https://github.com/pascal-fb-martin/housesensor
A small web server to give access to physical sensors
https://github.com/pascal-fb-martin/housesensor
1-wire home-automation
Last synced: 3 months ago
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A small web server to give access to physical sensors
- Host: GitHub
- URL: https://github.com/pascal-fb-martin/housesensor
- Owner: pascal-fb-martin
- License: gpl-2.0
- Created: 2020-05-27T02:30:02.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2025-05-30T18:01:12.000Z (4 months ago)
- Last Synced: 2025-05-31T02:17:56.810Z (4 months ago)
- Topics: 1-wire, home-automation
- Language: C
- Homepage:
- Size: 92.8 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# HouseSensor - A Small Web Server to Access Physical Sensors
## Overview
This project provides a small web server that reports the latest values from local sensors. This project depends on [echttp](https://github.com/pascal-fb-martin/echttp) and [HousePortal](https://github.com/pascal-fb-martin/houseportal).
The original goal was to read temperature sensors from 1-wire DS18x20 devices.
## Installation
* Install the OpenSSL development package(s).
* Install [echttp](https://github.com/pascal-fb-martin/echttp).
* Install [HousePortal](https://github.com/pascal-fb-martin/houseportal).
* Clone this GitHub repository.
* make
* sudo make install
## Configuration
The list of sensors to scan is defined in file /etc/house/sensor.config.
There are two types of entry: options and sensors.
An option entry start with the keyword OPTION:
```
'OPTIONS' name value
```
A sensor line start with a driver name and is made of 4 to 5 items:
```
driver device location name [unit]
```
The only driver supported at this time is 'w1' (the Linux interface for the 1-Wire network).
For 1-Wire devices, the device is the 1-Wire ID of the sensor, e.g. 28-01162bdbf5ee or 10-000800c49886.
The location is an arbitrary user name, which is used to organize the sensors in groups. The name is the name of the sensor as reported to the outside.
A unit can be specified to accommodate sensors that have no intrinsic unit.
## Web API
The application supports the following web requests:
```
/sensor/current
```
Return JSON data that provides the latest value for each sensor.
```
/sensor/recent
```
Return JSON data that gives a list of the N most recent measurements. Each measurement comes with its own individual timestamp.
```
/sensor/history
```
Return JSON data that list all available historical files (see below).
```
/sensor/records/{file}
```
Download one historical file (in CSV format: see below).
## Historical Recording
The program records all measurements. The recordings are accumulated each day in /dev/shm/housesensor.csv (i.e. in RAM) and moved at the end of the day to /var/lib/house/sensor as YYYY-MM-DD.csv, where YYYY, MM and DD represents the day of the recording.
If the HouseSensor service is stopped, /dev/shm/housesensor.csv is moved to /var/lib/house/sensor/housesensor.csv. The same file is also copied hourly to /var/lib/house/sensor/housesensor.csv.
When the service is restarted, /var/lib/house/sensor/housesensor.csv is moved back to /dev/shm. This restores the recorded data when the OS reboots. However a system crash could cause up to one hour worth of recordings to be lost. This is a tradeoff to avoid wearing out a SD card or USB drive by rewriting the same block every minute or so.
The format of the recording is comma-separated variables, where each line represents one sensor measurement with fields in the following order:
* Timestamp (system time).
* Location of sensor (unquoted string).
* Name of sensor (unquoted string).
* Value (numeric or unquoted string).
* Unit (unquoted string).