PGA460 Control Based on MSPM0 for Distance Detection

Abstract

This application note describes a distance detection solution based on the PGA460 and MSPM0C1104. This solution includes related evaluation steps and sample code.

Project collateral discussed in this application note can be downloaded from the following URL: https://www.ti.com/lit/zip/slaaem0.

Trademarks

LaunchPad™ and Code Composer Studio™ are trademarks of Texas Instruments.

Arm® and Cortex® are registered trademarks of Arm Limited (or its subsidiaries) in the US and/or elsewhere.

Windows® is a registered trademark of Microsoft Corporation in the United States and other countries.

All trademarks are the property of their respective owners.

1 Introduction

The PGA460 device is a highly-integrated system on-chip ultrasonic transducer driver and signal conditioner with an advanced DSP core. MSPM0C110x are part of the MSP highly-integrated ultra-low-power 32-bit microcontroller unit (MCU) family based on the enhanced Arm® Cortex®-M0+ core platform operating at up to 24-MHz frequency. The MSPM0C110x can serve as the main controller for the PGA460, providing it with configuration parameters and operating modes based on serial peripheral interface (SPI) communication, and transmitting the measurement result of PGA460 to PC.

This application report provides the evaluation steps and sample code (https://www.ti.com/lit/zip/slaaem0) for PGA460 base on the MSPM0C1104. You can also find it under SDK with this address: C:\ti\mspm0_sdk_x_xx_xx_xx\examples\nortos\LP_MSPM0C1104\demos\pga460_control_spi.

2 Hardware Introduction

To evaluate the solution based on PGA460 and MSPM01104, the following hardware elements are required:

BOOSTXL-PGA460 (PGA460-Q1 ultrasonic sensor signal conditioning evaluation module with transducers)
LP-MSPM0C1104 (MSPMC1104 LaunchPad™ development kit for 24-MHz Arm® Cortex®-M0+ MCU)
A computer with Windows® 7 or later, and .NET Framework 4.5
Micro-USB to USB cable (included with the purchase of LP-MSPM0C1104)

In the solution, MSPM0C1104 acts as the main controller to configure PGA460 via SPI, and sends the measurement results to PC via universal/asynchronous receiver/transmitter (UART). Figure 2-1 shows the simply system block diagram.

Figure 2-1 System Block Diagram

PGA460-Q1 support multiple communication interfaces, including USART, TCI, SPI and One-Wire UART. USART Synchronous Mode is identical to a SPI without a chip select because the addressing is handled by the three-bit UART_ADDR value to enable up to eight device son a single bus. In this solution, the three-wire SPI communication interface was used on MSPM0C1104 to control PGA460. To enable SPI communication module in PGA460, pull down P18(COM_P) and pull up P17(COM_S), P37(MHLD), P36(MCS) on PGA460. This is realized by controlling PA2, PA17 and PA23 on MSPM0C1104. The power supply (5V, 3V3, GND) and SPI (MOSI, MISO, Clock) can be connected correspondingly. All the hardware connection between PGA460 EVM and LP-MSPM0C1104 is shown in Table 2-1.

Table 2-1 Hardware Connection

Connection Type	Connection Name	LP-MSPM0C1104 Pin Number: Pin Name	BOOSTXL-PGA460 Pin Number: Pin Name
SPI	SPI: MOSI	PA18: SPI_PICO	P10: MOSI
	SPI: MISO	PA4: SPI_POCI	P9: MISO
	SPI: Clock	PA11	P34: SCLK_LP
SPI enable	COM_PD	GND	P18: COM_P
	COM_SEL	PA2	P17: COM_S
	MEM_HOLD	PA17	P36: MHLD
	MEM_CS	PA23	P37: MCS
Power connections	Power: 3.3V	J1:3V3	P1: 3V3
	Power: 5V	J3:5V	P21: 5V
	Power: Ground	GND	P22: GND

The final setup is shown in Figure 2-2.

Figure 2-2 Hardware Setup