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STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 10:16 am
by jxid
Hi to all
I have an STM32F103 (blue pill) and i want to connect with a BME280 sensor in order to develop a project.
I want to read temperature , humidity and pressure from the sensor.
I use I2C protocol for my sensor.
After some search i found that the sensor could connect to B8,B9 of the STM module (B8---SDA , B9---SCL)
I used Adafruit BME280 library.
But since now i can not get data from sensor.I get only zeros.
The project compiles OK with no errors.
I use Arduino IDE .
Here is my sample code:
Code: Select all
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
Adafruit_BME280 bme;
void setup()
{
Serial.begin(115200);
bme.begin();
}
void loop()
{
Serial.println(bme.readTemperature(),1);
Serial.println(bme.readHumidity(),1);
Serial.println(bme.readPressure(),1);
delay(1000);
}
The sensor works fine with ESP32 , ESP8266 Arduino Nano and Arduino UNO R3 boards.
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 10:47 am
by stevestrong
Some basics:
viewtopic.php?f=2&t=301
Which core do you use?
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 11:30 am
by jxid
I tried the scanner code from the above link.
It does not detect my BME280 sensor.
But when i connect an RTC module it finds it.
What am i doing wrong?
Any ideas?
My STM32 board is STM32F103C8T6
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 11:49 am
by fpiSTM
You didn't answer the question:
which core do you use?
https://github.com/stm32duino/Arduino_Core_STM32
or
https://github.com/rogerclarkmelbourne/Arduino_STM32
or other...
If you don't provide enough information you will not be able to get help from the community.
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 2:14 pm
by jxid
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 2:40 pm
by mrburnette
It has been years, but I did an I2C, SPI, GPS serial using a Maple Mini and all worked as expected:
https://www.hackster.io/rayburne/color- ... ock-a8b121
Recently, I used a Blue Pill for just the barometer/ILI9341, so no issues with I2C or SPI.
Have you implemented pull-up resistors for I2C? If the scanner sw cannot see the I2C device but detects another... well, it is something 'external' to the uC IMO. Some I2C device modules have integrated pull-up resistors on the breakout board.
Ray
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 2:54 pm
by jxid
Thanks Ray.
I have used this with a M7N gps module and an TFT display with no problem.
But i have problem with BME280 sensor.
Is there any other library for BME280 to use or to do any modifications?
Also i see that in your barometer project you use 15,16 pin in STM32 for SDA and SCL.That means that you connect the sensor to A5 and A6 pins.
I use B6 and B7 or B8 and B9 pins.
Is this right?
I tried to connect the sensor to A5 and A6 pins with pull-up resistors.
The result is the same.Only zeros in serial monitor.
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 3:10 pm
by mrburnette
The Master Pin Map will show which pins can be interchanged in the switch matrix fabric:
http://docs.leaflabs.com/docs.leaflabs.com/index.html go down page...
Blue Pill specifics:
https://stm32duinoforum.com/forum/wiki_ ... _Pill.html
Is there any other library for BME280 to use or to do any modifications?
I cannot answer. Maybe a Google site-centric search?
Also, some of the nice color-coded graphic pinouts are nicely done:
I am forgetful if any of the common libraries restrict pin substitution.
I use B6 and B7 or B8 and B9 pins.
Best to use full port name: PB6, PB7, etc.
Ray
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 3:20 pm
by jxid
I have this pin out diagram and i connect the sensor acording to this.
That's why i use PB6-PB9 pins , because as shown in the diagram is for SDA and SCL.
But no luck till now.
Anyway thanks for the help and usefull info.
Re: STM32F103 and BME280 Sensor
Posted: Mon Apr 20, 2020 3:51 pm
by jxid
After some test i made it work!
So my results:
The sensor can be found with ID 0x76 ony when is connected to pins PB7---SDA and PB6---SCL
I hsd to "set" the adddes to bme.begin() like bme.begin(0x76)
Then the sensor work fine.
This is my working code:
Code: Select all
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
Adafruit_BME280 bme;
void setup()
{
Serial.begin(115200);
bme.begin(0x76);
}
void loop()
{
Serial.print("Temperat: ");
Serial.println(bme.readTemperature(),1);
Serial.print("Humidity: ");
Serial.println(bme.readHumidity(),1);
Serial.print("Pressure: ");
Serial.println((bme.readPressure()/100),1);
delay(1000);
}
Thank you for your help.
Yannis.