This is a brief follow up post on the WiSense WTM-4P-110 sensor node designed specifically for wirelessly monitoring the temperature of the cocoa bean fermentation process.
Here is some data from a customer site showing the temperature profile during the fermentation process. The data is from April 30 to May 4 (5 days).
The temperature data shown above is from one of the four sensor probes on the wireless node.
The graph below is showing data from all four sensor probes (inserted in to the same fermentation box).
The graph below is showing the battery voltage over the same period of 5 days. The node is powered by 2 AA batteries. The variation is less than .05 volts even though this node was sending data of all four sensor probes every 1 minute.
See below, a typical fermentation box.
For more information on WiSense products, please visit wisense.in.
Here are some pics of the latest version of our Low Power Wireless Mesh Network (LPWMN) gateway with ModBus Interface.
Sub-GHz Radio Options
|Non Certified||Any||Any available ISM Band|
For more information on WiSense products, please visit wisense.in
Our latest product enables Cocoa processors to monitor in real time the temperature of Cocoa beans during the fermentation process.
|Controller||Ultra low power 16 bit Microcontroller (TI MSP430G2955)||Can be upgraded to MSP430F419A or any other variant.|
|Radio||Sub-GHz ISM Band Low Power Radio|
❏ India: 865 to 867 MHz
❏ EU: 868 – 870 MHz
❏ USA: 902 – 928 MHz
> Multiple raw baud rates supported such as 1.2 kbps, 10 kbps, 20 kbps, 38.4 kbps, 100 kbps
> Modulation: 2FSK / GFSK
> Tx Power: Max 13 dBm
> Note that supported baud rates, modulation, bandwidth, duty cycle and max transmit power are subject to local ISM band regulations (ETSI / FCC / WPC etc)
|Certified (FCC/ETSI) and non-certified radio module options available.|
|Antenna||Omni Directional Half Wave Dipole External Antenna |
Gain: +3 dBi gain
|PCB Antenna / Internal stick-on Antenna with U.Fl connector or any other suitable Antenna.|
|Power Supply||2 x AA batteries||Other options available|
> 2 x AAA
|Enclosure||ABS||Changeable on request|
|Temperature Sensor||> Sensor Count: Min 1, Max 4 |
> ±0.5°C Accuracy from -10°C to +85°C
> Overall Range: -55°C to +125°C
> Probe Length: 200 mm (Can be made shorter or longer)
|Changeable on request|
|On/Off Switch||Mounted on the enclosure||Changeable on request|
|Sleep Mode Power Consumption||< 2 Microamps|
|Reporting Interval||From every 1 second to once a day.||Configurable (any time) from the cloud|
|Sensor Node Identifier||Unique IEEE assigned 64-bit address hardwired in onboard EEPROM|
Ex: fc:c2:3d:0x00:00:11:0a:1e (all Hex)
|Temperature Data Reporting Options|
|1||Reports measured temperature periodically with a configurable interval – Minimum (1 sec) / Maximum (1 day).|
|2||Reports measured temperature only when it changes by a configurable percentage value with respect to the prior value reported. Also, reports measured temperature if no report sent for a configurable period of time.|
|3||Reports measured temperature only when it crosses a configurable high or low threshold value. High and low hysteresis values are also configurable. Also, reports measured temperature if no report sent for a configurable period of time.|
|4||WiSense can implement any custom temperature reporting algorithm.|
|Each sensor data message sent by a sensor node to the cloud (via a WiSense Gateway) conveys the information listed here –|
|1||IEEE assigned 64 bit permanent address of the node (Ex: 0xfc:0xc2:0x3d:0x00:0x00:0x1e:0xf5)|
|2||Battery Voltage (Milli-Volts)|
|3||Sensor Probe #1 Id: 0x6c Temperature: Measured Value (milli-deg C)|
|4||Sensor Probe #2 Id: 0x96 Temperature: Measured Value (milli-deg C)|
|5||Sensor Probe #3 Id: 0x97 Temperature: Measured Value (milli-deg C)|
|6||Sensor Probe #4 Id: 0x98 Temperature: Measured Value (milli-deg C)|
For more information on WiSense products, please visit wisense.in.
The graph above shows the ambient temperature measured by seven thermistors on a single sensor egg. Note that the temperature readings are very close to each other as should be because they are all close to each other and measuring the ambient temperature.
The data for this graph was downloaded from the WiSense cloud resident data collection and visualization platform.
The setup has one sensor egg (with seven thermistors) sending data to the cloud (via a WiSense gateway) periodically every 30 seconds. Total of 2880 sensor data messages were sent over a period of 24 hours. Each sensor data message also conveys the voltage of the Li-Ion battery inside the sensor egg.
For information on WiSense products, please visit wisense.in.
We are now offering sensor nodes with extruded aluminium enclosure.
Enclosure material is anodized extruded Aluminum
Anodizing is an electrochemical process that converts the metal surface into a durable, corrosion-resistant, anodic oxide finish (anodizing.org).
Extrusion is defined as the process of shaping material, such as aluminum, by forcing it to flow through a shaped opening in a die. Extruded material emerges as an elongated piece with the same profile as the die opening (bonnellaluminum.com).
Pics below show a wireless temperature sensor with an external probe. The extruded aluminium enclosure shown is 94mm x 83mm x 30mm in size. The two end-plates have 4 screws each. We have drilled holes in the end plates for the panel mount U.Fl to SMA RF cable assembly and two LEDs. The opposite end plate has a hole for the sensor cable. This enclosure is not IP rated.
Since the material is a metal, this enclosure is not suitable for applications requiring an internal antenna.
For information on WiSense products, please visit wisense.in
The WiSense IoT dashboard offers real-time sensor data collection and visualization on the cloud. The dashboard has a powerful relational database storage with fast response time for UI data updates. The UI comes with various visualization options and also supports configurable SMS/Email alarm generation features.
WiSense builds and maintains this dashboard for our customers. Our customers can use it even when they are not using WiSense hardware.
The dashboard can run in the cloud or locally within customer premises.
The snapshots below show a simple dashboard built for a customer’s factory having five WiSense WXI-RH/T-10 wireless sensor nodes sending relative humidity and temperature data to the cloud.
The customer has a (WiSense provided) login id and password to access this data.
The snapshot below shows the visualization screen which can show both real time and historic data. This particular snapshot is showing temperature (T) and relative humidity (RH) data stream from a WiSense WXI-RH/T-10 wireless sensor node installed in chamber 01.
The snapshot below shows the last received sensor data and associated time stamp from the sensor node in chamber-01. In addition, this screen allows the generation of e-mail/SMS alerts through configuration of sensor data thresholds for each sensor data stream.
I will take the relative humidity (RH) data to illustrate the threshold settings. The snapshot shows the upper threshold set to 80 %, the lower threshold set to 40 % and a hysteresis value of 2.5 %. The corresponding chamber will enter an alarm condition when –
- RH rises above 80 %
- Here the chamber enters the alarm condition “RH above upper threshold”
- RH falls below 40 %
- Here the chamber enters the alarm condition “RH below lower threshold”
The chamber is not in any alarm condition as long as the RH value is between 40 % and 80 %.
The hysteresis value of 2.5 % prevents unnecessary alerts (e-mail/SMS) from being generated in case the RH value fluctuates around the threshold value. It is up to the customer to choose the appropriate threshold and associated hysteresis value.
The dashboard will send out a e-mail and/or SMS to configured recipients if alert generation is enabled (“yes”) for the corresponding sensor data (see snapshot above) stream. An alert e-mail and/or SMS is sent when an alarm condition is entered as well as when the alarm condition gets cleared.
If customer has not enabled alert generation (“no”) for a particular sensor data stream, no e-mail/SMS will be sent out but this event will be recorded and displayed in the “alarms” history window shown in the snapshot below.
Once an alert (e-mail and/or SMS) is sent out, another alert will not be sent out until the alarm condition gets automatically cleared or a different type of alarm condition is entered. For example, if the RH value increases beyond 80%, the chamber will remain in this alarm condition until the RH drops below (80 – 2.5) = 77.5 %. Similarly, if the RH falls below 40 %, the chamber will remain in this alarm condition until the RH rises above (40 + 2.5) = 42.5 %.
For more information on our products, please visit wisense.in.
For inquiries about our dashboard, please write to us at email@example.com.