The following is an example of a Middleman instance being created, unimaginatively named middleman.
middleman = Middleman()NOTE: The path of the libraries are relative to where the file is being run, not where the file is located.
The method collect_data() returns all the necessary data required in a tuple. The following is an example of it being called by the middleman instance.
(co2, voc, temp, humidity, ambient_temp, error) = middleman.collect_data()CCS811 Air Quality Sensor
- co2 (equivalent calculated carbon dioxide concentration): 400-8192ppm
- voc (Total Volatile Organic Compound): 0-1187ppb
TMP006 Temperature Sensor
- temp (Temperature): -40 - +125°C
SI7021
- Humidity: 0-80%
- ambient_temp (Ambient Temperature): -10 - +85°C
Each bit in the error code represents an independent error. They are normally all 0's, but the relevant bit(s) is toggled to 1 upon an error. By design, these errors do not disturb the operation of the devices.
"Out of range" errors automatically reset to 0 when the value returns within the range.
| Sensor | Bit | Error |
|---|---|---|
| CCS811 | 9 | Data out of range. |
| CCS811 | 8 | Hardware ID or version is incorrect. |
| CCS811 | 7 | I2C error. |
| CCS811 | 6 | No valid firmware application is loaded. |
| TMP006 | 5 | Data out of range. |
| TMP006 | 4 | Manufacturer or device ID is incorrect. |
| TMP006 | 3 | Operation mode is invalid. For example, configuration register specified inactive, or invalid ADC (analogue digital conversion) rates. |
| SI7021 | 2 | Data out of range. |
| SI7021 | 1 | Device ID incorrect. |
| SI7021 | 0 | Invalid device firmware. |