KAmod BMP280

Description

KAmod BMP280 - Precise pressure and temperature sensor with SPI and I2C interface
KAmod BMP280 contains a precise BMP280 sensor manufactured by Bosch Sensortec, which allows for measuring atmospheric pressure and temperature. All key signals of the miniature BMP280 sensor have been output on the module board, which facilitates its use in modular applications. Communication takes place via SPI or I2C interfaces equipped with control voltage translation circuits.

Basic parameters

Power supply 2...5 V
Contains a precise BMP280 sensor manufactured by Bosch Sensortec
Pressure measurement range: 300...1100 hPa
Temperature measurement range: -40...+85°C
Allows measurement of atmospheric pressure and temperature
Communication takes place via SPI or I2C interfaces
Communication interfaces equipped with voltage translation circuits

Standard equipment

Code	Description
KAmod BMP280	Assembled and started module 1 x straight goldpin strip 8-pin raster 2.54 mm

Schematic

Signal layout on the board

Marking	Function
VIN	Power input 2...5 V, positive pole
VDD	Sensor power supply voltage output
SI/GND	Power supply ground – negative pole
SC/SI/SDA	SPI serial data input or SDA data line for I2C
SC/SCL	SPI and I2C clock signal
SDO	SPI serial data output or I2C address selection
CSB	CS Signal - Chip Select for SPI or I2C interface selection if connected to VDD

All module signals are led out on a 1-row J1 connector with a 2.54 mm pitch. The arrangement of individual signals is described on the bottom side of the module board (Bottom) and in the drawing:

Communication interfaces

The BMP280 sensor provides two communication interfaces: SPI or I2C. The SPI interface can operate in a 4-wire or 3-wire configuration. Detailed information on communication is included in the BMP280 system documentation.

All control signals of the KAmod BMP280 module are equipped with voltage translation circuits and can work with systems whose interfaces operate with a voltage of 2...5 V.

4-wire SPI interface
Marking	Function, connection method
VIN	Power input 2...5 V, positive pole
GND	Power ground – negative pole
SI/SDA	Data input, connect to MOSI SPI uC interface
SC/SCL	Clock signal input, connect to SCLK SPI uC
SDO	Data output, connect to MISO SPI uC interface
CSB	CS - Chip Select signal input, connect to CE SPI uC interface

3-wire SPI interface
Marking	Connection method
VIN	Power input 2...5 V, positive pole
GND	Power ground – negative pole
SI/SDA	Data input/output, connect to SDI/SDO (DI/DO) SPI uC interface
SC/SCL	Clock signal input, connect to SCK SPI uC
SDO	Not connected
CSB	CS - Chip Select signal input, connect to CE SPI uC interface

I2C interface
Marking	Connection method
VIN	Power input 2...5 V, positive pole
GND	Power ground – negative pole
SI/SDA	Data input/output, connect to SDA I2C uC interface
SC/SCL	Clock signal input, connect to SCL I2C uC
SDO	Input, address selection: connected to GND – I2C address = 0x76 connected to VDD – I2C address = 0x77
CSB	Input, interface selection, for I2C connect to VDD

Power supply

The KAmod BMP280 module can be powered by a DC voltage of 2...5 V.
The VDD pin provides voltage from the output of the 3.3 V voltage regulator placed on the board. Its value is 3.3 V when the power supply is connected to the VIN pin with a value of 3.5...5 V. However, with a lower power supply, the voltage at the VDD output will be close to the voltage at VIN.

Dimensions

The dimensions of the KAmod BMP280 board are 24x15 mm. There are 2 mounting holes with a diameter of 3.2 mm on the board.

Test program

The test program was written in the Arduino environment for the KAmodESP32 POW RS485 board. The KAmod BMP280 sensor module was connected via the I2C interface.

//example code for KAmodESP32 POW RS485 and KAmod BMP280
//ino board: ESP32-WROOM-DA Module
//additional wires:
//BMP280 SDO -> GND
//BMP280 CSB -> VDD (3.3V)
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_BMP280.h>
//LED
#define LED_PIN 2
#define MY_DELAY 2000
//I2C
#define I2C_SDA 33
#define I2C_SCL 32
//SPI
#define SPI_MOSI 13
#define SPI_MISO 12
#define SPI_SCK 14
#define SPI_CS 15
TwoWire I2CBMP = TwoWire(0);
Adafruit_BMP280 bmp280(&I2CBMP);
int status;
int i;
void setup() {
Serial.begin(115200);
Serial.println("\r\r\rHello. KAmod BMP280 test start");
pinMode(LED_PIN, OUTPUT);
digitalWrite(LED_PIN, HIGH);
I2CBMP.begin(I2C_SDA, I2C_SCL, 100000);
status = 0;
while (status == 0){
status = bmp280.begin(0x76);
Serial.print("SensorID was: 0x"); Serial.println(bmp280.sensorID(),16);
if (!status) {
Serial.println(F("Something wrong..."));
delay(3000);
}
}
bmp280.setSampling(Adafruit_BMP280::MODE_NORMAL, /* Operating Mode. */
Adafruit_BMP280::SAMPLING_X2, /* Temp. oversampling */
Adafruit_BMP280::SAMPLING_X16, /* Pressure oversampling */
Adafruit_BMP280::FILTER_X16, /* Filtering. */
Adafruit_BMP280::STANDBY_MS_500); /* Standby time. */
}
void loop() {
i++;
digitalWrite(LED_PIN, (i&1));
Serial.print(F("Temperature = "));
Serial.print(bmp280.readTemperature());
Serial.print(" *C; ");
Serial.print(F("Pressure = "));
Serial.print(bmp280.readPressure());
Serial.println("Bye");
Serial.println();
delay(MY_DELAY);
}