Lua library for BME280 environmental sensor for FlashAir.
Tested on this GY-BME280 module with BME280 and FlashAir W-04 v4.00.03.
GY-BME280 has 10korm pull-up register for SCL, SDA, CSB.
And it has 10korm pull-down register for SD0.
So, register is not necessary.
| GY-BME280 module | FlashAir(Pin#) | Power | Memo |
|---|---|---|---|
| SD0 | CLK (5) | CLK pull-down in module | |
| SCL | CMD (2) | SCL pull-up in module | |
| SDA | DAT0(7) | SDA pull-up in module | |
| --- | DAT1(8) | ||
| --- | DAT2(9) | ||
| --- | DAT3(1) | ||
| CSB | --- | CSB pull-up in module | |
| VCC | VCC (4) | 3.3V | |
| GND | VSS(3,6) | GND |
SlibBME280.lua -- Copy to somewhere in Lua's search path.
Please see the BME280 datasheet for details.
Controls the sensor mode of the device
| mode | Mode |
|---|---|
| 0 | Sleep mode |
| 1 2 |
Forced mode |
| 3 | Normal mode |
Controls inactive duration tstandby in normal mode
| t_sb | tstandby [ms] |
|---|---|
| 0 | 0.5 |
| 1 | 62.5 |
| 2 | 125 |
| 3 | 250 |
| 4 | 500 |
| 5 | 1000 |
| 6 | 10 |
| 7 | 20 |
Controls the time constant of the IIR filter
| filter | Filter coefficient |
|---|---|
| 0 | Filter off |
| 1 | 2 |
| 2 | 4 |
| 3 | 8 |
| 4 others |
16 |
Controls oversampling of temperature data
| osrs_t | Temperature oversampling |
|---|---|
| 0 | Skipped |
| 1 | oversampling x1 |
| 2 | oversampling x2 |
| 3 | oversampling x4 |
| 4 | oversampling x8 |
| 5 others |
oversampling x16 |
Controls oversampling of pressure data
| osrs_p | Pressure oversampling |
|---|---|
| 0 | Skipped |
| 1 | oversampling x1 |
| 2 | oversampling x2 |
| 3 | oversampling x4 |
| 4 | oversampling x8 |
| 5 others |
oversampling x16 |
Controls oversampling of humidity data
| osrs_h | Humidity oversampling |
|---|---|
| 0 | Skipped |
| 1 | oversampling x1 |
| 2 | oversampling x2 |
| 3 | oversampling x4 |
| 4 | oversampling x8 |
| 5 others |
oversampling x16 |
If sadr is nil, it will scan the target address.
If other parameter is nil, default values is used.
| command | description <nil for default> |
|---|---|
| res = BME280:setup( sadr, frq, mode, t_sb, filter, osrs_t, osrs_p, osrs_h) or res = BME280:setup{ sadr=xx, frq=xx, mode=xx, t_sb=xx, filter=xx, osrs_t=xx, osrs_p=xx, osrs_h=xx} example: res = BME280:setup() |
Setup BME280 res: Same as return value of fa.i2c(). sadr: I2C target address (7bit) <auto scan> frq: I2C clock frequency. (45 or 100 or 189 or 40) <400> mode: Controls the sensor mode of the device. <3> t_sb: Controls inactive duration tstandby in normal mode. <0> filter: Controls the time constant of the IIR filter. <4> osrs_t: Controls oversampling of temperature data. <2> osrs_p: Controls oversampling of pressure data. <1> osrs_h: Controls oversampling of humidity data. <5> |
| res, temp, humi, pres, alti, thi = BME280:readData( pres_sea ) example: res, temp, humi, pres = BME280:readData() |
Read environmental value res: Same as return value of fa.i2c() temp: temperature [DegC] (-45..85) humi: humidity [%rH] (0..100) pres: pressure [hPa] (300..1100) alti: altitude [m] thi: temperature-humidity index [%] (0..100) pres_sea: sea-level pressure[hPa] <1013.25> |