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SPI Example

Description

The Example4_SPIFunctionality.ino example file can be accessed from the File > Examples > SparkFun STHS34PF80 Arduino Library > Example4_SPIFunctionality drop-down menu. This example operates similarly to the code in Example1_BasicReadings.ino. Instead of retrieving data through the I2C interface, the serial peripheral interface (SPI) is used to access the human presence detection values from the STHS34PF80 sensor.

Example4_SPIFunctionality.ino
Code Verification

This code was last verified to be functional under the following parameters:

  IDE: Arduino 2.2.1
  Hardware Platform: SparkFun RedBoard Qwiic    
  SparkFun Human Presence and Motion Sensor - STHS34PF80 (Qwiic) Version: 1.0
  SparkFun Qwiic Mini Human Presence and Motion Sensor - STHS34PF80 Version: 1.0

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/******************************************************************************
  Example4_SPIFunctionality.ino

  Read human presence detection values from the STHS34PF80 sensor, print them
  to terminal using SPI communication instead of I2C. 
  Prints raw IR presence (cm^-1), if motion was detected, and temperature 
  in degrees C.

  SparkFun STHS34PF80 Arduino Library
  Madison Chodikov @ SparkFun Electronics
  Original Creation Date: September 19th, 2023
  https://github.com/sparkfun/SparkFun_STHS34PF80_Arduino_Library

  Development environment specifics:

  IDE: Arduino 2.2.1
  Hardware Platform: SparkFun RedBoard Qwiic    
  SparkFun Human Presence and Motion Sensor - STHS34PF80 (Qwiic) Version: 1.0
  SparkFun Qwiic Mini Human Presence and Motion Sensor - STHS34PF80 Version: 1.0

  Do you like this library? Help support SparkFun. Buy a board!

    SparkFun Human Presence and Motion Sensor - STHS34PF80 (Qwiic)
    https://www.sparkfun.com/products/22494

    SparkFun Qwiic Mini Human Presence and Motion Sensor - STHS34PF80
    https://www.sparkfun.com/products/23253

  Hardware Connections:
  Wire the SPI Connections from the RedBoard Qwiic to the STHS34PF80 Breakout 
  with a resistive divider using the header pins like so: 

  ARDUINO --> STHS34PF80
  SCK/SCL (13) --> Clock
  SDI/SDA (12) --> Data in
  !CS (10) --> Chip Select
  3.3V --> 3.3V
  GND --> GND

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/

#include "SparkFun_STHS34PF80_Arduino_Library.h"
#include <SPI.h>

STHS34PF80_SPI mySensor; 

// Presence and Motion variables to fill
int16_t presenceVal = 0;
float temperatureVal = 0;

// Set your chip select pin according to your setup
uint8_t chipSelect = 10;

void setup()
{
    Serial.begin(115200);
    Serial.println("STHS34PF80 Example 4: SPI Functionality");

    // Configure the chip select pin
    pinMode(chipSelect, OUTPUT);
      digitalWrite(chipSelect, HIGH);

    // Begin SPI
    SPI.begin();

    // Establish communication with device 
    if(mySensor.begin(chipSelect) != 0)
    {
      Serial.println("Error setting up device - please check wiring.");
      while(1);
    }

    delay(500);
}

void loop() 
{
  sths34pf80_tmos_drdy_status_t dataReady;
  mySensor.getDataReady(&dataReady);
  Serial.println(dataReady.drdy);

  // Check whether sensor has new data - run through loop if data is ready
  if(dataReady.drdy == 1)
  {
    sths34pf80_tmos_func_status_t status;
    mySensor.getStatus(&status);

    // If presence flag is high, then print data
    if(status.pres_flag == 1)
    {
      // Presence Units: cm^-1
      mySensor.getPresenceValue(&presenceVal);
      Serial.print("Presence: ");
      Serial.print(presenceVal);
      Serial.println(" cm^-1");
    }

    if(status.mot_flag == 1)
    {
      Serial.println("Motion Detected!");
    }

    if(status.tamb_shock_flag == 1)
    {
      mySensor.getTemperatureData(&temperatureVal);
      Serial.print("Temperature: ");
      Serial.print(temperatureVal);
      Serial.println(" °C");
    }
  }
}

Hardware Connections

For this example, users will need to modify the CS jumper to enable the SPI communication. In the setups illustrated below, right-angle headers were soldered to the boards and connected with M/F jumper wires to the microcontroller. However, users should select a connection method that suits their needs.

The sensor connected to a RedBoard Plus

The sensor connected to a RedBoard Plus

The Qwiic Human Presence/Motion Sensor boards with headers soldered to them and connected to a RedBoard Plus with jumper wires.

Pin Connections

Below are the pin connections for SPI communication with the sensor. Users should be aware of the logic-levels of their microcontroller; with the RedBoard Plus, users only need to flip a switch to configure all the board's pins to 3.3V-logic.

Sensor Pin Microcontroller Pin RedBoard Plus
CS SPI - Chip Select Pin 10
SCL SPI - Serial Peripheral Clock 13
SDA SPI - Serial Data In/Out 12
3V3 Power: 1.7 to 3.6V 3.3V
GND Ground GND

Switch on the RedBoard Plus

The logic-level switch on the RedBoard Plus.

Note

Users will need to cut/disconnect the CS jumper to enable the SPI communication on the Qwiic Human Presence/Motion Sensor boards.