This extremely popular $49 SDI-12 USB adapter is the easiest way to add SDI-12 sensors to a raspberry pi or a PC running windows, Linux, Mac OSX. Similar products on the market sell for a lot more with less features. This adapter essentially allows you to send SDI-12 commands directly to your sensors and read back their responses. You may decide to run the free and open-source data logger code I provide and maintain, or develop your own code. The adapter has been tested for long-term deployment for about 6-month of continual logging.

Here is my 2021 video playlist with introductions and detailed setup guidance:

To integrate SDI-12 sensor on your Arduino instead of on PC, Raspberry Pi, or Beagle Bone Black, check out my SDI-12 data logging shield and dongle:

http://www.inmojo.com/store/liudr-arduino-and-physics-gadgets/item/sdi-12-serial-logger-shield/

SDI-12 sensors are widely used in environmental monitoring including soil, streams, plants etc. On the other hand, data loggers designed for SDI-12 sensors are usually expensive and proprietary, making it harder to monitor and study soils and streams on a budget. This SDI-12 USB adapter makes it possible to directly interface SDI-12 sensors with a PC running Windows, Mac, Linux, Raspberry Pi, or Beagle Bone Black, on a budget. I have built numerous SDI-12 sensor data loggers. This is my latest design that is very easy to use. All you need is the adapter and a PC/Raspberry Pi/Beagle Bone BlackCS215 Air Temperature and Relative Humidity Sensors (Thank Lee!). It also comes with free data logger program (Python script) for all the above operating systems. A section on SDI-12 sensors will guide you through it. FYI, a $150 windows 10 netbook running on Intel ATOM Z3000 series or faster is more than enough to log data. All of the examples in this manual came from one such netbook. A first-generation Raspberry Pi is more than enough for data logging.

Data logging with a Beagle Bone Black

Introduction to the adapter

Live data stream

SDI-12 sensors tested

In theory, all SDI-12 sensors should work with my adapter. In practice, not all sensors were made equal. So far, I have been able to test the following sensors with the adapter, with some help from users like you. There has not been reports of any SDI-12 sensors that are incompatible. The following is a list:

2023-11 list

List of sensor vendors:

• Acclima
• Apogee
• Aquacheck
• Campbell Scientific
• Decagon
• Ecotech (Stevens Water)
• EnviroPro
• FTS inc.
• Gill Instruments:
• Greenshield:
• Hongyuv:
• HSTI:
• METER grou
• Ponsel
• Sentek
• Sutron
• Unidata

The adapter has been designed for long-term data logging, not just hours, days, or weeks, months at a time. The data logging software can also run without problems for months. You can sit back and watch the Python data collection script collect data automatically. My Python script is free and open source and has the following features.

• Automatically names files with start date such as 20160426.CSV
• Uploads data to a server so you can remotely access you data, or plot them with Google Charts (Python logger code)
• A free web page is provided so you can start making your own remote dashboard for your logger (Python logger code)
• Select sensor address
• Enter total data points
• Enter delay between data points
• Select GMT or Local time zone for time stamp stored in local log file

Data logger running on a Raspberry PI 2 B

 Plot from data uploaded to ThingSpeak.com

Web page dashboard for my sample data logger (use it for free)

Just run the python data logger script in Tera Term. Your data will be stored where this script is so if you store the script in a cloud drive, you will be able to view your data remotely. Otherwise, use the data server to store your data and retrieve them.

5-month dielectric constant and temperature

Data file for the 5-month dielectric constant and temperature

Local data log file Format

Your data will be stored in comma-separated-value (.CSV) format. The file name is the date and time when the script starts logging data. There are at least three columns. The first column is the date and time the data point is collected. Depending on your choice, it is either in GMT/UTC or local time. The next column is the sensor address. The third column is the first value returned by your sensor. If your sensor returns more than one value, additional columns will contain additional values.

This file format is ready to be read by any major data analysis tools such as Excel, Open Office Calc, or the more expensive Origin Pro. Here is a sample of data collected from a Decagon 5TM soil temperature and moisture sensor. The first data column is the relative dielectric constant (1 for air, yes, it’s NOT in soil). The second data column is temperature.

2015/10/31 18:30:59, 1, +1.04, +25.0

2015/10/31 18:31:27, 1, +1.04, +24.9

2015/10/31 18:31:56, 1, +1.04, +24.9

This hardware is for sale in several online stores. I ship all over the world from USA. The following are ways you can make your purchase.

Square online store:

• Square online store powered by Square. Square-brand registers are widespread among small retail businesses. You can read more about square here: https://squareup.com/us/en It’s easy to use and provides integrated postage purchasing features. You don’t need any account to make purchases. They accept credit card, Google Pay, PayPal etc. The processing fee is comparable to Paypal. I recommend using my Square online store.

Over the phone/email:

• I can process your credit card directly via my square register. My personal email zliudr@gmail.com still works but all new requests should go to my new email liudrelectronicsolutionsllc@gmail.com. Square-brand registers are widespread among small retail businesses. You can read more about square here: https://squareup.com/us/en

PayPal Invoice:

• I can send you Paypal invoices if you email me the items, quantities, and your shipping address with preferred shipping method, First class or Priority. Email me at liudrelectronicsolutionsllc@gmail.com

Tindie market place:

• Tindie market place has many things I sell and provides different buying options. I have been selling on tindie for a few years. It is geared towards makers and online businesses. Although PayPal processes your payment, you don’t need a PayPal account to make a purchase. Tindie charges a hefty transaction on top of PayPal processing fee so if you’re somehow unable to use other purchasing methods, you can use this market place. It doesn’t have a postage purchase integration so I have to copy your shipping information to another site to purchase postage.

• This version is relatively sophisticated. I recommend you to start with the simple sensor detection and reading and then try the version 1.5.0 or 1.5.7 (below) before trying this first.
• If you have used version 1.5.0, please read the changes notes in the link below. There has been significant changes since 1.5.0.
• This is a back-ported (BP) version, which means it is essentially 1.6.0 but has one feature update taken from my most recent experimental version (not released). This feature makes the script properly recognize onboard serial ports usually on desktop computers so it won’t throw an error when it is running on a desktop PC with onboard serial ports.
• This version has incorporated a lot of new features so it’s best if you run 1.5.0 if you are just starting unless you need the following features.
• Multiple adapters on the same computer/raspberry pi
• Multiple sensing commands per sensor, such as M!, M1!, M2! etc.
• Serial ports are opened by unique ID instead of device name such as COM3 or /dev/ttyUSB0 to make sure always the correct port is opened
• Updates to make the script more stable.
• … Read the changes below.

Changes in V1.6.0