Diff pressure click

Diff pressure click carries NXP’s MPXV5010DP signal conditioned, temperature compensated and calibrated pressure sensor with two axial ports to accommodate industrial grade tubing. The click is designed to run either on 3.3V or 5V power supply. It communicates with the target microcontroller over SPI interface (CS, SCK, MISO).

Diff pressure click is designed for comparing two pressure measurements. For example, measuring the difference in the pressure of gasses in a variable diameter flow tube.

How it works

The two ports are designated as Pressure side (P1) and Vacuum side (P2). The sensor is designed to operate with a positive differential pressure where P1 > P2. The measurement range is from 0 to 10 kPa. In the temperature range between 0º and 85ºC, the sensor has a maximum error rate of 5.0%.

MPXV5010DP features

MPXV5010DP IC has an analog output. The signal passes through the onboard 22-bit ADC before being outputted through the mikroBUS SPI interface (CS, SCK, MISO).

Key features

• MPXV5010DP pressure sensor
  • Temperature Compensated over -40° to +125°C
  • 5.0% Maximum Error over 0° to 85°C
• SPI interface
• 3.3V or 5V power supply

Specification

Pinout diagram

This table shows how the pinout on Diff pressure click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin	mikroBUStm				Pin	Notes
Not connected	NC	1	AN	PWM	16	NC	Not connected
Not connected	NC	2	RST	INT	15	NC	Not connected
SPI Chip Select	CS_M	3	CS	TX	14	NC	Not connected
SPI Clock	SCK_M	4	SCK	RX	13	NC	Not connected
SPI Master Input Slave Output	MISO_M	5	MISO	SCL	12	NC	Not connected
Not connected	NC	6	MOSI	SDA	11	NC	Not connected
Power supply	+3.3V	7	3.3V	5V	10	+5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

Programming

The following code snippet initializes SPI, UART and the Diff Pressure click and reads the difference between the two pressures to the UART terminal.

 1 void main()
2 {
3     //Local Declarations
4     int32_t buffer = 0;
5     char uart_text[20] = { 0 };
6     float difference = 0;
7     status_t status;
8
9     //GPIOs
10     GPIO_Digital_Input( &GPIO_PORT_24_31, _GPIO_PINMASK_6 );
11     GPIO_Digital_Output( &GPIO_PORT_24_31, _GPIO_PINMASK_4 );
12
13     //UART
14     UART1_Init( 9600 );
15     Delay_ms(200);
16     UART1_Write_Text( "UART Initializedrn" );
17
18     // SPI
19     SPIM1_Init_Advanced( _SPI_MASTER_CLK_RATIO_4, _SPI_CFG_PHASE_CAPTURE_RISING |
20                          _SPI_CFG_POLARITY_IDLE_LOW | _SPI_CFG_SS_AUTO_DISABLE |
21                          _SPI_CFG_FIFO_DISABLE, _SPI_SS_LINE_NONE );
22     Delay_ms(200);
23     UART1_Write_Text( "SPI Initializedrn" );
24
25     //Diff Pressure Click
26     diff_pressure_init();
27     UART1_Write_Text( "Diff Pressure Click Initializedrn" );
28
29     while (1)
30     {
31         status = diff_pressure_read_adc( &buffer );    //Read ADC
32         if ( status == OK )
33         {
34             //Get Pressure Difference
35             difference = diff_pressure_get_kpa_difference( buffer );
36             //Write it out
37             UART1_Write_Text( "KPA Difference: " );
38             FloatToStr( difference, uart_text );
39             UART1_Write_Text( uart_text );
40             UART1_Write_Text( "rn" );
41             buffer = 0;
42         }
43         else if ( status == OVH )   //Overflow High
44             UART1_Write_Text( "Overflow happenedrn" );
45         else if ( status == OVL )   //Overflow Low
46             UART1_Write_Text( "Underflow happenedrn" );
47         else                        //Data wasn't ready
48             UART1_Write_Text( "Not Readyrn" );
49
50     }
51
52 }

Code examples that demonstrate the usage of Diff press click with MikroElektronika hardware, written for mikroC for ARM, AVR, dsPIC, PIC and PIC32 are available on Libstock