Getting Started with the PCAL6534EV-ARD Evaluation Board

This page will guide you through the process of setting up and using the PCAL6534EVARD board

Get to Know the Hardware

2.1 Board Features

  • I/O connector for external access to IC input-output pins
  • Five user switches connected to I/O pins of the IC
  • Eight user LEDs connected to I/O pins of the IC
  • On-board LED display controlled from the I/O pins of the IC
  • Equipped with Arduino Uno R3 port for direct connection with Arduino devices
  • Fully compliant with IMXRT1050 EVK board, including GUI (Windows 10)
  • Fully compliant with LPCXpresso55S69 development board, including GUI (Windows 10)
  • Compliant with i.MX Mini LPDDR4 EVK board, including GUI (Windows 10)

Note: For i.MX Mini LPDDR4 EVK board, it is necessary to use IMX8MMINI-IARD interposer board between the EVK and PCAL6534EV-ARD daughter board (see IMX8MMINI-IARD User Manual).

2.2 Board Description

The evaluation board is built around the PCAL6534, low-voltage translating, 34-bit I2C-bus/SMBus I/O expander with interrupt output, reset and configuration registers. The evaluation board serves as a daughter card that can be connected through an Arduino port to various Arduino compatible (including original Arduino Uno R3) EVK / motherboards for testing and measuring the characteristics of the PCAL6534 device under test (DUT).

2.3 Kit Featured Components

Overview of the PCAL6534EV-ARD board.

Overview of the PCAL6534EV-ARD board
Overview of the PCAL6534EV-ARD board

Installing and Configuring Software Tools

PCAL6534EV-ARD evaluation board is designed and built as a daughter board able to work in conjunction with a mother board equipped with an Arduino port. The board was built to be fully compatible with the following NXP evaluation (EVK) boards:

  • IMXRT1050 EVK board
  • LPCXpresso55S69 development board
  • i.MX 8M Mini LPDDR4 EVK board

Each evaluation and development board benefits by firmware support which can be downloaded from Nxp.com. Before starting, the EVK motherboard must be programmed with the corresponding firmware package. Additionally, a GUI application (Windows 10) is available for download from NXP.com, allowing rapid testing and operation of PCAL6534EV-ARD daughterboard through the one of above mentioned EVK. The GUI application is common for all three EVKs and for the PCAL6xxx I/O expander development card family, manufactured by NXP (PCAL6408A, PCAL6416A, PCAL6524 and PCAL6534 ICs).

For details regarding installation of the EVK firmware and GUI host software on PC, download install guide. Once the software is installed, the first step is to select the correct combination EVK – PCAL6534EV-ARD daughter card and then the board can be controlled from the GUI interface.

Configure the Hardware for Startup

4.1 Using the PCAL6524EV-ARD with an IMXRT1050 EVK Board

Figure 1 shows the required hardware for operation of the PCAL6534EV-ARD daughter board with IMXRT1050 EVK. The following items are necessary:

  1. One IMXRT1050-EVK board
  2. One PCAL6534EV-ARD daughter board
  3. One USB-A / USB Micro-B cable
  4. A PC with Windows 10 operating system

The IMXRT1050 EVK mother board can be powered by one of the three methods:

  • Connecting an external 5VDC power supply to the barrel power connector (J2) on the board
  • Connecting an USB cable from the PC to the micro-B USB connector (J9) on the board
  • Connecting an USB cable from the PC to the USB connector (J28) on the board. When the PC is connected in this fashion, the USB port can simultaneously act as a debug interface. Therefore, by using a single USB cable connected to J28, the EVK can be powered and at the same time linked to the PC for data exchange.

The older USB ports (from PC) are not able to deliver the necessary current (500 mA). Before establishing the communication, use an external power supply (connected to J2).

From J1 on the EVK board (see Figure 1) the user can select the power configuration for the mother board. For further details, refer to the MIMXRT1050 EVK Board Hardware User Guide.

PCAL6534EV-ARD daughter board and IMXRT1050 EVK board, before starting
Figure 1. PCAL6534EV-ARD daughter board and IMXRT1050 EVK board, before starting.


To configure the hardware and workstation, complete the following procedure:

  1. Configure the suitable power configuration of EVK (J1). If using J28 for power supply, the J1 jumper shall be placed in position 5-6. If using an external power supply (connected to J2), the jumper J1 will be placed in position 1-2.
  2. Insert the PCAL6534EV-ARD daughter card on the Arduino connector of the EVK (see Figure 1).
  3. Using USB connector J28, connect the EVK board to an USB port of the computer.
  4. Install the IMXRT1050 target firmware
  5. Install GUI application
  6. Open the GUI application to operate the device from the PC.

Figure 2 shows the boards during the operation.

 The assembly PCAL6534EV-ARD daughter board / IMXRT1050 EVK board operation
Figure 2. The assembly PCAL6534EV-ARD daughter board / IMXRT1050 EVK board operation.

4.2 Using the PCAL6534EV-ARD with an LPCXpresso55S69 Development Board

Figure 3 shows the required hardware for operation of the PCAL6534EV-ARD and LPCXpresso55S69 EVK board. This configuration consists of:

  • One LPCXpresso55S69 EVK board
  • One PCAL6534EV-ARD daughter board
  • One USB-A / USB Micro-B cable
  • A PC with Windows 10 operating system

The LPCXpresso55S69 development board is equipped with four USB Micro-B connectors: P5, P6, P9 and P10. The board can be powered through any USB port. Using P6 USB connector to connect the board to the PC simplifies the start-up operation because P6 is designated for debugging and the USB cable thus accomplishes two tasks at the same time: powering the board and serving as a data link between the EVK board and PC. For more details regarding power-up and operation of the LPCXpresso55S69 development board, see the LPCXpresso55S69/LPCXpresso55S28 Development Board User Manual.

PCAL6534EV-ARD daughter board and LPCXpresso55S69 mother board, before starting
Figure 3. PCAL6534EV-ARD daughter board and LPCXpresso55S69 mother board, before starting.


The following steps describe how to assemble, program and operate the configuration shown in Figure 3.

  1. Insert the PCAL6534EV-ARD daughter card to P16P19 connectors located on LPCXpresso55S69 development board (see the marked pins of P16P19, Figure 5).
  2. Connect the development board using port P6 USB port of PC.
  3. Install the LPCXpresso55S69 target firmware (download from nxp.com site and read the install guide instruction file.
  4. Install GUI application on PC (see the instruction file called out in the previous step).
  5. Open the GUI application to operate the device from the PC.
PCAL6534EV-ARD daughter board / LPCXpresso55S69 mother board operation
Figure 4. PCAL6534EV-ARD daughter board / LPCXpresso55S69 mother board operation.

4.3 Using the PCAL6534EV-ARD with an i.MX 8M Mini LPDDR4 EVK Board

A third board (IMX8MMINI-IARD interposer board) must be used, especially designed and built as EVK-daughter board interconnection. The EVK board i.MX 8M Mini LPDDR4 is not equipped with an Arduino port; instead it has a 2 x 20 pin expansion connector (J1003, see i.MX 8M Mini LPDDR4 EVK user manual). J1003 is a multipurpose port, containing various digital I/O lines, including specialized I2C and SPI buses. Starting from the expansion connector pin chart, an Arduino port interposer board was developed, with the role of signal-to-signal bridge between the 2 x 20 connector pins on the i.MX 8M Mini LPDDR4 EVK and the mated connectors of the Arduino port present on the PCAL6534EV-ARD daughter board.

To operate the setup, along with the EVK and the daughter board, a third board must be included in the setup assembly. Figure 5 shows the necessary boards and how these boards are connected. The configuration consists of:

  • One i.MX 8M Mini LPDDR4 EVK board
  • One PCAL6534EV-ARD daughter board
  • One IMX8MMINI-IARD interposer board
  • One USB-A / USB-C cable
  • One USB-A / USB Micro-B cable
  • A PC with Windows 10 operating system

It is recommended to attach the PCAL6534EV-ARD to the Arduino connectors of the IMX8MMINI-IARD interposer board first and then the resulting assembly to the i.MX 8M Mini LPDDR4 EVK. This can be done by plugging J1 connector located on the interposer board to J1003 connector on the EVK.

The power switch SW101 on the EVK board must be set to ON position to power-up the setup. Data communication is achieved by routing a separate USB (Micro-B type) cable from an USB port on the PC to debug port (J901) on the EVK (see Figure 5 and Figure 6.

The user may find details regarding power-up and operation of the setup assembly in 8MMINILPDDR4-EVK user manual and IMX8MMINI-IARD user manual.

The assembly PCAL6534EV-ARD daughter board, IMX8MMINI-IARD interposer board, and i.MX 8M Mini
          LPDDR4 EVK, before starting
Figure 5. The assembly PCAL6534EV-ARD daughter board, IMX8MMINI-IARD interposer board, and i.MX 8M Mini LPDDR4 EVK, before starting.


To configure and operate the setup, follow the below steps:

  1. Insert the PCAL6534EV-ARD onto the IMX8MMINI-IARD interposer board Arduino connectors (located on the top side).
  2. Attach IMXMMINI-IARD connector plug J1 (located on the bottom of the board) into J1003 expansion board located on the top side of i.MX 8M Mini LPDDR4 EVK (see Figure 5).
  3. Power up the EVK board using an USB Type C cable attached to PORT 2.
  4. Connect the EVK to the PC, using an USB Micro-B cable, attached to J901 debug port.
  5. Place SW101 in ON position to power-up the boards.
  6. Install the MIMXRT1050 target firmware
  7. Install GUI application on the PC
  8. Open the GUI application to operate the device from the PC.
PCAL6534EV-ARD daughter board / i.MX 8M Mini LPDDR4 EVK board operation
Figure 6. PCAL6534EV-ARD daughter board / i.MX 8M Mini LPDDR4 EVK board operation.

4.4 Using PCAL6534EV-ARD with Another Device

The PCAL6534EV-ARD daughter board can be operated with other EVK board, which has an Arduino port. There are two options to connect the board: using other EVK equipped with an Arduino port or an EVK without Arduino port. In the first case, a firmware shall be developed according with PCAL6534EV specifications, and then simply attach PCAL6534EV-ARD daughter board to the EVK to operate the board. In the second case, using the pin chart of Arduino connectors, make the necessary electrical connections (for power, I2C-bus and control lines), and develop the desired firmware, assuring that is compliant with IC specifications. Use PCAL6534 data sheet to read details about internal registers of the DUT IC and data exchange between internal controller and the EVK. Assure for correct electrical connections and avoid data conflicts on the signal lines to prevent IC damage.