This software is intended to receive all measurements from an OpenAir device for testing and calibration. This is more data than would be useful in most cases, hence the name 'firehose'.
This software is a commandline utility. Precompiled versions of the binary for Linux, MacOS and Windows plattform are available on the github releases page.
The software is a command line program with the following options
$ ./firehose -help
Usage of ./firehose:
-a string
address for server to listen on (default ":7531")
-addr string
address for server to listen on (default ":7531")
-csvAgeMinutes int
after how many minutes to rotate the csv file (default 10)
-dateDir
rotate logs into YYYY/MM/DD directory structure
-h print usage
-help
print usage
-o string
filename to save output to (default "-")
-outfile string
filename to save output to (default "-")
-printIP
print IP Address(es) of host
-version
print version banner and exit
By default the software listens to port 7531 on all interfaces, using this option, it can be restricted to a single IP address, e.g. the address assigned by OpenAir if connecting to the AP provided by the device.
The software receives sensor readings (currently as a TCP Stream of JSON packets) and outputs a CSV file for use in Excel, etc. By default the CSV entries are printed to STDOUT, but a filename to save the csv can be provided using the outfile parameter.
The program can receive and process output from multiple OpenAir devices. These devices must be configured to use the same server using the firehose_addr configuration parameter.
The format of the CSV is as follows:
server_time,timestamp,device_id,tag,value(hex),value(decimal),tag_annotation,value_annotation
1559312722,0,esp32_0AAEAC,0xffffffff,0x00000000,0,OA_Network_Events,CONNECT
1559312722,992,esp32_0AAEAC,0x00000009,0x0004d243,315971,OA_BME_Pressure_Raw,(raw 315971)
1559312722,992,esp32_0AAEAC,0x0000000a,0x00018e28,101928,OA_BME_Pressure,1019.28 hPa
1559312722,992,esp32_0AAEAC,0x0000000b,0x000801dc,524764,OA_BME_Temp_Raw,(raw 524764)
1559312722,992,esp32_0AAEAC,0x0000000c,0x00048d3b,298299,OA_BME_Temp,25.15 C
...
| Field | Description |
|---|---|
| server_time | Time the package was received by the server (unix timestamp, seconds since 1970-01-01) |
| timestamp | OpenAir timestamp of sensor reading on the device, seconds since device boot |
| device_id | String identifying the OpenAir device |
| tag | Tag identifying the source of the reading. For convenience this value is annotated in the field tag_annotation. A list of all tags is provided in a table below. |
| value(hex) | All sensor reading are currently stored as unsigned 32bit values. This field is a hex representation of the value. |
| value(dec) | This field is a decimal representation of the sensor value. Depending on the nature of the data returned by the sensor, this may not be a sensible representation. |
| tag_annotation | Human readable description of the tag |
| value_annotation | Human readable interpretation of the value for convenience. |
In addition to the tagged data received from the OpenAir Device, the firehose-server logs some network events and derived data using the following pseudo-tags:
| Tag | Description |
|---|---|
| OA_Network_Events | Value CONNECT and DISCONNECT signify time the OpenAir device established a connection or the connection was lost. |
| OA_AlphaCalc_1 … OA_Alpha_Calc_4 | Precalculated (server side) voltage of the ADC reading. |
This repository also contains an OpenAir Simulator for testing the firehose server without using a physical OpenAir device. It is located under cmd/simulator/openair.go