Technical Specifications

Watchman is a WiFi-enabled indoor device and reads logs every minutes. Logs are sent to pp-Code portal every hour unless there is sudden change in the temperature (+/-5F) due fire/freeze/else (and log is sent immediately): 


  • Temperature -40 to 170F, accuracy of +/-5% 
  • Humidity 0 to 100%
  • WiFi: 802.11 b/g/n, 2.4GHz, support WPA/WPA2
  • Input Power: 110-240V AC
  • Approximate bandwidth consumption is 4KB (for unit running at default hourly log)  or 15KB (for unit running at 15min log) per day.

If you plan to run the unit on a power bank,  we suggest to budget for:  

  • 150mA for regular units 
  • 200mA for units with 1M probe
  • 300mA for  all other unit type.

Thanks to one of our customers (Mark Smith), his team performed power consumption testing (on regular unit) and shared their results: 

  • Startup.peak current 125mA at 5.3v 
  • With LCD panel on steady state low of ~70mA 
  • With LCD panel off steady state low of ~40mA 
    • When contact made to internet, 80+mA
  • When LCD on again initially 100+mA 
    • Settles down to ~70mA

Watchman latest firmware

We are constantly improving. And we would like to give option to our existing customers to benefit from the latest features (with out having to re-buy).

Watchman's latest firmware is version 14. Unfortunately, there is no option to remotely push the firmware to units. If you would like your Watchman unit to be upgraded to the latest firmware, you will need to ship your unit to us and cover the cost:

  •  for return shipping ($4.95 per unit) 
  • and $5 upgrade fee (waived for subscribed customers)

If you are computer savvy, we can send you the files and the instructions. And you should be able to perform the upgrade at your own (and at your risk). Contact us at and we will send you details.

Watchman v15 release notes:

  • Added the ability to show Real Time Reading from anywhere (requires port forwarding, click here for details)

Watchman v14 release notes:

  • Added the ability to turn OFF display light
  • Introduced "WiFi-Rotation" feature (available with paid-subscription). It is useful for WiFi migration or preparing Watchman for a remote site.  

Watchman V13 release notes:

  • Added the calibrate option for humidity 
  • Added "remote restart" ability
  • Added support for json payload on API calls
  • Enhancement product durability for known software bugs

Plugins and Scripts - by community

Hubitat Driver

By Peter Gitta (adapted from the original 'Shelly1 switch' code by Scott Grayban ):

Please find the driver and info here. Also posted at Hubitat community form.

Homebridge Plugin

By Alex Ford:

For those  interested in using Watchman with HomeKit and are using homebridge, the plugin is available at:

BASH (Linux) script to retrieve temperature and humidity readings

By John Beale

BASH (Linux) script to retrieve temperature and humidity readings every minute directly from the unit on LAN:

Frequently Asked Questions (FAQ)

Question: How to reset the unit to factory default?

Answer: Restart (i.e. unplug and plug it back) your Watchman. Then using a tablet/mobile, connect to ppC_noInternet_xxxxxx network, under WiFi settings. Go to web browser (Chrome/Safari is preferred) and type in URL field and hit enter. 

Question: How do I change WiFi settings of the unit ?

Answer: Simply re-perform the setup. The new WiFi information will overwrite the old ones. 

And you do not need to reset the unit to factory default to change WiFi settings.

 1) Restart your Watchman  (i.e. unplug, wait for 10 second plug back)

2) If you have an Android phone, please use our App "Watchman Online" and click on "Setup". Otherwise proceed as following:

Using a tablet/mobile connect to ppC_noInternet_xxxxxx network, under WiFi settings [PC might not let you connect to this network]

(we recommend “Forget” your WiFi network)

2a) Go to web browser (Chrome/Safari is preferred) and type in URL field and hit enter. If page does NOT show up, please check if your tablet/mobile is still connected with ppC_noInternet_xxxxxx SSID (you might need to “Forget” your WiFi network, if you have not) 

2b) Input SSID (i.e. your WiFi network name) and password (of your WiFi network) and press “Connect”  (wait for 10sec – please be patient with it)

2c) As you see “success” message – you are all set (kit will auto-restart in a minute). 

Question: What do I need to do if I take my Watchman to a different location?

Answer: You will need to connect your Watchman with new locations' WiFi (same steps as listed above). You do NOT need to re-register / re-activate your unit on the portal. If you prefer, you may change the name of the location (on the portal) by going to "Locations" page and edit by using the pencil icon.  

Question: I am using WiFi extender. Will Watchman connect to it?

Answer: It may or may not connect to WiFi extender (based on the extender make and model). 

If your WiFi extender has same WiFi credentials as your WiFi router/gateway, we suggest to bring Watchman near to your WiFi router and connect to its WiFi. Once done, you may unplug it and plug it at your desired location (where you are running WiFi extender). Since WiFi credentials are same, your Watchman will auto-connect with WiFi extender.

Please note that Watchman does not support 5GHz  (you need 2.4GHz WiFi signal).    

Question: How do I run external probe into my freezer?

Answer: There are multiple ways, however, one option is to leverage water drain hose if exists. Please click here for an example. 

Question: Is registration on pp-Code portal a must to use Watchman?

Answer: No, it is not. You can directly access your Watchman logs (using API calls) either locally or remotely (requires port forwarding).

Question: What type of information is required for registration?

Answer: Registration only requires a valid email address (so that proper email alerts can be set up). Telephone/mobile number is optional unless you opt-in to receive SMS alerts.

Question: What information is gathered during Watchman activation?

Answer: Watchman unit is mapped to a location. In order to display the logs in location's time zone, you will provide nearest city name to allow pp-Code portal determine the time zone of your Watchman's location. 

You will also name the location such as: basement, bedroom 1, shed, server room 10 etc. Input field is google-map assisted in case you want to use the address as name of the location. Please note it is not a requirement to use the address. You may choose to simply name it or use partial address. As long as it is uniquely named, it works.  

Question: I just activated my Watchman and I only see 1 or 0 in the log page. Where are my actual logs?

Answer: System sends 1st log (1 and 0s) just after a Watchman is activated. Your actual (location) logs will appear with in 15min to an hour.

Question: What type of communication Watchman does on the network?

Answer: Watchman, once connected to your WiFi, has the following external communications:

- HTTP calls to pp-Code portal to send the location's data that Watchman collects. So that it is available on your log page. It works like a browser, similar to Chrome/Safari on your other devices (e.g. tablet, laptop etc). It only sends the data that it collects which is: temperature, humidity, gas level (if your unit has it) and count of active-devices (if Party-Detect feature is enabled) 

- Syslog message (Watchman unit health and event logs) to our syslog server. 

- Message to NTP clock server (on the internet) to clock itself.

Watchman does not perform any internal communication unless you have enabled Party-Detect feature. In this case, it sends "ping" to connected devices on the LAN (to help determine the number of active devices).

Question: We have a firewall on the premises. What ports that needs to be opened for Watchman to operate?

Answer: Please ensure that UDP 123 (for NTP), UDP 514 (for syslogs) and TCP 80 (for HTTP) are open.  In addition, if there is a captive portal / splash page (that requires users to accept terms or provide a PIN before letting them access the network), you will need to white-list Watchman on your internet gateway. It can be done using Watchman's MAC address. Watchman ID (on the back) has subset of its MAC address. This will help you identify it from all MAC IDs visible at your internet gateway. 

Still has questions?

We encourage you to drop us an email at: We are very prompt and most emails are answered with in one business day.

You may also want to check our amazon listing's questions & answers:


pp-Code portal allows you to configure email alerts on the above stats. You can also enable unlimited SMS alerts with paid subscription. The alerts can be very useful for the owners, in cases such as:

  • The cooling/heating system is left running at high while property is not in use (i.e. alert when temperature exceeds/drops a defined threshold)
  • There is a sudden increase in temperature (possible due to fire or else). Though the Watchman kit logs the stats every hour, the kit reads the temperature every minute. In case of sudden increase in temperature (+5F), it immediately sends the log to pp-Code portal (does not wait for the next hour). Owner will receive the instant alert (if it exceeds the configured threshold). Note: kits with version 9 or higher also support sending an immediate log when temperature drops more than 5F.
  • Heating system has failed and may cause pipes to freeze
  • An unauthorized party is being hosted (i.e. alert when people count exceeds a defined threshold)
  • In brief, your Watchman kit could potentioally avoid a disaster and/or save your energy bills. A week-long data is retained on pp-Code portal for your review.
  • There are numerous use-cases for the watchman kit. For example, you are renting your property to vacationers and would like to determine if an unauthorized party is being hosted or heating/cooling system is running high (while property is vacant) - the stats from your watchman kit will be very useful for you. You could potentially save on damage/energy costs.    
  • If you have your goods in a storage area and you would like to ensure that they are stored at proper temperate and humidity levels, you will find this watchman kit very helpful.   
  • Or you want to have environment stats monitored on your home/office (especially when not there) and be alerted appropriately.       
  • For kit to operate, it needs to be connected to WiFi at your location. Please follow set up instructions.


Here is how alerts are implemented:

  • For a given event, such as temperature rising above the configured threshold, a maximum of two alerts will be sent during a 24-hours period. If subsequent logs are still outside of the threshold, no more alerts will be generated. This indicates that the threshold needs to be re-adjusted.
  • On the arrival of a log, which is within normal readings, it resets and re-enables alerting on this event.
  • The above behavior is a on a per-event basis. For example, if two alerts have already been sent on the rising temperature log, the watchman will not stop alerting for other events such as temperature drop or humidity increase etc.
  • If there is a sudden temperature change (+/- 5°F) or sudden gas level increase (+25), alerts will still continue to be triggered (they are not suppressed due to the above implementation). 

About Party-Detect feature

Our innovative Party-Detect feature is an algorithmic-estimate based on active devices on your network. On hourly basis, Watchman determines the number of active network devices. This number gets reset every hour and increases (as the hour proceeds) on detecting active devices on your network. 


The number is sent (at the end of hourly cycle) to pp-Code portal. This number is then processed by our innovative Party-Detect algorithm to "estimate" the number of people at the location. 

The result may not show the exact count (number of people at the location), however it can reliably detect if there is a gathering (or sudden increase in the count) - hence referred as "Party-Detect" feature.

Please note that this feature is offered as a value-add (there is no additional charge) and may or may not work for your specific use-case. We highly welcome your feedback to improve our estimation algorithm. 

The feature is disabled by-default.  

Supported APIs (GET calls) for Watchman

API output in json format (version 13 or higher)

Go to a browser and type in: http://<IP address>/<key>&Stats/json

Or use a API client:

 GET /aa7777063116&Stats/json   HTTP/1.1  (request)


{ "API": {"Version":"1"}, "Stats": { "Temp":"77.9F", "Humi":"66.1%", "ActDev":"1" } }

Read the current stats (V9.1 or higher)

 Go to a browser and type in : http://<IP address>/<key>&Stats

 Or use a API client: 

  GET /aa7777063116&Stats   HTTP/1.1  (request)


  Temp:87.44F Humi:48.3% ActDev:0 (response)

Read the current temperature reading (v9 or lower):

http://<IP address>/<key>&Temperature

Here is an example:

  GET /aa7777063116&Temperature   HTTP/1.1  (request)


  87.44F (response)

Read the current humidity reading (v9 or lower):

http://<IP address>/<key>&Humidity

Here is an example:

   GET /aa7777063116&Humidity HTTP/1.1    (request)


   36.4% (response)

Read the current number of Active Devices (on your local WiFi) (v9 or lower):

http://<IP address>/<key>&ActiveDevices

Watchman’s Part-Detect feature is an algorithmic estimate derived from number-of-ActiveDevices on your local WiFi. The above API call will provide you the current number that watchman sees on the WiFi. The number count is recycled every hour (cycles starts with 1 to the actual count by the end of the hour). 

Requires Party-Detect feature to be enabled (default is: Disabled)  

Here is an example:

   GET /aa7777063116&ActiveDevices HTTP/1.1   (request)


   5 (response) 


   Party-Detect feature is not enabled (response)


  • IP address: local ip address of your Watchman. You can find it by clicking on "Real Time Reading" on our "Watchman Online" App. Alternatively, you can look for it on your WiFi router (Watchman will be shown as "NODE-xxxx"). Since IP is DHCP-assigned, it may change every time Watchman restarts. You may want to statically-assign it on your WiFi router, so that DHCP always assigns the same IP to your Watchman. If you are sending the call over internet (requires port forwarding on your router), it would then be: <router WAN address>:port. The port number is 80.
  • Key: 12-digit specific to your purchased product. Please look for "ID" on back side of your Watchman.

Real Time Reading

Watchman sends a log every hour (can be changed to 15-min interval with subscription). Watchman reads every minute and does react to any sudden change. If temperature changes +/-5F, then it does not wait for next log cycle. It sends the log right away. With this behavior, logs do provide you a very good idea of current readings. 

That said, if you do want to query on demand, Real Time Reading provides an option to fetch the logs directly from your Watchman. It uses the same API call explained in section above. 

This feature is for advanced users who are familiar with port forwarding on their WiFi router / access point.  Please consult your router's instruction manual for detail on how to enable port forwarding.

  • In most routers, you will see an option to configure port forwarding on landing page (after you login to your router). If you do not see it, please check with in "Advanced" menu. You will select your Watchman (will be shown as "NODE-xxxxxx") and port to forward (HTTP-80 is default) . 

If Real Time Reading fails, despite enabling port forwarding,  restart your Watchman and retry after 5min.  

Please note the excessive fetching of logs (e.g. clicking on Real Time Reading button few times with in a min) may make your Watchman to restart. Watchman does a read every minute, hence there is no point in trying to read the data every 2-3 second.