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OpenTracker+

Discontinued Product

This product has been discontinued. Information is provided for reference only.

You can browse the OpenTracker+ source code at Freepository or retrieve it using SVN with the username and password 'guest'. The free special edition version of CodeWarrior for Microcontrollers can be used to compile the source code. The .s19 file generated by CodeWarrior can be uploaded to the tracker using otwincfg.exe.

OpenTracker+

OT1+ in Case OT1+ PCB

The OpenTracker+ is the second generation of OpenTracker that Argent Data produced. It is a single through-hole board with two DB9 ports on it, one for programming and GPS data in, and the other port for radio connection.

Features include: - 1200, 300, and PSK31 transmit of APRS protocol data. - Encode and transmit data from several supported weather stations. - Report temperature and voltage from on-board sensors. - Outputs waypoint data for display on various external devices.

The firmware is programmable via the OTWINCFG program. The unit does not print all received packets, although it does decode it for efficient channel usage.

The OpenTracker+ has a single port for computer or GPS connection. The OpenTracker2 has two ports for GPS/computer.

OpenTracker+ SMT

OT1+ SMT v1.5 Schematic OT1+ SMT v1.5 Layout

The OpenTracker+ SMT is a 28-pin board that fits into a standard IC socket. The board consists of a Freescale HC908JL16 processor and a regulator. No LEDs are included on the board. The board accepts either 5V directly to the Vcc pin, or 6-28V through the regulator. Max current draw (during transmit) is about 28 mA.

Note: The on-board regulator (78L05UA) may not be able to provide enough current to power the OT1+ SMT and a GPS.

The OTWINCFG program is used to program the board. The custom software configures 8 pins to read A/D information and report it in the telemetry APRS packet.

Analog values correspond to pins ADC1 through ADC5. The binary section of the APRS telemetry packet has its leftmost two bits set to '00'. The remaining bits report states of T1CH1 and ADC6 through ADC9.

OpenTracker+ RT

The OpenTracker+ RT is a modified OT1+ based on the MC9S08AW32 processor. It was designed for commercial AVL customers. Key differences include: - 3.3V operation - Low-power shutdown mode - Position logging for retries

Currently in limited production. Source code is not published.

OT1+ RT v1.0 Schematic OT1+ RT v1.0 Layout

Radio Port Pinouts

Pin Function
1 Audio Out
2 COR / Squelch Input
3 PTT Output
4 Counter / Transmit Now Input
5 Audio Input
6 Ground
7 Power Input
8 PTT Input
9 ADC5 Input / Power Relay

Serial Port Pinouts

Pin Function
1 No Connection
2 Data In (RS-232)
3 Data Out (RS-232)
4 Power Out
5 Ground
6 No Connection
7 1-Wire Data Bus
8 No Connection
9 No Connection

COR / Squelch Input

Active high unless ‘Invert CD’ is selected in software. Do not exceed 5V.

Counter / Transmit Now Input

Grounding this pin increments a counter (if enabled) or triggers immediate transmission. Add a pull-up resistor (4.7k–10k) if needed.

PTT Input

Active low; used for mic encoder operation.

1-Wire Data Bus

Bidirectional interface for Dallas Semiconductor devices like the TAI-8515 weather station or DS18S20 sensor.

Data Out

0–5V signal, RS-232 compatible. Some devices may require a negative voltage via level shifter.

OpenTracker+ Setup and Operation

Steps: - Build or acquire cable for radio and power - Connect tracker to computer, radio, and power - Configure with OTWINCFG (set callsign, audio level) - Disconnect computer, connect GPS or weather station

Radio connector (X1) is KPC-3 and TinyTrak3 compatible.

Use the ‘HT’ jumper for PTT on handheld radios. Omit for mobiles or incompatible HTs.

Power range: 6.7–28V DC Maximum measurable voltage: 18.5V

Power may be supplied via pin 7 (radio) or pin 4 (data), with jumper installed.

Receive Adjustment

Tracker can use carrier detect (DCD) to detect only valid data. Configure using OTWINCFG.

Transmit Adjustment

Two ranges (set via JP1 HI jumper). Tune via OTWINCFG.

If no deviation meter is available, increase audio until no louder, then back off slightly.

Proper transmit level is critical! Overdriving will make packets undecodable.

Action Meaning
Rapid green blink Channel in use
Single green flash Valid GPS fix
Double red flash Invalid GPS fix
Solid red Transmitting or in config mode
Single yellow flash Received position decoded

Firmware Revision History

Build 54896

  • March 6, 2009: Fix profile switching on ADC input, telemetry pin match to manual.