OpenTracker1+ SMT

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OpenTracker1+ SMT
OpenTracker1+ SMT Schematic

Assembled and tested OpenTracker+ surface-mount (SMT) board. This version of the OT1+ is perfect for installation inside a radio or any other application where size and weight are a concern. Without pins installed, the board measures 1.22 x 0.72 x 0.2" (31 x 18 x 5 mm).

All off-board connections are through a double row of holes, in a standard 24-pin DIP footprint. Two pin header strips are provided (not installed) to allow the board to be mated with another PCB or installed in a solderless breadboard.

This board does not include a built-in temperature sensor or LEDs.


Pin - Name - Function

  1. 5VIN Regulated 5-volt input
  2. RXD RS-232 data in (from GPS or computer)
  3. 1WIRE Dallas 1-wire bus for external sensors
  4. AOUT Audio out to radio
  5. ADC5 Analog input
  6. T1CH1 Timer channel
  7. ADC6 Analog input
  8. RST Reset (active low)
  9. ADC7 Analog input
  10. IRQ Transmit-now, profile select, or counter
  11. ADC8 Analog input
  12. ADC9 Analog input
  13. AIN Audio input from radio
  14. ADC4 Analog input
  15. ADC3 Analog input
  16. TXD RS-232 data out
  17. RED Red LED output
  18. GREEN Green LED output
  19. ADC2 Analog input
  20. ADC1 Analog input
  21. PTT Push-to-talk signal to radio
  22. REGOUT Regulator output - 5 volts
  23. GND Ground
  24. REGIN Regulator input - 6.5 to 28 volts

There is no on-board connection between the regulator output and the 5 volt supply. This allows the regulator section to be bypassed if an external 5 volt source is available. To use the regulator, either connect the REGOUT and 5VIN pins externally or place a small blob of solder on the two jumper pads on the bottom of the PCB.

When the telemetry option is enabled, the device will transmit an APRS telemetry packet containing 8-bit analog values for inputs ADC1-5 and digital values for inputs T1CH1 and ADC6-9