Datasheet

UniPi

Power Requirements

There are two options of powering the UniPi board and Raspberry Pi:

• Single power source (RPi and UniPi are powered from the same power source)

• jumper JP1 mounted

• 5V DC 2A through the UniPi power connector (1.5A for UniPi + RPi requirements)

• Please note that UniPi can only provide 750mA to the RPi (max 1.1A in newest

versions of UniPi)

• Raspberry Pi micro USB power connector not used

• Dual power source (separate power source for each UniPi and Raspberry Pi)

• jumper JP1 dismounted

• Raspberry Pi powered from the micro USB port according to the RPi requirements

• 5V DC 1.5A through the UniPi power connector

Attention:

• Powering the UniPi from the Raspberry Pi is not recommended and could damage the

Raspberry Pi.

• When using the Raspberry Pi in heavy load and multiple peripherals connected we

recommend dual power source solution.

Connecting Raspberry Pi to UniPi

Before the first use plug in a CR2032 battery to the battery holder.

Connecting UniPi to Raspberry Pi is straight forward:

1. Make sure you have properly configured the power jumper – see powering requirements

2. Screw the spacers to the mounting holes of the UniPi

3. Connect the provided flat cable to the RPi connector

4. Screw the Raspberry Pi to the UniPi

5. Connect the other end of the flat cable to the RPi (make sure it is not twisted)

6. Plug in the power supply

Building blocks

Relays

Maximum relay switching power is limited to 250V AC/5A or 24V DC/5A, voltages over this limit must

be switched using external relay or contactor.

Relays are controller by the MCP23008 (address 0x20), see map of MCP’s GPIO to relays in Table 3 .

Each relay has a LED indicating its state.

There are three contacts for each relay named CO (change-over or C=connected), NO (normally

opened), NC (normally closed). By default contacts CO and NC are connected (NO is not connected),

by switching the relay on, CO gets connected to NO (NC is disconnected).

Digital Inputs

These inputs can be triggered by 5-24V DC voltage with minimum pulse length of 5ms. For easy visual

reading of their states all inputs are equipped with LED.

When using the GPIOs make sure to set a software pull-up resistor on each GPIO to make it work

properly otherwise state of the GPIO cannot be read properly.