README.md

Demo spring-boot timescaledb app with Raspberry PI and I2C sensor

Used timescaledb docker image from docker hub https://hub.docker.com/r/timescale/timescaledb timescale/timescaledb:latest-pg11

Container run: docker run --name some-timescale -e POSTGRES_PASSWORD=mysecretpassword -d -p 5432:5432 timescale/timescaledb:latest-pg11

created db demosht21

CREATE TABLE conditions ( time TIMESTAMPTZ NOT NULL, temperature DOUBLE PRECISION NULL, humidity DOUBLE PRECISION NULL );
SELECT create_hypertable('conditions', 'time');

To build this spring-boot app was used docker image from docker hub https://hub.docker.com/_/openjdk amd64/openjdk:11.0.5-jdk-slim-buster (see Dockerfile)
Container run: docker run --name mybootapp -d -p 8080:8080 demosht21s

App in C language from https://github.com/leon-anavi/rpi-examples/tree/master/HTU21D/c on Raspberry Pi 3 B+ get temperature and humidity from Sensirion SHT21 sensor via I2C.
https://www.sensirion.com/en/environmental-sensors/humidity-sensors/humidity-temperature-sensor-sht2x-digital-i2c-accurate/

Form data in json-style which sending with curl as body for POST request with basic security.
Request body example: {"timestamp": 1571836945795, "temperature": 21.6, "humidity": 45.0}
Timestamp in milliseconds.
App run in cron each minute:
/home/pi/rpi-examples/HTU21D/c/HTU21D_test | curl --request POST 'server_ip:8080/api/measures' --header 'Content-Type: application/json' --header 'Authorization: Basic dXNlcjpwYXNzd29yZA==' --data @-

Request examples:

Add measures

curl --location --request POST 'localhost:8080/api/measures'
--header 'Content-Type: application/json'
--header 'Authorization: Basic dXNlcjpwYXNzd29yZA=='
--data-raw ' { "timestamp": 1571836945795, "temperature": 21.6, "humidity": 45.0 }'

Get measures from start date to end date

curl --location --request GET 'localhost:8080/api/measures?start=1571836944793&end=1571836944796'
--header 'Content-Type: application/json'
--header 'Authorization: Basic dXNlcjpwYXNzd29yZA=='