Introduction: Industrial IoT Applications - External Sensors + Charging W/ Android USB Aka Micro USB Host OTG Y-Cable W/ Power

About: I love remotely monitoring Industrial IoT / IIoT sensors. My favorite things is water monitoring systems, water levels / well telemetry, and flood warning systems. Questions? Please don't hesitate to get in t…

**Update: The article below is from our legacy Android app! Valarm is Industrial IoT. The bottom line is that we'll help you, your teams, and your business organization with Industrial IoT and remote monitoring applications using

We recommend using dedicated sensors hubs (e.g., GSM cell network or WiFi) with any sensors since they're much more reliable than Android telephones for your Industrial IoT monitoring applicationslike:

You can use Valarm Industrial IoT, telemetry and remote sensor monitoring solutions with any of the following connector devices: receives your organization's GPS-tagged, time-stamped sensor information via any internet connectivity like WiFi, ethernet, or cell network.

On you've got services for mapping, graphing, 3D analysis, and APIs like JSON to help you with your real-time, geo-enabled sensor monitoring and Industrial IoT applications.

Your Industrial IoT sensors and remote monitoring hardware are available at is an open platform so you can use made by any sensor hardware manufacturer. Here are some favorites our customers deploy and remotely monitor with is an open platform so you can use sensors made by any hardware manufacturer. You’ll want the most rugged and reliable sensor for your specific remote monitoring needs. Our industrial customers have some favorite sensor brands like:

Whether you need mobile or stationary monitoring systems, let us know what you, your teams, and your organization need to monitor. We’ll work with you to deploy your most effective monitoring systems to improve your business operations.

Have a look at our Customer Storiespage to see how Industrial IoT sensors are used for remote monitoring in all industries.

How does remote monitoring help you, your teams, and your organization? See how remote monitoring improves your business operations, saving you time and money with Web Dashboards.

Please don’t hesitate to contact us at Info@Valarm.netif you've got any questions.


How do you charge a phone or tablet while running the Valarm Pro app with external USB sensors? This instructable from Team Valarm shows you how!

Why did we solve this problem? Valarm provides sensor and monitoring solutions that facilitate rapid deployment of real-time, ad-hoc, mobile sensor networks for remote environmental monitoring, mobile data acquisition, and asset / vehicle tracking. Valarm connects industry-standard sensors, makes them location-aware, and streams their data to the cloud or to private networks, using readily available commodity hardware. To do all of this our customers in over 30 countries around the world use these USB OTG + Charge Y cables to monitor anything, anywhere!

Some tablets (especially 10″ models) are equipped with a dedicated power jack. But most tablets (and all phones) charge via the same USB port that will be hosting your external sensors. A simple OTG+Power “Y-cable” is the solution. Below is a video demonstrating the Charging + OTG Y-cable being used to plug a phone into a USB sensor at the same time it is charging.

Where do you get one of these fancy Y-cables? The specification varies between manufacturers, but if you have a Samsung or Sony device, you are in luck!

Micro USB OTG Y-cables for the Samsung devices (e.g., Galaxy S3 and S4) are available in the Valarm store.

Want to build your own? You can make your own cable for a Sony device (e.g., Xperia U ST25) by following the instructions below or else you can buy a factory-made cable from us.

Micro USB OTG Y-cables for the Sony devices (e.g., Xperia U, SP, Z) are available in the Valarm store.

To build your own you’ll need a few tools and supplies:

- USB cables with Micro USB and full size USB ends
- Soldering iron and solder
- Wire cutters
- Wire strippers
- Dremel or something else to cut and expose a USB cable’s circuit board
- Resistor (To make a Sony compatible USB OTG+Charging Y cable use a 100K Ohm resistor. To make a Samsung compatible USB OTG+Charge Y cable use a 64.9K Ohm resistor (available here)

Step 1: Remove Cover From USB Male Plug

First cut off the head of a micro USB male plug and strip the plastic (we used a Dremel and wire cutters) to expose the circuit board.

Step 2: Solder 100K Resistor

Next solder one end of your 100K Ohm resistor to pin 4 (a.k.a. sense pin). To make a Sony compatible USB OTG+Charging Y cable use a 100K resistor. To make a Samsung compatible USB OTG+Charging Y cable use a 64.9K resistor (available here). The other end will connect to the pad labeled B (which is pin 5/ground).

Step 3: Strip USB Wires

Strip your USB cables with wire strippers to expose the 4 USB wires: red, green, black, and white here from a Samsung cable (other cable brands may use different colors!). One end will plug into your sensor (Micro USB male) and one into your power supply (Full or Micro USB Male or Female).

Step 4: Hot Glue and Heat Shrink

Cover this up with hot glue and/or heat-shrink tubing, and this end goes into the phone. The resistor signals to the phone that it should be a USB host, AND also draw power from the USB port. Now you can solder on your USB cable (e.g., male micro) that attaches to your sensor (solder the red, green, black, and white ends to their corresponding pads) and your USB cable (e.g., male full size) that plugs into your power source (solder only the red and black wires for this connection).

Step 5: Plug in Your USB Sensors (CO2, Thermocouple, IAQ, VOCs, Humidity)

All done: plug your sensors and charger into your device using the Y-cable you just made! For the cable in this picture we used a Mini USB connector to go from the device to a USB hub then all of the sensors (CO2, thermocouple, indoor air quality [iAQ, VOCs] in this picture) can be plugged into Valarm Pro at the same time!

Step 6: Factory Made Cables Available


1) You don’t feel comfortable doing any of the steps above (we’ve done it a few times and admit it can be a bit tricky and time consuming)

2) You would not like to take the time (you do get better at it after you’ve done a few but it still takes us almost an hour to do one by hand)


3) Don’t have the equipment to build one…

You can buy one of Valarm’s USB OTG charge cables in the Valarm store. Thank you for your support!

Step 7: USB OTG + Charging Y Cables for Sony Xperia

The cables are compatible with Sony Xperia phones and we have tested extensively with the Sony Xperia U ST25a and ST25i phones, which are the most inexpensive devices we have found that support USB Host and OTG. You can use the cable to charge an Xperia device at the same time as using your sensors, keyboard, mouse, game controllers, any other USB accessory. Many thanks to Przemyslaw Tracz (a.k.a. sonic_boom) for his website detailing how to do this!

This picture shows Valarm Pro running on a Sony Xperia U ST25i for remote monitoring with an air quality (volatile organic compounds, VOC) sensor and charging at the same time.

Step 8: Remote Environmental Monitoring, Fleet / Asset Tracking, Mobile Data Acquisition With Valarm

These cables are one of the keys to using Valarm for remote environmental monitoring.

We use these cables and solar panel power in Valarm deployments such as the La Brea Tar Pits, Los Angeles Natural History Museum, and vineyards / agriculture. You can use these Y cables with any combination of sensors to do things like air quality monitoring or anything else you want.

Questions about remote monitoring and Industrial IoT?

Talk to me at

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