Some data loggers use a flexible scripting environment to adapt themselves to various non-standard protocols.ĭata logging versus data acquisition Another multi drop protocol which is now starting to become more widely used is based upon CAN Bus (ISO 11898). This has been used traditionally in the industrial control area, and there are many industrial instruments which support this communication standard. Some datalogging companies are also now supporting the MODBUS standard. SDI-12 also supports multi drop instruments. The use of this standard has not gained much acceptance outside the environmental industry. Several protocols have been standardised including a smart protocol, SDI-12, that allows some instrumentation to be connected to a variety of data loggers. The development of the Semantic Web and the Internet of Things is likely to accelerate this present trend. Standardisation of protocols and data formats has been a problem but is now growing in the industry and XML, JSON, and YAML are increasingly being adopted for data exchange. More complicated loggers may cost hundreds or thousands of dollars.
Simple single channel data loggers cost as little as $25. The cost of data loggers has been declining over the years as technology improves and costs are reduced. This allows for a comprehensive, accurate picture of the environmental conditions being monitored, such as air temperature and relative humidity. Upon activation, data loggers are typically deployed and left unattended to measure and record information for the duration of the monitoring period. One of the primary benefits of using data loggers is the ability to automatically collect data on a 24-hour basis. Electronic data loggers have replaced chart recorders in many applications. It is common for general purpose types to be programmable however, many remain as static machines with only a limited number or no changeable parameters.
Raspberry pi temperature and light logger software#
Some data loggers interface with a personal computer, and use software to activate the data logger and view and analyze the collected data, while others have a local interface device (keypad, LCD) and can be used as a stand-alone device.ĭata loggers vary between general purpose types for a range of measurement applications to very specific devices for measuring in one environment or application type only. They generally are small, battery powered, portable, and equipped with a microprocessor, internal memory for data storage, and sensors. Increasingly, but not entirely, they are based on a digital processor (or computer), and called digital data loggers (DDL). # Print out and log the temperature until the program is stopped.Data logger Cube storing technical and sensor dataĪ data logger (also datalogger or data recorder) is an electronic device that records data over time or in relation to location either with a built in instrument or sensor or via external instruments and sensors. # '=' into degrees Celsius, then degrees Fahrenheit # If the '=' is found, convert the rest of the line after the # Look for the position of the '=' in the second line of the # While the first line does not contain 'YES', wait for 0.2s Lines = read_temp_raw() # Read the temperature 'device file' # Convert the value of the sensor into a temperature # Finds the correct device file that holds the temperature dataĭevice_folder = glob.glob(base_dir + '28*')ĭevice_file = device_folder + '/w1_slave'į = open(device_file, 'r') # Opens the temperature device file Os.system('modprobe w1-therm') # Turns on the Temperature module Os.system('modprobe w1-gpio') # Turns on the GPIO module My new bit is at the end where it displays the temperature in the console but also writes the date/time and temperature to a file called temp.csv. One problem I had was that the Raspberry Pi can’t get on the internet until AFTER it has logged in (it requires authorisation on a web page to join the school network), so to set the clock to roughly the right time & date I used the following command:Īnd here’s the Python 3 code, modified from the CamJam EduKit code.
The temperature sensor is part of the excellent CamJam Sensors EduKit /products/camjam-edukit-2-sensors – this costs an insane £7 for a tin box containing a breadboard, jumper wires, huge LEDs, a buzzer and light-dependent resistor.ī) when the classroom filled up with studentsĬ) when those students turned their computers on I then opened the CSV file in Libre Office on the Pi and made a simple line chart. We’re taking real historical weather data, analysing it in Excel and making Word documents about our findings.Ī simple Python script running on a Raspberry Pi logs the time and temperature every 5 minutes in a CSV file. Today I logged the temperature in our ICT room as part of a wider Y7 project on data handling, spreadsheets and climate change.