Changes from Rev 1.3:

• Increased solder pad size for button for easier soldering
• Increased solder pad size for IC1 for easier soldering
• Moved button down for more clearance and easier soldering
• Moved LED2 right for more clearance from IC1
• Altered/added text labels

This is a new updated version of the Alexander Bierbrauer’s IR transponder for multirotor (drone) racing with EasyRaceLapTimer system. This model has a button to allow changing the transponder code at the field. This minimizes transponder conflicts, especially when racing with other groups using the same ERLT system.

This board is intended to be powered by 5V from a spare servo connector on your receiver or flight controller. The hole in the board is for cable strain relief.

Note: ATTiny85 needs to be programmed with applicable code from EasyRaceLapTimer project. This board has not been tested.

Parts to populate each board:

• ATTiny85 SOP8
• MMBT2222A
• 33Ohm 1206 Resistor
• 330Ohm 1206 Resistor
• 1206 SMD LED
• 100Ohm 1206 Resistor
• SMD Tact Switch 3x6x2.5mm
• Infrared 950nm LED LD274-3 or TSUS5202
• 12mm Heat Shrink
• 30cm male to male servo extension (cut them in half for 6 inch leads)

Optional (but recommended):

• 10uF 1206 Capacitor

Required for Programming:

• SOP-8 programming clip
• USBASP or similar programmer

For more informaiton visit:

• EasyRaceLapTimer.com
• GitHub Project Page
• RCGroups.com thread
• Facebook Group

EasyRaceLapTimer Base Station Raspberry Pi Hat

Old static transponders (must be reprogrammed to change transponder ID): 5V SMD R1.2 version 5V Through hole R1.1 version Battery balance port (7-8.4V) R1.2 version