Logging temperature, humidity and pressure

AntiLogPro OEM units are now able to log temperature, humidity and atmospheric pressure from a set of supported external environment sensors. At the same time, you can still record up to two channels of RS232 data.

This environment logging capability is now built into all current AntiLogPro firmware as standard. There is no requirement to purchase additional option packs or additional supporting hardware.

Simply connect one of the supported sensors to the AntiLogPro external I2C bus on the J3 pin header connector, switch on and you have immediate access to the sensor readings.

You can choose to log a set of sensor readings to one or more logging channels during a recording session and you can enter the rate at which you want to record them per channel (e.g. once every 10 seconds, twice a second, etc.).

You can also monitor the current temperature, humidity and atmospheric pressure readings in real time using the multiple unit display in our AntiTermPro terminal application (AntiTermPro V3.2 and later).

Only one environment sensor device is supported at a time per AntiLogPro unit. If two or more were to be fitted to the AntiLogPro external I2C bus, only the first recognised one would be used.

The following table shows all the currently supported I2C bus sensors and their capabilities. From the table, only the BME280 and MPL3150A2 sensors currently support atmospheric pressure readings. All of the devices listed are factory calibrated.

Please note we do not guarantee the measurement accuracy of third party sensors or modules. We have populated the table below with data specified in the device manufacturer's own datasheets.

Sensor	Description	Test module
Temperature and humidity sensors
SI7020	Silicon Labs SI7020-A20 Temperature: -40 to +125°C, ±0.4°C -10 to +85°C Humidity: 0 to 100%, ±4% RH (max)
SI7021	Silicon Labs SI7021-A20 Temperature: -40 to +125°C, ±0.4°C -10 to +85°C Humidity: 0 to 100%, ±3% RH (max)
SHT31	Sensirion SHT31-DIS Temperature: -40 to +125°C, ±0.2°C 0 to +90°C Humidity: 0 to 100%, ±2% RH (max)
SHT35	Sensirion SHT35-DIS Temperature: -40 to +125°C, ±0.1°C 0 to +90°C Humidity: 0 to 100%, ±1.5% RH (max)
HDC1080	Texas Instruments HDC1080 Temperature: -40 to +125°C, ±0.2°C +5 to +60°C Humidity: 0 to 100%, ±2% RH (max)
AHT10	ASAIR AHT10 Temperature: -40 to +125°C, ±0.3° Humidity: 0 to 100%, ±2% RH
Temperature, humidity and pressure sensor
BME280	Bosch Sensortec BME280 Temperature: -40 to +85°C, ±0.2°C +5 to +60°C Humidity: 0 to 100%, ±3% RH (max) Pressure: 300 to 1100 hPa, ±1 hPa (0 to 65°C)
Temperature and pressure sensor
MPL3150A2	NXP MPL3150A2 Temperature: -40 to +85°C, ±3°C -40 to +85°C Pressure: 700 to 1500 hPa, ±4 hPa (-10 to 70°C)

The following table shows I2C bus environment sensors that may work with AntiLogPro units as their communication protocol is thought to be compatible, but these devices have not yet been formally tested by Anticyclone Systems Ltd.

The environment sensor system now built into the AntiLogPro firmware has been designed from the start to be extremely easy to use. Using push fit pin header cables, you can have a working system up and running in less than a minute by using one of the readily available sensor evaluation modules which have simple pin header connections.

Before you start, you can use the AntiLogPro menu system to configure your unit to always power up in the playback menu mode so you won't have to wire up any push buttons to activate the playback menu when power is applied.

Now hook up the four wires from the J3 pin header to the sensor test module with pin header cables - ground, 3.3V, I2C clock and I2C data.

Connect a NULL modem cable to your PC and run our AntiTermPro application. Power up the unit, select the AntiTermPro multiple unit display and then the 'Env' tab and you will see the sensor readings in real time on the display.

When selected for record, environment sensor readings are written to the log file in ASCII text format for ease of use. They are a part of the built in 'Event' system which can also log button pushes, external changes on a dedicated 'EventIn' line, digital input line state and the unit supply voltage.

The sensor log events are inserted into the recording data stream for a given channel. For dual channel operation, you can choose which channel or channels require this data. Both channels have completely independent settings so you can log at different rates on different channels to suit your requirements. Event messages are time stamped by default so you automatically get a record of date and time for each measurement.

As the recorded ASCII line data is basically a collection of comma separated values (CSV), you can import the results directly into any spreadsheet for your data reporting and processing needs.