“To gain scientific understanding into the vinification process of Madeira wine, we intend to use sensors to study various parameters of the process (e.g. Ethanol, pH, total acid, volatile acid, density, fixed acidity, ash,), as well as actuators to control the environment (e.g. temperature, humidity, etc.)”
Search for sensors
One practical use case was wine monitoring. Due to our limited knowledge in electronics, we looked towards sensors with easy interfacing, to be able to connect in Arduino. Here is a list of measurable parameters that can be interesting for wine analyses, however, many of these parameters are manually analysed in the lab, using heavy equipment.
After some search, we found some experiences using gas sensors and other sensor, which helped us to make a decision to order or not.
The main criteria for selecting sensor for this experience was :
– easy interfacing
– no maintenance
|Measure in liquid||Order||Use|
|pH||Yes||(+) Seems reasonable|
|Color||No||(-) Expensive(-) Specific HW and SW|
|Dissolved Oxygen||No||(-) Expensive(-) Specific HW and SW(-) Maintenance|
|Volatile acidity||No||(-) No sensor|
|Total acidity||No||(-) No sensor|
|Oxidation||No||(-) No sensor|
|Ethanol||No||(-) Expensive(-) Specific HW and SW(-) Maintenance|
|SO2||No||(-) No sensor|
|Measure in gas||Order||Use|
|CO||No||(+) Reasonable(-) Less important in wine|
|Relative Humidity||Yes||(+) Reasonable|
pH – pH probe from Vernier
Temperature – Temperature sensor with steel head, from Seeed Depot
CO2 – Parallax CO2 module with mg811 c02 gas sensor, from Parallax
Alcohol – MQ3 gas sensor, from SparkFun
RH – Relative Humidity sensor, from SparkFun
After the arrive of ordered sensors, we started to test them.
The probe construction was the most difficult part to do, because of excess of wiring and lack of space inside the probe. Three attempts were made to build a stable probe (float with equilibrium in the wine), but it was very difficulty to wire and use all sensors along with pH probe in the same module. And in the end the probe was not floating :'(.
Building probe with success
After the previous experience we came with a more simple solution, use 2 modules, one for pH and temperature, and the other for gas sensors, the last attached to the top of the wine container. The upper module has 2 separated parts, the top one contains the micro-controller (Arduino) , DC jack and RF transmitter an receiver. The bottom part contains the c02, alcohol and relative humidity sensors.
We have the probe uploading sensor data every minute, (RF 433MHz module). The sensor gateway (Arduino + ethernet shield + RF receiver module), receives this information and sends via HTTP POST to server, which then is published using XMPP protocol.