Communication modes

Below are communication modes for Explorist 400/500/600

There are 3 different modes of communication:

a) For file transfer. It appears when "File transfer" is selected from within Menu-Adv.features-Communication menu of the Explorist. When this mode is selected Removable drive (USB mass storage device) appears on PC side. Files then can be copied or moved between directories of PC and internal Explorist memory or SD card (if inserted).

 

b) USB NMEA mode. In this mode Explorist generates NMEA messages, they can be used in many third party software. When "NMEA Data comm." is selected from communication menu of the Explorist; PC side responds with appearing the modem in the list of hardware devices, USB Mass storage device disappears from the list.

This modem has an associated COM port (in my case it is COM6; which port is assigned can be found using modem properties dialog).The associated COM port can be used as virtual serial port to grab NMEA messages. This mode is similar to virtual serial port mode when USB-RS232 cable (adapter) is used with Meridian/Sportrack line but not exactly the same. In contrast to standard virtual or real serial port, serial port associated with the modem does not require any settings of baud rate, number of bits, number of stop bits or flow control. Driver does it automatically. Many programs, like Microsoft Streets&Trips, old MapSends, Hyperterminal communicate with Explorist in this mode automatically, no settings are needed. If you are going to create your own program just use CreateFile Windows API function;in contrast to standard serial port BuildCommDCB, SetCommState API functions (where baud rate and others are defined) are no longer needed.

c) True RS232 mode. This mode is not specified but is very useful. This mode was first mentioned (to my knowledge) by Rhamphorinkx (http://rhamphorinkx.newmail.ru), see his messages on 07/15/05 in mobilemapper2 yahoo group). Rhamphorinkx used this mode to upload/download maps/firmware in the hidden menu mode. He designed also some circuit (based on MAX232 chip) to connect USB connector of Explorist to RS232 (see his messages in mobilemapper2 yahoo group). Please do not be screwed up with the main content of his site (serial communication with Explorist 100/200/300), this mode is mentioned only in his messages to mobilemappe2 yahoo group (and links inside),

Below I describe in details how true RS232 mode can be used to grab NMEA messages. This mode can be used when Explorist is connected to some device which is not PC running Windows. For example, this mode can be used for PDAs, PC under Linux or Apple computes. This research was inspired by discussion in mobilemapper2 yahoo group (08/04/05).

In this mode Tx pin of USB connector is used as Tx pin of RS232, the only difference the signal must be inverted. In my experiments I used simple inverter built with using one npn transistor (different circuit can also be used, such as MAX232 based or NAND logical gates). The schematic diagram for transistor inverter (used in my experiments) is shown in Fig. 1.

Note: many PDA have inverted input for serial port. In this case inverter not needed. For example I've succsesfully connected my explorist500 to Dell Axim50v directly without any electronics.

Fig1. Tx of inverter is connected to Tx pin of Explorist's pads or to Tx pin of USB connector. Output of inverter goes to pin 2 of RS232 (male, PC side)

Now we must set Explorist to communicate in true RS232 mode.

True RS232 mode was tested on the PC computer where no any Magellan software or drivers were installed; windows hyperterminal.exe program was used to capture the output.

If we will try to set NMEA output from standard communication mode of Explorist, there will be some ASCII output, but "USB not ready" will be shown at the end and no NMEA output will be generated. Below this output is shown, ( Explorist was started and NMEA output was tried to be set using standard way from the Explorist menu).

To overcome this problem, the Explorist first must be started with "Power only" mode, and then NMEA must be set from the hidden menu mode:

Press Menu key, then press right-left-right-left arrows to enter to the hidden menu mode (see http://rhamphorinkx.newmail.ru). From "40" menu select desired baud rate, and from "41" menu set NMEA output as shown in the following figures. After these operations are finished the Explorist will return to standard mode (when map etc. are shown)

 

NMEA output appears in true RS232 mode, this mode is permanent, not necessary to set the mode again when Explorist is started (until you will need standard USB mode, in this case just set the mode as described in the manual, or in the first section of this page). All screens of the Explorist will also be shown properly; no difference between standard USB mode and true RS232 mode was found.. Here is the output (Explorist was powered on; after some start-up messages, the NMEA appears):

Do you see "APPLE start" and "NAND" at the beggining? Hope you can now guess what does it mean ;)