PNOK Messages

Introduction

The Bluetooth GPS PSY supports Nokia PNOK extensions to the NMEA 0183 standard.

The PSY polls the Bluetooth GPS device to check if it supports PNOK. If it does, PNOK messages beginning with the string $PNOK are used instead of the NMEA $PSRF messages described in NMEA messages.

The PNOK messages used for communication between the PSY and a GPS device are listed in the following sections.

Required background

Knowledge of theThe NMEA 0183 Protocol is helpful in understanding this document. Knowledge of the PNOK protocol is required.

PNOK query message

The PSY sends the message $PNOK*1A\r\n to the GPS device to query support for PNOK.

The GPS device returns an OK message if it supports PNOK.

GPS initialisation messages

The messages GPGGA, GPRMC, GPGSV, GPGSA and STAT are turned on with an update interval of one second. See NMEA message for a brief description of the meaning of the NMEA messages. The message STAT requests periodic updates.

Message : $PNOK,MSGS,1,1,1,1,,,1*21\r\n.

Power saving mode message

When the PSY initialises the GPS device, it sends the message LOWPWR to turn on GPS power saving mode.

Message: $PNOK,LOWPWR,1*2A\r\n.

Night Mode message

Night Mode sets any device display or indicators for use in dark conditions. A GPS device may darken its display when it receives a Night Mode on message.

Message for setting night mode off: $PNOK,NIGHTMODE,0*75\r\n.

Message for setting night mode on: $PNOK,NIGHTMODE,1*74\r\n.

Hardware and software version messages

The PSY sends the message VER to request Bluetooth and GPS hardware and software versions.

Message: $PNOK,VER*77\r\n.

Messages summary

This section describes the messages the PSY sends and receives from a GPS device.

Command and confirmation messages

The table below lists the command messages sent from the PSY and confirmation messages sent from the GPS device.

Event messages

The STAT message is sent from hardware to the PSY to return periodic status information.