gRPC server/client implementation for transmitting instrumentation readings to a central data store
The instr server receives incoming connections through gRPC from clients and stores readings in a database. Currently supports PostgreSQL (see backend/database folder)
The therm client collects automated readings from a thermistor. A thermistor's resistance varies when it is heated or cooled, and the measured resistance can be converted a temperature. One application of a thermistor for civil engineering is for observing seasonal or annual trends in ground temperature.
To run the server, a PostgreSQL connection is required. The application is written in Go.
Create a database user and a database. (PostgreSQL tutorial)
Create a table with resistance and device columns:
CREATE TABLE reading(
id SERIAL PRIMARY KEY,
resistance FLOAT NOT NULL,
device TEXT NOT NULL CHECK (char_length(device) < 100)
)Set the following environment variables:
- DBHOST: the database hostname (localhost if running on the same machine)
- DBPORT: the database port (postgres default is 5432)
- DBNAME: the name of your database
- DBUSER: the database user with privileges on the database
Make sure the database is ready to accept connections and start the instrumentation server: from the backend/server folder, run go run main.go. Alternatively, build the package with go build main.go and execute the binary.
The therm client can be run on a Raspberry Pi with Docker. An ADS1015 analog to digital converter was used.
Build the executable in the clients/therm folder:
cd clients/therm
GOOS=linux GOARCH=arm go build main.goBuild the docker image:
docker build -t instr .
and run it from the Raspberry Pi (see Docker documentation for building and pushing your own images). Use the --device flag to allow the container to access /dev/i2c-1:
docker run --device=/dev/i2c-1 instr
When a collection is established, you will begin to see server responses in the client logs and thermistor readings in the server logs and database.