User manual

Table Of Contents
Flash card
Figure 3-3: MMP Rev D Flashcard
The middle circuit board is a TattleTale 8 (TT8v2) microcontroller manufactured by
Onset Computer Corporation (www.onsetcomp.com). The TT8v2 controls power and
communications for the MMP hardware.
The bottom circuit board is the motherboard of the MMP controller. As illustrated in
Figure 3-2, peripheral components like the motor and sensors connect to the controller through
the black edge connectors. This bottom circuit board also supports power distribution and an
independent watchdog circuit. The watchdog is described in more detail in Chapter 7, “MMP
User Interface” and Appendix B, “System Architecture”.
Over time, a layer of particles and oils may accumulate on the connector contact surfaces,
producing an oxide layer which interferes with electrical operation. Remove the particles by
disconnecting and reinserting the connectors or using cleaning spray for electrical contacts.
NOTE
Before a deployment, manually verify that the connectors are fully inserted and locked.
The MOTOR connector on the bottom circuit board is the output of a standard H-bridge
and provides a directional drive voltage to the DC brushless motor. The drive circuit is designed
to protect against the back EMF voltages that are generated when the motor is driven by the
mooring during launch and recovery operations or if the MMP encounters an obstruction during a
profile.
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