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We started shipping PIR KumoSensors with firmware that allows sensitivity adjustment today (2015/11/6). When you receive your new PIR sensor (will show as "rev 8F" in search result), you will be able to access the sensitivity slider from the Web interface at

With this new feature, you can reduce sensitivity if you are getting false alarms due to very short movement lasting less than a second. We tested this feature on two customer returned PIR sensors that were prone to produce false alarms. With sensitivity set to 50%, the false alarm completely went away, while each detects normal human movement every time. 

With the next iOS app update (version 2.6.0) you will be able to display temperature, humidity, motion event state or last update time of selected tags on lock screen. You can touch/tap on the colored square to the right to switch the display between humidity, last update time and motion sensor state. 

wireless tag widget ios humidity wireless tag widget ios updated ago wireless tag widget ios motion event

You don't have to launch the Kumostat app or even unlock your phone. Just drag down from the top of the screen to reveal the "Notification Center" where you can click the "Edit" button to add the "Temperature/Humidity/Motion widget". 

The nice thing about this feature is that you can mix&match multiple tags you want to show from different tag managers. Instead of data of all available tags, only data of the chosen tags is downloaded resulting in quick load time. 

In this version, we could not get the automatic display update to work within the widget, i.e. if a tag is moved, it will not automatically be updated in the notification center, unlike it does in the app. The display in the notification center should refresh/update if you hide the notification center and then open it again.  

You can now switch to display humidity as "Dew Point temperature" instead of "Relative Humidity (RH%)" from the Humidity Options screen (open by tapping on the humidity display in the app). This is available currently in Web, Android app version 2.8.16 or above, and the latest iOS app currently under AppStore review.

Relative Humidity is, like its name suggests, a relative measure of water content in the air. It is the ratio of current water content relative to the maximum water that can be dissolved.

Dew Point on the other hand, is like "absolute humidity". It indicates the temperature at which condensation forms, which is only determined by how much water is dissolved in the air currently, and is unrelated to current temperature. Dew Point is a better indicator of how humid the air actually feels.

Because the higher the temperature of the air, more water can be dissolved, if we plot RH% like our app could only do in the past, often you will see it has strong negative correlation with temperature, i.e. it just moves in the opposite direction of the temperature change, and it was hard to tell the actual change of water content in the air, or how humid the air felt.

If you switch to Dew Point display, all of a sudden, the humidity trace is decoupled from temperature change, and the water content change becomes much more clear. We can see from below plot, that as temperature rises new water is dissolved into air (for example there might have been a water puddle before the temperature rise), but the dew point reaches peak before temperature reaches its peak, indicating the water puddle is gone, or drier wind blew the water vapor away.

We occasionally hear from heavy users (who runs almost a hundred tags off a single tag manager at short logging interval) that "spikes" appear in the temperature or humidity graph. While this is sometimes caused by defective temperature sensor IC itself (which resolves by requesting a replacement tag) it may also be caused by bit-error in transmission in a noisy radio channel shared by many tags. By default, each tag uses 8-bit CRC implemented by firmware on top of a 16-bit CRC-CCITT by hardware. This provides an upper bound of undetected error rate of one in 16.8 million regardless of bit error rate of the raw radio channel. However, if each tag transmits once per minute and you have 100 tags, you may encounter an undetected error (which appears as a corrupted temperature data point or a spike in the temperature graph) every 116.5 days. 

To improve this, we have added an option to turn on 32-bit CRC error checking already implemented in the radio hardware.

This reduces the error rate to 1E-12 or one in trillion. Now you should not be getting any bit-error caused spikes in temperature/humidity graph. If after you turn on this option and migrated all tags, and you still have the spikes, contact support and we will email you a prepaid return shipping label to send back the tag for a replacement right away. 

Feb 10, 2016:

You can now edit the temperature or humidity graph by "click to remove point" like below. This will allow you to remove data points that you believe is bogus manually. After you are done, click the yellow "Save" button to permanently delete these data points. 

This feature is currently only available in the web interface on a PC or Mac. Go to then click the blue "Stats" on the bottom of the page and choose either "Temperature" or "Humidity". Zoom into the graph until it shows each raw data point. Then scroll to the bottom of the page to access these buttons. (If you do not see them press F5 key to force your browser to refresh its cached version of the page.)

 We are pleased to announce that all Wireless Tags PRO you buy on or after May 27 will include these exclusive updates:

  • Choosing too hot/too cold temperature monitoring thresholds at 0.02°C step:
    The Wireless Tag PRO uses the same digital temperature and humidity sensor IC as Wireless Tag (with 13-bit temperature/humidity) which has a resolution of 0.02°C (13-bit). However, until now thresholds were stored in 8-bit numbers, so you were only able to set thresholds at ~0.6°C step (the accuracy of the threshold is unchanged with this update). This update is especially powerful when used in conjunction with Nest/Honeywell WiFi thermostats, because you are now able to regulate temperature much more precisely using too hot/too cold events from sensor tags.
  • Programmable sampling-rate for temperature monitoring:
    This allows trading off battery consumption with the response time of the tag to temperature events. Because the tag only transmits readings when the temperature crosses a threshold, not when every time it samples (checks if temperature is too high or too low), setting a fast sampling-rate like every 30 seconds has much less impact on battery life than setting a 30 second auto-update interval.
  • Hardware delayed notification:
    When you are using the tag to monitor temperature inside a fridge or freezer, your purpose is to get notified when the compressor breaks down or exhibit chronic problems. You probably don't want to get notified when temperature increases temporarily because the fridge/freezer door is opened for loading/unloading. "Delayed notification" allows the too-hot or too-cold event to be transmitted only when the sensor reads too-hot or too-cold for a programmable number of times, in a row. A similar feature is available currently in a KumoApp script but it was based on auto-update/logging data points, and drained battery more quickly because a relatively short auto-update interval must be used for it to work. 

New temperature options in Web/Android and iOS (2.4.11+) available with the new Wireless Tag PRO

We are pleased to release an improved Web/Android app (version 2.8+) with a more logically organized, more touch optimized user interface.

In this redesign, our goal was

  • Often used option screens should be easier to open with 1 click, instead of first clicking "Options..." then choose from a long, confusing menu listing choices about unrelated features together. Now temperature/humidity/motion/etc option screen can be opened by clicking on the temperature/humidity/motion/etc display.
  • instead of grouping status display and options of unrelated features together, everything related to one feature, such as "temperature sensor", "motion sensor", "light" should be grouped under its own button. This way if a user does not use a feature, he/she can simply ignore the button for that feature.
  • The buttons should be stress-free to press on smartphones/tablets. Now the button for each feature are closer to square shape just like app icon on home screen.

The end results felt so much better compared with the old Web user interface, we wonder why we did not think of these sooner and let people live with such a confusing interface for so long.

Your comments are welcome!

EDIT (April 21):  Keyboard navigation: You can now use TAB key to jump through each buttons, and press ENTER key to activate button/open menu. When a menu is opened, you can use UP/DOWN ARROW key to choose, and press ENTER key to confirm. or press ESC key to close the menu. When an option screen is open, you can use ALT+LEFT ARROW key to go back / close the option screen without saving.

Now you can link Honeywell WiFi Thermostats (aka Total Connect Comfort) the same way as you can link Nest Thermostats and automate using temperature readings from any chosen Wireless Tag, as well as take advantage of automation algorithms in KumoApps such as "turn off when window is open and resume when closed" or "turn on when any of my phones gets close to home". Web/Android apps currently have this capability, and iOS app 2.4.2 and above will add this capability when it gets released at AppStore. Enjoy!

We understand a lot of you are using Wireless Tags for monitoring temperature and humidity only. As a market experiment to find out if the motion sensing capability is really necessary, we are now offering a version of Wireless Tag Pro with the motion sensor disabled (by firmware) at a reduced price.  

The hardware is identical with regular Wireless Tag Pro, and the disabled motion sensor does not consume any power. To order, choose "1 unit (no motion sensor" or "5 unit (no motion sensor)" from the drop down menu above "Add to cart" button.

We are pleased to announce that now the stats graphs in Non-Android Web interface (i.e. for PC, Mac and other desktop users, Android app of course uses native OpenGL based code) are completely re-written using HighCharts 4.0 (used under commercial license) to rival the quality of graphing in our iOS and Android app. These stats graphs are accessed either from the blue "Stats" button or from "More..." -> "Temperature/Humidity Graph" button. 

Some Live Examples:
You will immediately notice the improved load speed and visualization thanks to the intelligent tool-tip. As you use mouse drag for zooming in and Shift key+mouse drag for panning, raw data point will be dynamically downloaded from server around the displayed region to maximize initial load time even when millions of data points are captured. If more than 60 days of data is displayed, the graph automatically enters a mode that displays the day's high and low temperature/humidity/battery voltage, similar to what the iOS and Android app graph is doing. You can also download the graph as PNG file, in addition to the CSV download capability. 

For motion/door stats, the chart will initially show the number of open or moved event per each hour. As you zoom in, the graph transitions to event type vs. time scatter plot to show the exact time (down to second) of each of the moved, opened, closed, detected or timed out event. 

We have updated the server to optimize the water/moisture level measurement full-scale to allow better resolution, especially at higher % value for more accurate water level measurement.

Until today, the water/moisture sensor has been working fine to measure typical soil moisture for plants, but if you dip it into water to measure water level, the reading becomes well over 100% and the resolution decreases. Applying calibration can move the reading back to 0~100% range, but did not improve the resolution problem. 

With this optimization, without calibration, the sensor would report 0% when sensing surface is completely dry, and 100% when sensing surface is completely submerged into water. And the reading will reflect the actual water level with much greater precision and number of quantization steps than previously. If one intends to use it to measure soil moisture, one may want to re-define 100% using the "Calibrate" button at the maximum wetness possible for the type of soil. 

This optimization automatically takes effect for newly associated water sensors. For existing sensors, please disable moisture monitoring, click save, and re-enable moisture monitoring for this to take effect.

Android app version 2.3.10 and above now supports WeMo LED Light Bulbs with dimming value and fading speed controllable from the UI and KumoApp (using the new dimLED method). Before, only WeMo switches were supported. You can write super low latency automation algorithms using KumoApp such as "when reed sensor detected door open, gradually ramping up the light bulb."

iOS support will be available in AppStore version 2.3.3 (and TestFlight beta internal version 2.3.12).

Since release of iOS 8, AppStore is taking much longer to review and release app updates. We have exciting new version of our iOS app waiting for review for more than 10 days. This version (2.3) contains

  • Many bug fixes, including fixing critical issue that freezes the app when trying to switch between multiple tag managers in iOS 8, and option popover window not showing up / causes app crash on iPads with iOS 8.
  • Ability to link WeMo switches and install KumoApps that automate WeMo using sensor events and data.
  • Styling update
  • Explanation (help text) of what each multiple-choice option does inside the app. 

iOS 8 introduces a new program called "Test Flight" which allows interested iTunes user to install new versions of apps still under review. To join, we just need to add your iTunes account email. If you want to try out our future version iOS app (that often contain critical bug fixes and exciting new features) please send an email to with title "Join Test Flight" and your iTunes account email in the body. The number of users we can add to Test Flight is limited so this will be provided while supply lasts.

UPDATE: Our latest app is already released on AppStore and we no longer need TestFlight to release bug fixes for iOS8 as of now. If you have the app installed from Test Flight, please uninstall it and re-install the latest version from AppStore

We are pleased to announce that Nest Link is now working properly. 

The problem was caused by the obscure "spec" of Firebase which only allowed a single user to authenticate in a given Firebase server even it appears that multiple instances of Firebase clients are created and isolated. Single user operation is a reasonable assumption for a mobile app, but it is definitely not reasonable assumption when Firebase releases a client for node.js which is used to develop a web server. This "spec" was not clearly described in Firebase documentation which caused confusion for other developers too.

So, until today, Nest Link was working only for the last user that used it, because Firebase node.js client only allows one user to be authenticated to a given server at any given time. 

We have scrambled to replace the Firebase node.js client with our own that uses open standard REST streaming, which Nest also supports but with more limitations than with the native Firebase code.  

Now we have confirmed that the Nest Link seems to be working simultaneously for everybody. 

If you have given up on the Nest Link and associated KumoApp algorithms before, we encourage you to give them another try. No special step is needed to make this fix take effect on your side.

You can now link Dropcam to your Wireless Tag account. This will allow you to
    • Take snapshots and save them at the full 720p resolution
    • Turn streaming on and off
    • Do the above from KumoApp recipe. For example, you can write a KumoApp to take a burst of photo (at about 2fps) when PIR Kumo Sensor or Motion Sensor Tag detected movement, or door is open, and then email to you. You can also schedule pictures to be taken at certain interval, or any logical combination you can write using the KumoApp Javascript engine.
      • No more false activity alerts from the less-than-perfect motion detector on your Dropcam!

This is similar to the way you can link Nest Thermostats and WeMo switches. It may seem unnecessary to be able to control them from the Wireless Tags app when WeMo, Nest and Dropcam already have their own mobile apps, but it is when you start to write (or install existing) KumoApps like below, that this will all make sense:

Lastly, if you ever wanted to link Wireless Tag with other stuffs than WeMo, Nest, Dropcam or Philips Hue that can now be done with KumoApp, try our unpublished IFTTT channel. It is currently under review by IFTTT staffs for quality assurance. But many of Wireless Tag enthusiasts have already tried it (even before this article!) and we have already received some good feedback.

Using the latest Android app (version 2.2) and iOS app (version 2.3.1 and above, which should be released in AppStore next week) you can link WeMo switches as a tag to allow automation through KumoApp. These KumoApps have been made available (you can install them or make your own version based on their source code, once you link your WeMo switch):

  • When any of the PIR sensor detected motion, turn on Wemo, when all times out, turn off Wemo
  • When any of the PIR sensor detected motion while all of specified phone are away from home, turn on Wemo (makes potential thieves think you are at home)
  • When more than specified number of PIR sensors detected motion, turn on Wemo, when the number falls below, turn off Wemo
  • When any of the door is opened, turn on Wemo
  • When any motion sensor tag is moved (when they are armed), turn on Wemo
  • When any motion sensor tag is moved (when they are armed), and while all of specified phone are away from home, turn on Wemo
  • When any of specified phones enters region, turn on Wemo switches
  • When temperature is too high, turn on Wemo, when temperature is back to normal, turn off Wemo
  • When temperature is too low, turn on Wemo, when temperature is back to normal, turn off Wemo
  • When all specified phones leave region, turn off Wemo switches

Linking WeMo switch is very similar to linking Nest Thermostat. After you have connected you iOS or Android device to the same local WiFi network your WeMo device is on, launch the WirelessTag app and click the "+ Associate" button. If the app can find a WeMo switch on your local WiFi, a green "Link WeMo" button will show up (you may have to give the app about 10 second after launch for it to find your WeMo devices). Linking WeMo device function is not available from Web Interface on laptops, but once linked, WeMo device can be controlled from the Web Interface as well as from KumoApp. 


UPDATE: With latest version of Android app 2.3.5 we have improved the reliability of the app finding WeMo switches on your network. You need to connect the Android to your local WiFi for the green "Link Wemo" button to show up. The iOS app 2.3.1 is still under AppStore review as some issues were discovered during review and delayed the release. You can join the Test Flight program to try out this iOS app version and any future pre-release versions.

Over the next few months, our priority will be to integrate Wireless Tags with as many Internet connected products and services as we can think of. 

As part of that plan, we are pleased to announce today that we now support OAuth 2 for linking our API. 

Get started

OAuth 2 is used to link 3rd party web services without giving up account login and password to that 3rd party. It is used by everybody from Nest official API to Twitter to Facebook login. 

By supporting OAuth 2, we make it easy for people to develop "apps" that use our API. 

We will be developing one of such apps to integrate us with Zapier very soon. 

The Android app now uses native OpenGL based graphing code to handle large amount of data points (e.g. plotting data from up to 255 tags on the same screen) and to allow smooth zooming/panning by touch gestures. Also the same code for iOS app graphing has been ported to Android for dynamic download of raw data points from cloud as graph is zoomed or panned, so even if millions of data points are captured, the graph will load instantly.

You are able to download the entire data as CSV file using the download button at upper right corner (to email, Google Drive, Drop box etc) or share the displayed graph as PNG file using installed photo sharing apps (Email, facebook, picasa etc) using the share button.  

Install it from Google Play

If you are mainly using the Web interface with mouse (on Mac or PC), you can now drag & drop each tag entry to change the order they are displayed. The sorting you did is automatically remembered by the cloud and be synchronized across devices (e.g. the tag list on the iOS device will appear in the same order).


We have noticed that again there has been more "Operation timed out" errors for app-to-tag communication, like arm/disarm, apply configuration changes or beep. Upon investigation using network packet analysis, we have blocked several IP addresses that were flooding our server with invalid IP packets. Also we have lowered the "ping frequency" of tag managers to reduce the amount of non-essential traffic. As a result, now the latency from app to tag manager is much shorter than before (always <1s and without timeout error) and the majority of app-to-tag communication latency is now from the tag radio receiver delay, which is programmable from Wireless Settings and in trade-off with tag battery life. 

You can test the intrinsic latency from app to tag manager, by using Debug Console (after you login) where you can use the "Get" button to read tag manager register values chosen at the drop down, e.g. AFSKCTRL, RSSI, etc. note the result only appears after 2nd read.)  The delay from clicking "Get" button to the result appearing, equals to the delay of app commands like "beep" minus the actual tag radio receiver delay

UPDATE (Aug 29) We have switched to a completely new IRC server software that uses "Windows I/O Completion Port" to handle large number of connections. These timeout issues seem to be completely gone now. 

KumoApps are supposed to allow defining triggers that use location of iPhones and iPads (, such as "Arm motion sensors when all phones are away from home, disarm when any enters near home." and "Turn off AC/heat when all devices exit a region". However due to bug in the iOS app, this did not really work at all until now.

We are pleased to announce that with the latest iOS app release, these KumoApp will start to work. When you stop and restart the KumoApp, the holder of each device you have chosen will receive a push message that asks for permission to start monitoring region for the KumoApp. The holder would tap on the notification to open the app to start monitoring the region configured with the KumoApp. Once monitoring is started, even if the iOS app is closed, KumoApp will be triggered upon entry and exit of the specified region.

There are still several known issues which will be fixed in the next release:

  • If you receive "error start monitoring region, kCLErrorDomain error 4", you need to go to home screen, open the "Settings" app and then "General" then "Background app refresh" and disable and re-enable the toggle switch next to "Kumostat" app.
  • Sometimes you will receive "error start monitoring region, kCLErrorDomain error 5". This error can be safely ignored.

Try linking your Nest Thermostat and install the "Turn off AC/heat when all devices exit a region" today.

During the past few weeks, user initiated commands like "ping" "beep" "arm" "disarm" resulted in "Operation timed out" error more often than what we consider normal (2~3% of the time). This problem was related to a background process we were running to implement out-range/in-range notification feature. A spike in server issued command to search for out of range tags caused over capacity in one communication channel, resulting "time out" error for regular user commands. We have resolved this issued by controlling the rate such background search command is sent out.  If you still experience "time out" error please report it in the forum or email to