Fixed! - Nicla Vision minimum example for SPI communication with BME280 fails

Official Hardware Nicla Family Nicla Vision
1

Dear All,
I want to use Nicla Vision's broken out SPI interface on PE_11-PE_14 for sensor communication, but Nicla Vision cannot detect the sensor BME-280.
PE_11 is CS, PE_12=SCLK, PE_13=CIPO=MISO=SDO of BME280, PE_14=COPI=MOSI=SDA of BME280. These are conveniently levelshifted to 3.3V on the Nicla Vision board.
I use a generic GY-BME280 sensor board for 3.3V in SPI mode.
I run this minimalistic code, but it cannot detect the BME-280 sensor on Nicla Vision:

#include <SPI.h>
#include <Adafruit_BME280.h>

// Define Chip Select pin for BME280:
#define BME_CS PE_11//PE_11 for NiclaV//53 for Mega2560  

//Adafruit_BME280 bme;
Adafruit_BME280 bme(BME_CS); // hardware SPI 

void setup() {
Serial.begin(115200);
while (!Serial);  // Wait for Serial to initialize  

SPI.begin();
unsigned status = bme.begin();  
    if (!status) {
        Serial.println("Could not find a valid BME280 sensor, check wiring, address, sensor ID!");
        while (1) delay(10); // endless loop
    }
  }

void loop() {
  // Read temperature and print it
  float temperature = bme.readTemperature();
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" C");
  delay(1000);  // Wait 1 second before next read
}

If I run the same code on my Mega2560 (with CS=53), it detects the BME correctly.

Would somebody please point me in the right direction? Much appreciated!
Alf

2

Please post an annotated schematic; I’m having trouble following your explanation.

4

NiclaVision-SPI-GYBME280
NiclaVision-SPI-GYBME2801542×582 146 KB

5

OK, I fixed it. Now it works. I had the name of the Chip Select Pin wrong. I had PE_11, but correct is PIN_SPI_SS for the Chip select pin on the pad PE_11 on Nicla Vision.
Here is the correct code. The schematic is correct.

// board: tested on Nicla Vision and Nano33BLE 2025/01/15 AlfK
// works with Adafruit drivers for BME280 on I2C and SPI
/*************************************************************************/
#include <Adafruit_GFX.h> 
#include <Adafruit_SSD1306.h> 
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

#define BME_CS   PIN_SPI_SS //PIN_SPI_SS=CS=PE_11 on NiclaVision, D10 on Nano33BLE

Adafruit_BME280 bme(BME_CS);

void setup() {
  Serial.begin(9600); 
  delay(2000);// Serial Monitor needs a little time to startup.

  unsigned status;
  status = bme.begin(); // start SPI communication to BME280
    if (!status) {
        Serial.println("Could not find a valid BME280 sensor, check wiring, address, sensor ID!");
        Serial.print("SensorID was: 0x"); Serial.println(bme.sensorID(),16);
        while (1) delay(10); // loop forever
    }
}

void loop() {
  Serial.print("Temperature: ");Serial.print(bme.readTemperature(), 2);Serial.println(" degrees C");
  delay(1000); 
}