User manual

PICDEM™ Lab II Development Board User’s Guide

DS40001814A-page 12  2015 Microchip Technology Inc.

1.5 CONNECTING THE USB I

C/ASYNC COMMUNICATIONS

There are two connections to the on-board USB I

C/ASYNC interface: the first is a USB

mini-B connector J18, and the second is the on-board connector J4. A standard USB

cable should be plugged into J18 and the PC/Apple computer to be used as an

interface. If the driver for the MCP2221 has not been loaded, it should be loaded prior

to connecting to the PICDEM Lab II Development Board. See Section 2.2 for

information concerning the installation of drivers and terminal programs.

To connect to the on-board connector J4, four connections must be made. Pins 2 and

3 of J4 should be connected to V

DD (5V, 3.3V or V

VAR

) and VSS of the target circuit.

This will set the high and low voltage outputs for both the I

C and ASYNC interfaces.

Pins 1 and 6 of J4 should connect to the Rx and Tx connections, respectively, of the

circuit being developed (pin 1 is Tx out of the interface and pin 6 is Rx into the inter-

face). Alternately, pins 4 and 5 of J4 should connect to SDA and SCL, respectively, of

the circuit being developed. The interface does not provide any pull-up resistors on

either SDA or SCL, so the circuit being developed should include appropriate pull-up

resistors for the I

C interface.

1.6 INSTALLING MikroElektronika CLICK™ BOARDS

To install a Click board in the PICDEM Lab II Development Board, orient the Click board

such that pin 1 faces away from the solderless prototyping block, align the Click board

pins with the socket and press the board downward firmly until the pins fully seat in the

sockets.

Connections between the power supply voltages (+5V, +3.3V and GND) and the Click

board sockets are already present. It is left to the user to make connections between

the Click board control interface and the appropriate pins of the microcontroller. The

pinout of the Click boards is included below for reference.

Figure 1-3 lists the connections to the MikroElektronika Click boards.

FIGURE 1-3: PINOUT SPECIFICATIONS