https://github.com/wrclark/bme680

C implementation of BME680 with pressure, temp, hum and gas resistance
https://github.com/wrclark/bme680

bme680 bosch bosch-sensor c i2c linux raspberry-pi raspberry-pi-3 raspberry-pi-4 raspberrypi spi

Last synced: 2 months ago
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C implementation of BME680 with pressure, temp, hum and gas resistance

• Host: GitHub
• URL: https://github.com/wrclark/bme680
• Owner: wrclark
• Created: 2023-12-22T09:58:48.000Z (about 1 year ago)
• Default Branch: master
• Last Pushed: 2024-08-24T20:29:01.000Z (4 months ago)
• Last Synced: 2024-09-28T10:04:20.510Z (3 months ago)
• Topics: bme680, bosch, bosch-sensor, c, i2c, linux, raspberry-pi, raspberry-pi-3, raspberry-pi-4, raspberrypi, spi
• Language: C
• Homepage:
• Size: 2.43 MB
• Stars: 0
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# bme680

Example implementation of BME680 software. The I2C/SPI drivers are meant to run on a Raspberry Pi 4.

![Raspberry Pi](.gitea/pi.png)

Connecting the purple BME680 module board to SPI:

| SPI func | BME680 Pin | Raspberry Pi Pin |

| -------- | ---------- | ---------------- |

| MISO     | "SDO"      | GPIO 9 (Pin 21)  |

| MOSI     | "SDA"      | GPIO 10 (Pin 19) |

| SCLK     | "SCL"      | GPIO 11 (Pin 23) |

| CS       | "CS"       | GPIO 8 (Pin 24)  |

### build

```sh

$ make

```

This will create demo programs `bme680_i2c` and `bme680_spi`, and logging programs `bme680_log_i2c` and `bme680_log_spi`. They all expect the pin/devices specified in `spi.c` and `i2c.c`.

The loggers spit out the following every minute:

```

2024-08-19T18:20:00+0100 22.2358 101068 65.8092 11054.4 1

```

`Date`, `Temperature °C`, `Pressure Pa`, `% RH`, `Measured Gas resistance Ω`, `Heat stability bit`

>Note: disregard measured gas resistance if the heat stability bit is not 1.

## bme680_{i2c,spi} demo output

```

par_t1: 26203

par_t2: 26519

par_t3: 3

par_p1: 35008

par_p2: -10284

par_p3: 88

par_p4: 9692

par_p5: -202

par_p6: 30

par_p7: 24

par_p8: -4

par_p9: -3469

par_p10: 30

par_h1: 794

par_h2: 1007

par_h3: 0

par_h4: 45

par_h5: 20

par_h6: 120

par_h7: -100

par_g1: 208

par_g2: 59781

par_g3: 18

range_switching_error: 19

res_heat_range: 1

res_heat_val: 46

float mode

tfine: 104906.162500

temp: 20.489485 degC

press: 100089.609193 Pa

humidity: 64.456540 % RH

gas resistance: 12100.310308 Ohm

== for heater target=300.0 and ambient temp=19.0 (degC)

=== gas_valid_r: 1

=== heat_stab_r: 1

```

## Burn-in / logging

See file `cmd/log.c` 

![Graph of gas resistance measured over time](.gitea/gas.png)

![Graph of temperature measured over time](.gitea/temp.png)

![Graph of pressure measured over time](.gitea/press.png)

![Graph of humidity measured over time](.gitea/hum.png)

Compile and run

```sh

$ make

$ mkdir data

$ stdbuf -o0 ./bme680_log_i2c 2>&1 | tee -a data/i2c.txt &

$ stdbuf -o0 ./bme680_log_spi 2>&1 | tee -a data/spi.txt &

# wait a couple of hours or days ..

$ cd plot

$ ./plot.sh

```