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Modem-M64🔗

The Modem-M64 is retired and no longer available for sale.

Description🔗

The Modem M64 is a two-way half-duplex 64bps acoustic modem with a robust and user configurable data link.

The M64 sets a new market standard with its record-breaking physical size, low power requirement and cost. All this combined with a very useful technical specification, the M64 opens new possibilities for underwater communication in both existing and new areas.

LED Signals🔗

  • No green light: Power is off.

  • Flashing green light (every 3 seconds): Modem is trying to pair with another modem.

  • Fixed green light: Modem has sync with another modem. The LED will blink each time it receives a packet from the other modem (once a second).

Wiring interface🔗

The tables below shows the pinning of the Modem-M64 interface. Depending on which cable type is used, the power wires may have different colors.

Interface Color (Belden) Color (4TP1P)
Positive (10-18V) Orange Red
Negative/Ground Orange/White Black
UART RX Brown Brown
UART TX Brown/White Brown/White

Note

Power must be applied to the power terminals before applying voltage to UART pins

Terminal Interface🔗

The Modem-M64 has a 3.3 volt UART interface.

Settings Value
Baud rate 115200
Data parity stop 8N1
Flow control None

Channels🔗

Modem M64 supports channels 1-7.

From (kHz) To (kHz) Channels using this frequency band
31.25 62.25 1
62.25 93.75 2 (16)
93.75 125.00 3 (16)
125.00 156.00 4 (17)
156.00 187.00 5 (17)
187.00 218.00 6 (18)
218.00 250.00 7 (18)

Please note that the Underwater GPS Explorer kit channels 16, 17, 18 overlaps and all channels overlaps with Underwater GPS G2.

Libraries and code examples🔗

Example code and libraries that can be used to communicate with the modem on the terminal interface:

Dimensions🔗

modem_m64_dimensions