Relevés de température: howto. 2) L'adaptateur 1Wire-RS232 ou 1Wire-USB Il est possible d'utiliser trois types d'adaptateurs pour raccorder ce capteur à l'ordinateur: On peut très facilement construire le type RS-232 passif (voir les instructions pour construire l'adaptateur utilisé pour les mesures de températures). On peut aussi utiliser des adaptateurs disponibles commercialement chez Maxim/Dallas, chez AAG Electronica ou HomeChip (voir les liens ci-dessus).
Il existe un quatrième adaptateur de type RS232 actif amélioré censé donner des performances constantes aussi bien pour des bus 1-Wire courts, longs, ou très longs. Il est disponibles chez AAG Electronica, chez ibuttonlink ou chez HomeChip sous la référence the link. Pour des distances courtes (jusqu'à 15-20 mètres entre le capteur et le serveur), on peut utiliser un adaptateur passif.
Dans tous les cas il est préférable d'utiliser un câble blindé pour le bus 1-Wire, le blindage étant raccordé uniquement du coté de l'ordinateur (à son chassis). Optional Gypsum Block Soil Moisture Protocol. Task A: Installation of gypsum blocks Materials and Tools Field/data book and pencil Five cm soil auger An old screwdriver or kitchen knife to remove soil from auger A meter stick Four gypsum blocks Four 10 cm long x 7.6 cm diameter PVC tube or tin cans for wire holders at the surface Two 4 L soil holding/mixing buckets 1 L water for making mud balls One 1m x 2 cm PVC guide tube Soil packing stick (old broom handle) What to do and How to do it Do not report measurements for a week after installation.
Task B: Reading the Soil Moisture Meter Congratulations! GLOBE Science Notebooks Soil-moisture meter Preparation Test the soil-moisture meter to ensure it is functioning properly according to the manufacturer's instructions. How to Make a Soil Moisture Reading How to use the "Daily Gypsum Block data worksheet": There are numbers 1 to 0 in the far left column. Task C: Calibration of Gypsum Blocks GLOBE Science Notebook Five cm Soil Auger Old screwdriver or kitchen knife Metric ruler Graph paper Calculator Dr. Gypsum Blocks : a type of Soil Water Content Sensors on the sowacs web pages.
How to make a cheap soil moisture sensor – Heavy Duty Version. Best DIY cheap soil moisture sensor 4.4 years ago cheap, electronics, moisture sensor, water My first version of my cheap soil moisture sensor has worked great for me but it did have a couple flaws. The first issue was construction, though I had great luck on my first attempt though after trying to recreate additional sensors given the small amount of gypsum between the sensor and the probes were so thin it was extremely easy to crack the sensor and I normally have about a 25% success rate on later creations (must have had beginners luck on the first one. The second issue was durability. How it works: There were many questions in the comments in the previous post so hopefully I can clear this up a little here.
Technically a gypsum block measures soil water tension. As water is added to the problem more electrons can pass between the probes effectively reducing the amount of resistance between the problem to the point when it is fully saturated where the probe has virtually zero resistance. Soil Moisture Sensor Probes. VH400 Soil Moisture Sensor Probes Soil Moisture Sensor Probe Applications Irrigation and sprinkler systems. Moisture monitoring of bulk foods. Rain and weather monitoring. Environmental monitoring. Water conservation applications. Soil Moisture Sensor Probe Features Extreme low cost with volume pricing.
Other Vegetronix Products of Interest Soil Moisture Sensor Probe Pricing and Ordering Info Contact us for pricing information. Soil Moisture Sensor Relay Boards The quickest way to evaluate if the VH400 series is right for you is to also order some of our sensor relay boards. Soil Moisture Sensor Probe Specifications Soil Moisture Sensor Probe Wiring Table VH400 Soil Moisture Sensor Probe Drawing VH400 Soil Moisture sensor Drawing Soil Moisture Sensor Probe Technical Literature See our Soil Moisture Sensor Probe Application Notes for reference designs and information on how to use the soil moisture probe in larger systems. How to Get Started with the Soil Moisture Sensor Probe. How to make a cheap soil moisture sensor. Soil sensors can be pretty expensive to purchase but a few minutes and a few cents worth materials around your house you can make your own accurate cheap soil moisture sensor.
UPDATE: Though this still a great sensor, check this post for the latest version of a more heavy duty soil moisture sensor. I mentioned in a previous post that my previous soil moisture sensor did not hold up in my automated grow box update, so I needed to make a new one. After a little research there was the classic science class method of creating a homemade sensor by simply putting two galvanized nails in the soil and measuring the resistance between them. A major problem with this solution is the soil composition can significantly vary the resistance and keeping the spacing between the nails could be troublesome. After a little more research I came across the method that has been working well for over 50 years. I straightened out one end of both wall hangers the best I could with some needle nose pliers. Electronics Project - News: Plant Watering Watcher.