Practical Tips and Techniques
The DHT11 is a digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air and sends out a digital signal on the data pin (no analog input pins needed). Its simple to use, and the update timing of the sensor is about 2 seconds. Thermistor temperature … Read more
We will now look at the data logging capability using our Click plus PLC. Data logging is the collection of data over time. This is usually used for data analysis at a later time. The amount of data (System Information) stored and the frequency of the storage will depend on your specific application. The hardware … Read more
We will now look at the connection to our SQL database using a spreadsheet application. Previously we used Node-RED to communicate Modbus TCP and RTU to our Click PLC and Solo Temperature Controller. The information collected from the controllers was then put into an SQLite SQL database. Spreadsheets like Excel are great for analysis of … Read more
The ultrasonic sensor (HC-SR04) is great for all kinds of projects that need distance measurements. The HC-SR04 is inexpensive and easy to use. We will be sending signals directly to the sensor and interpreting the results without the need for a library. Ultrasonic sensor module HC-SR04 provides a 2cm-400cm non-contact measurement function, the accuracy can … Read more
We will now look at the MQTT communication capability using our Click plus PLC. MQTT stands for Message Queuing Telemetry Transport. This simple ‘publish and subscribe’ communication protocol, does not take too many resources. Constrained devices with low bandwidth are ideal for MQTT. This protocol provides machine-to-machine (M2M) connectivity which is ideal for the Internet … Read more
Node-RED can easily log data to a database. SQL (Structured Query Language) can be used to communicate to a SQL database. Databases separate analysis from the data unlike spreadsheets like Excel. The database is designed to hold more information than spreadsheets and allow multiple users to access the information. We will be creating an SQLite … Read more