Inserted to match the silkscreen pattern.
Step 2

-R4, R8, R7, R11 and R15. These are the 1Kohm resistors (Brown-Black-Red). Bend the leads 90 degrees at the body and insert into the holes on the board.
Step 3

-R1, R3 and R9. The 100 ohm resistors (Brown-Black-Brown).
Step 4

-R16. The 10 ohm resistor (BrownBlack-Black)
Step 5

Q4, Q5 and Q8. Insert to match the silkscreen pattern.
The target board can be assembled to operate from the edge or from the face. The assembly will depend on how the target is to be mounted. If the target is going to be mounted flat down as when taped to the battery box then U2, D1 and D2 should face off of the edge of the board.
Step 6

-U2. Make sure the rounded dome faces away from the board as indicated by the silkscreen. -D1 and D2. Insert each LED so that its flat edge matches the silkscreen. The square pad is positive which is the long lead of the LED. Leave enough lead length to be able to bend the LEDs over the edge of the board.
Step 7

If the target will be mounted in a box with the flat side facing the shooter then U2, D1 and D2 will point away from the component side of the board
Step 8

-U2. Insert U2 with the rounded dome matching the pattern on the silkscreen. Leave about ½ inch of lead space to allow U2 to be bent 90 degrees and remain over other components on the board. After soldering the leads, bend U2 so that the rounded dome is facing away from the flat side of the board.

-D1 and D2. Insert the long lead of each LED into the square pad of the board. Leave enough lead length so that the LEDs are the same height as U2.

-P2. Solder the 3 pin header into P2.
Step 9

The included speaker can be soldered directly to the board. Bend the leads slightly in as shown to match the holes at SP1 on the Printed Circuit Board.
Step 10

Insert the speaker into the SP1 holes and solder the leads.
Step 11

If a louder sound is desired a larger speaker can be mounted externally with wires soldered to the board at the SP1 silkscreen position.
Step 12

The battery holder is soldered to P1. Make sure the black lead is soldered to the hole nearest the corner of the board. A power supply can be used instead of the battery pack if the target is going to be left on for long periods of time. The power should provide between 5 and 12 volts. Note that most servos operate at between 5 and 7 volts. If the same power supply is to be used with the servo then it should not be above 7 volts.
Step 13

If the servo is going to be powered by the same power source as the target board then a jumper can be installed between P1 and the pad between U1 and P2 as shown.
If a separate power source is used for the servo then it can be soldered in the holes next to P2 as shown. The negative lead should be in the pad nearest the edge of the board.
The electronics assembly is now complete. You can insert four AA batteries in the battery holder to test the device. When the battery switch is turned ON, the speaker will produce a sound effect. Shoot an IR gun at the target. If a ringing sound is heard or the LEDs flash then the target is functional.

Mechanical Assembly

The IR target electronics can be used to make a variety of targets such as simple flashing lights or moving flags. Use your imagination to create different personalized targets. Here are a few examples.
The easiest target to build has no enclosure at all. Just stick the electronics board and servo to the battery holder with double sided foam tape. A stick is attached to the servo and a flag is taped to the stick. When the target is shot, the flag flips down and then returns back up after a time delay.


Operation of the IR Gun is very simple. Just point an IR gun at the target and press the trigger pushbutton. The target will respond with flashing LEDs, a sound effect and a servo movement.

Note: The target electronics uses power from the battery when it is ON. The batteries should be switched OFF when the target is not in use. An external power supply can be left ON continuously for an always available target. If using batteries, remove them from the battery holder if the target is not being used for an extensive period of time to prevent damage from leaking batteries.

IR Target Parts List

Quantity Schematic
Description Picture
1 U1 ATTINY24. Atmel microcontroller.
1 C3 100 uF electrolytic Capacitor
Panasonic ECA-1EHG101
2 C1, C2 1.0 uF ceramic Capacitor
Everlight Electronics
5 R7, R8, R9, R11, R15 1K Resistor
Stackpole Electronics CF14JT1K00
3 R1, R3, R9 100 ohm Resistor
Stackpole Electronics CF14JT100R
1 R16 10 ohm Resistor
Stackpole Electronics CF14JT10R0
1 SP1 Speaker
Kobitone 254-EMB15-RO
1 P1 Battery Holder
Eagle Plastic Devices 12BH348/C-GR
1 U2 IR Receiver
Everlight IRM2638
1 Socket for U1 3M 4814-3000-CP
1 U3 Low Drop Out 5 volt regulator
ON Semiconductor LM2931AZ-5.0G
3 Q4, Q5, Q8 NPN Transistor
Fairchild 2N3904BU
1 P2 3 Pin Servo Header
Molex 90120-1086


How to Solder


How to Read Resistor Values


This work is licensed under a Creative Commons Attribution 4.0 International License