Getting Started with the PCA9846PW-ARD Evaluation Board

2.1 Board Features

• Equipped with four I²C EEPROMs for rapid test and measurements
• Equipped with programmable power supply for logic level combination
• On-board I²C-bus external connector (channel 3 and 4)
• 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 dev. 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 PCA9846PW-ARD daughter board (see IMX8MMINI-IARD user manual).

2.2 Board Description

The evaluation board is built around the PCA9846, four channel ultra-low voltage, FM + I²C-bus switch with reset. 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 / mother boards with the purpose of testing and measuring the characteristics of the PCA9846 device under test (DUT).

2.3 Kit Featured Components

Overview of the PCA9846PW-ARD board

3.1 Install and Configure Software Tools

PCA9846PW-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/development board benefits by firmware support which can be downloaded from the NXP company site. Before starting, the EVK motherboard must be programmed with the corresponding firmware package. Additionally, a GUI application (Windows 10) is available for download from the NXP site, allowing rapid testing and operation of PCA9846PW-ARD daughter board through the one of above mentioned EVK.

Once the software is installed, the first step is to select the correct combination EVK – PCA9846PW-ARD daughter card and then the board can be controlled from the GUI interface.

4.1 IMXRT1050 EVK Board

Figure 1 shows the required hardware for operation of the PCA9846PW-ARD daughter board with IMXRT1050 EVK. The following items are necessary:

• One IMXRT1050-EVK board
• One PCA9846PW-ARD daughter board
• One USB-A / USB Micro-B cable
• A PC with Windows 10 operating system

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

• Connecting an external 5.0 V DC power supply to the barrel power connector (J2) on the board
• Connecting a USB cable from the PC to the Micro-B USB connector (J9) on the board
• Connecting a 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’s guide.

Figure 1: PCA9846PW-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 PCA9846PW-ARD daughter card on the Arduino connector of the EVK (see Figure 2)
3. Using USB connector J28, connect the EVK board to a USB port of the computer
4. Install the IMXRT1050 target firmware (download from NXP site and see UM11581, Arduino shields GUI and firmware installation manual  for step-by-step instructions)
5. Install GUI application (see UM11581, Arduino shields GUI and firmware installation manual )
6. Open the GUI application to operate the device from the PC

Figure 2 shows the boards during the operation

Figure 2: The assembly PCA9846PW-ARD daughter board / IMXRT1050 EVK board operation

4.2 LPCXpresso55S69 Development Board

Figure 3 shows the required hardware for operation of the PCA9846PW-ARD and LPCXpresso55S69 EVK board. This configuration consists of:

• One LPCXpresso55S69 EVK board
• One PCA9846PW-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.

Figure 3: PCA9846PW-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 PCA9846PW-ARD daughter card to P16 – P19 connectors located on LPCXpresso55S69 development board (see the marked pins of P16 – P19, Figure 3)
2. Connect the development board using port P6 USB port of PC
3. Install the LPCXpresso55S69 target firmware (download from NXP site and read the EVK_Firmware_And_GUI_Install_Guide_For_Arduino_Boards.pdf 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

Figure 4: PCA9846PW-ARD daughter board / LPCXpresso55S69 mother board operation

4.3 i.MX 8M Mini LPDDR4 EVK Board

When an i.MX 8M Mini LPDDR4 EVK board is used with the PCA9846PW-ARD 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 PCA9846PW-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 PCA9846PW-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 PCA9846PW-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.

To power-up the EVK, a USB-C type cable connected to PORT 2 of the EVK is used. 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 a 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.

Figure 5: The assembly PCA9846PW-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 PCA9846PW-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 6)
3. Power-up the EVK board using a USB Type C cable attached to PORT 2
4. Connect the EVK to the PC, using a 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 (download UM11581, Arduino shields GUI and firmware installation manual  from NXP site)
7. Install GUI application on the PC (see the instruction file referred in the above step)
8. Open the GUI application to operate the device from the PC

Figure 6: PCA9846PW-ARD daughter board / i.MX 8M Mini LPDDR4 EVK board operation

4.4 Another Device

The PCA9846PW-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 and an EVK without Arduino port. In the first case, a firmware shall be developed according to NTS0304E specifications and then simply attach PCA9846PW-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 it is compliant with IC specifications. Use NTS0304E data sheet to read details about internal registers of the DUT IC and data exchange between internal controller and the EVK. Make sure that the electrical connections are accurate and avoid data conflicts on the signal lines to prevent IC damage.