pHAT Module Series

pHAT-RV Technical Description

pHAT-RV Technical Description

Page 9 of 27

3 Application

3.1 Stepper Motor Connection

The stepper motor connections are marked ‘MOTOR 1’ to ‘MOTOR 4’ and consist of a five (5)

pin JST ZHR 1.5mm pitch connector, see section 3.4.3 for pinning.

This connection is standard for most 24mmD stepper motors, such as the DS-STMOT1, but

there is also a pre-made 200mm JST ZHR cable available, DS-STCAB1, and the JST ZHR mating

receptacle and pins are also available from Farnell electronics as items 2078162 and 1830898

respectively.

Most unipolar stepper motor phases are wired as follows:

It is recommended that you double check your motor phase connections before power

application. Six wire stepper motors are also supported by connecting the two centre taps

both to MOTOR +.

3.2 Servo Motor Connection

The servo motor connections are marked ‘SERVOS’ from 1 to 4 and consist of three pins

marked ‘GND’, ‘V+’ and ‘SV’. Analogue servos should be connected to these pins, noting

polarity, BLACK is normally GND, see section 3.4.4 for pinning.

3.3 Raspberry-Pi Board Support

The RV supports all of the current Raspberry-Pi board versions. However, when powering a

Raspberry-Pi from the RV there is a 1A power limitation on the 5V supply from the RV. This

means that some Raspberry-Pi boards such as the newer Model 3 B & B+ may struggle to

operate correctly especially when other peripherals such as USB keyboards/mice/drives are

connected. The RV is not designed for these types of applications and the 5V supply will shut-

down if overloaded.

3.4 Operation

When the Lithium Battery is connected to the XT60 connector 5V power will be delivered to

the connected Raspberry-Pi board and it will boot normally.

A

A

B

B

MOTOR +