Table of Contents:
1. Introduction
1.1 What is N95S31B NB-IoT Sensor Node
The Dragino N95S31B is a NB-IoT Temperature and Humidity Sensor for Internet of Things solution. It is used to measure the surrounding environment temperature and relative air humidity precisely, and then upload to IoT server via NB-IoT network*.
The temperature & humidity sensor used in N95S31B is SHT31, which is fully calibrated, linearized, and temperature compensated digital output from Sensirion, it provides a strong reliability and long-term stability. The SHT31 is fixed in a waterproof anti-condensation casing for long term use.
N95S31B supports different uplink methods include TCP, MQTT, UDP and CoAP for different application requirement.
N95S31B is powered by8500mAh Li-SOCI2 battery, It is designed for long term use up to several years. (Real-world battery life depends on the use environment, update period. Please check related Power Analyze report).
* make sure you have NB-IoT coverage locally.
1.2 Features
- NB-IoT Bands: B1/B3/B8/B5/B20/B28 @H-FDD
- Monitor Temperature & Humidity via SHT31
- AT Commands to change parameters
- Uplink on periodically
- Downlink to change configure
- IP66 Waterproof Enclosure
- Ultra-Low Power consumption
- AT Commands to change parameters
- Micro SIM card slot for NB-IoT SIM
- 8500mAh Battery for long term use
1.3 Specification
Common DC Characteristics:
- Supply Voltage: 2.1v ~ 3.6v
- Operating Temperature: -40 ~ 85°C
NB-IoT Spec:
- - B1 @H-FDD: 2100MHz
- - B3 @H-FDD: 1800MHz
- - B8 @H-FDD: 900MHz
- - B5 @H-FDD: 850MHz
- - B20 @H-FDD: 800MHz
- - B28 @H-FDD: 700MHz
Battery:
- Li/SOCI2 un-chargeable battery
- Capacity: 8500mAh
- Self Discharge: <1% / Year @ 25°C
- Max continuously current: 130mA
- Max boost current: 2A, 1 second
1.4 Applications
- Smart Buildings & Home Automation
- Logistics and Supply Chain Management
- Smart Metering
- Smart Agriculture
- Smart Cities
- Smart Factory
1.5 Pin Definitions
N95S31B use the mother board from NBSN95 which as below.
1.5.1 Jumper JP2
Power on Device when put this jumper.
1.5.2 BOOT MODE / SW1
1) ISP: upgrade mode, device won't have any signal in this mode. but ready for upgrade firmware. LED won't work. Firmware won't run.
2) Flash: work mode, device starts to work and send out console output for further debug
1.5.3 Reset Button
Press to reboot the device.
1.5.4 LED
It will flash:
- When boot the device in flash mode
- Send an uplink packet
2. Use N95S31B to communicate with IoT Server
2.1 How it works
The N95S31B is equipped with a NB-IoT module, the pre-loaded firmware in N95S31B will get environment data from sensors and send the value to local NB-IoT network via the NB-IoT module. The NB-IoT network will forward this value to IoT server via the protocol defined by N95S31B.
The diagram below shows the working flow in default firmware of N95S31B:
2.2 Configure the NDDS75
2.2.1 Test Requirement
To use NDDS75 in your city, make sure meet below requirements:
- Your local operator has already distributed a NB-IoT Network there.
- The local NB-IoT network used the band that NSE01 supports.
- Your operator is able to distribute the data received in their NB-IoT network to your IoT server.
Below figure shows our testing structure. Here we have NB-IoT network coverage by China Mobile, the band they use is B8. The NDDS75 will use CoAP(120.24.4.116:5683) or raw UDP(120.24.4.116:5601) or MQTT(120.24.4.116:1883)or TCP(120.24.4.116:5600)protocol to send data to the test server
2.2.2 Insert SIM card
Insert the NB-IoT Card get from your provider.
User need to take out the NB-IoT module and insert the SIM card like below:
2.2.3 Connect USB – TTL to NDDS75 to configure it
User need to configure NDDS75 via serial port to set the Server Address / Uplink Topic to define where and how-to uplink packets. NDDS75 support AT Commands, user can use a USB to TTL adapter to connect to NDDS75 and use AT Commands to configure it, as below.
Connection:
USB TTL GND <----> GND
USB TTL TXD <----> UART_RXD
USB TTL RXD <----> UART_TXD
In the PC, use below serial tool settings:
- Baud: 9600
- Data bits: 8
- Stop bits: 1
- Parity: None
- Flow Control: None
Make sure the switch is in FLASH position, then power on device by connecting the jumper on NDDS75. NDDS75 will output system info once power on as below, we can enter the password: 12345678 to access AT Command input.
Note: the valid AT Commands can be found at: https://www.dragino.com/downloads/index.php?dir=NB-IoT/NDDS75/
2.2.4 Use CoAP protocol to uplink data
Note: if you don't have CoAP server, you can refer this link to set up one: http://wiki.dragino.com/xwiki/bin/view/Main/Set%20up%20CoAP%20Server/
Use below commands:
AT+PRO=1 // Set to use CoAP protocol to uplink
AT+SERVADDR=120.24.4.116,5683 // to set CoAP server address and port
AT+URI=5,11,"mqtt",11,"coap",12,"0",15,"c=text1",23,"0" //Set COAP resource path
For parameter description, please refer to AT command set
After configure the server address and reset the device (via AT+ATZ ), NDDS75 will start to uplink sensor values to CoAP server.
2.2.5 Use UDP protocol to uplink data(Default protocol)
- AT+PRO=2 // Set to use UDP protocol to uplink
- AT+SERVADDR=120.24.4.116,5601 // to set UDP server address and port
- AT+CFM=1 // If the server does not respond, this command is unnecessary
2.2.6 Use MQTT protocol to uplink data
- AT+PRO=3 //Set to use MQTT protocol to uplink
- AT+SERVADDR=120.24.4.116,1883 //Set MQTT server address and port
- AT+CLIENT=CLIENT //Set up the CLIENT of MQTT
- AT+UNAME=UNAME //Set the username of MQTT
- AT+PWD=PWD //Set the password of MQTT
- AT+PUBTOPIC=NDDS75_PUB //Set the sending topic of MQTT
- AT+SUBTOPIC=NDDS75_SUB //Set the subscription topic of MQTT
MQTT protocol has a much higher power consumption compare vs UDP / CoAP protocol. Please check the power analyze document and adjust the uplink period to a suitable interval.
2.2.7 Use TCP protocol to uplink data
- AT+PRO=4 // Set to use TCP protocol to uplink
- AT+SERVADDR=120.24.4.116,5600 // to set TCP server address and port
2.2.8 Change Update Interval
User can use below command to change the uplink interval.
- AT+TDC=600 // Set Update Interval to 600s
NOTE:
1. By default, the device will send an uplink message every 1 hour.
2.3 Uplink Payload
In this mode, uplink payload includes in total 14 bytes
Size(bytes) | 6 | 2 | 2 | 1 | 2 | 1 |
|---|---|---|---|---|---|---|
| Value | Device ID | Ver | BAT | Signal Strength | Distance (unit: mm) | Interrupt |
If we use the MQTT client to subscribe to this MQTT topic, we can see the following information when the NDDS751 uplink data.
The payload is ASCII string, representative same HEX:
0x72403155615900640c6c19029200 where:
Device ID: 0x724031556159 = 724031556159
Version: 0x0064=100=1.0.0
BAT: 0x0c6c = 3180 mV = 3.180V
Signal: 0x19 = 25
Distance: 0x0292= 658 mm
Interrupt: 0x00 = 0
2.4 Payload Explanation and Sensor Interface
2.4.1 Device ID
By default, the Device ID equal to the last 6 bytes of IMEI.
User can use AT+DEUI to set Device ID
Example:
AT+DEUI=A84041F15612
The Device ID is stored in a none-erase area, Upgrade the firmware or run AT+FDR won't erase Device ID.
2.4.2 Version Info
Specify the software version: 0x64=100, means firmware version 1.00.
For example: 0x00 64 : this device is NDDS75 with firmware version 1.0.0.
2.4.3 Battery Info
Ex1: 0x0B45 = 2885mV
Ex2: 0x0B49 = 2889mV
2.4.4 Signal Strength
NB-IoT Network signal Strength.
Ex1: 0x1d = 29
0 -113dBm or less
1 -111dBm
2...30 -109dBm... -53dBm
31 -51dBm or greater
99 Not known or not detectable
2.4.5 Distance
Get the distance. Flat object range 280mm - 7500mm.
For example, if the data you get from the register is 0x0B 0x05, the distance between the sensor and the measured object is
0B05(H) = 2821(D) = 2821mm.
2.4.6 Digital Interrupt
Digital Interrupt refers to pin GPIO_EXTI, and there are different trigger methods. When there is a trigger, the NDDS75 will send a packet to the server.
The command is:
AT+INTMOD=3 //(more info about INMOD please refer AT Command Manual).
The lower four bits of this data field shows if this packet is generated by interrupt or not. Click here for the hardware and software set up.
Example:
0x(00): Normal uplink packet.
0x(01): Interrupt Uplink Packet.
2.4.7 +5V Output
NDDS75 will enable +5V output before all sampling and disable the +5v after all sampling.
The 5V output time can be controlled by AT Command.
AT+5VT=1000
Means set 5V valid time to have 1000ms. So the real 5V output will actually have 1000ms + sampling time for other sensors.
2.5 Downlink Payload
By default, NDDS75 prints the downlink payload to console port.
Examples:
Set TDC
If the payload=0100003C, it means set the END Node's TDC to 0x00003C=60(S), while type code is 01.
Payload: 01 00 00 1E TDC=30S
Payload: 01 00 00 3C TDC=60S
Reset
If payload = 0x04FF, it will reset the NDDS75
- INTMOD
Downlink Payload: 06000003, Set AT+INTMOD=3
2.6 LED Indicator
The NDDS75 has an internal LED which is to show the status of different state.
- When power on, NDDS75 will detect if sensor probe is connected, if probe detected, LED will blink four times. (no blinks in this step is no probe)
- Then the LED will be on for 1 second means device is boot normally.
- After NDDS75 join NB-IoT network. The LED will be ON for 3 seconds.
- For each uplink probe, LED will be on for 500ms.
2.7 Firmware Change Log
Download URL & Firmware Change log
Upgrade Instruction: Upgrade_Firmware
2.8 Battery Analysis
2.8.1 Battery Type
The NDDS75 battery is a combination of an 8500mAh Li/SOCI2 Battery and a Super Capacitor. The battery is none-rechargeable battery type with a low discharge rate (<2% per year). This type of battery is commonly used in IoT devices such as water meter.
The battery is designed to last for several years depends on the actually use environment and update interval.
The battery related documents as below:
2.8.2 Power consumption Analyze
Dragino battery powered product are all runs in Low Power mode. We have an update battery calculator which base on the measurement of the real device. User can use this calculator to check the battery life and calculate the battery life if want to use different transmit interval.
Instruction to use as below:
Step 1: Downlink the up-to-date DRAGINO_Battery_Life_Prediction_Table.xlsx from: https://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/Battery_Analyze/
Step 2: Open it and choose
Product Model
Uplink Interval
Working Mode
And the Life expectation in difference case will be shown on the right.
2.8.3 Battery Note
The Li-SICO battery is designed for small current / long period application. It is not good to use a high current, short period transmit method. The recommended minimum period for use of this battery is 5 minutes. If you use a shorter period time to transmit LoRa, then the battery life may be decreased.
2.8.4 Replace the battery
The default battery pack of NDDS75 includes a ER26500 plus super capacitor. If user can't find this pack locally, they can find ER26500 or equivalence without the SPC1520 capacitor, which will also work in most case. The SPC can enlarge the battery life for high frequency use (update period below 5 minutes).
3. Access NB-IoT Module
Users can directly access the AT command set of the NB-IoT module.
The AT Command set can refer the BC35-G NB-IoT Module AT Command: https://www.dragino.com/downloads/index.php?dir=datasheet/other_vendors/BC35-G/
4. Using the AT Commands
4.1 Access AT Commands
See this link for detail: https://www.dragino.com/downloads/index.php?dir=NB-IoT/NDDS75/
AT+<CMD>? : Help on <CMD>
AT+<CMD> : Run <CMD>
AT+<CMD>=<value> : Set the value
AT+<CMD>=? : Get the value
General Commands
AT : Attention
AT? : Short Help
ATZ : MCU Reset
AT+TDC : Application Data Transmission Interval
AT+CFG : Print all configurations
AT+CFGMOD : Working mode selection
AT+INTMOD : Set the trigger interrupt mode
AT+5VT : Set extend the time of 5V power
AT+PRO : Choose agreement
AT+WEIGRE : Get weight or set weight to 0
AT+WEIGAP : Get or Set the GapValue of weight
AT+RXDL : Extend the sending and receiving time
AT+CNTFAC : Get or set counting parameters
AT+SERVADDR : Server Address
COAP Management
AT+URI : Resource parameters
UDP Management
AT+CFM : Upload confirmation mode (only valid for UDP)
MQTT Management
AT+CLIENT : Get or Set MQTT client
AT+UNAME : Get or Set MQTT Username
AT+PWD : Get or Set MQTT password
AT+PUBTOPIC : Get or Set MQTT publish topic
AT+SUBTOPIC : Get or Set MQTT subscription topic
Information
AT+FDR : Factory Data Reset
AT+PWORD : Serial Access Password
5. FAQ
5.1 How to Upgrade Firmware
User can upgrade the firmware for 1) bug fix, 2) new feature release.
Please see this link for how to upgrade: http://wiki.dragino.com/xwiki/bin/view/Main/Firmware%20Upgrade%20Instruction%20for%20STM32%20base%20products/#H2.HardwareUpgradeMethodSupportList
Notice, NDDS75 and LDDS75 share the same mother board. They use the same connection and method to update.
6. Trouble Shooting
6.1 Connection problem when uploading firmware
6.2 AT Command input doesn't work
In the case if user can see the console output but can't type input to the device. Please check if you already include the ENTER while sending out the command. Some serial tool doesn't send ENTER while press the send key, user need to add ENTER in their string.
7. Order Info
Part Number: NSDDS75
8. Packing Info
Package Includes:
- NSE01 NB-IoT Distance Detect Sensor Node x 1
- External antenna x 1
Dimension and weight:
- Device Size: 13.0 x 5 x 4.5 cm
- Device Weight: 150g
- Package Size / pcs : 15 x 12x 5.5 cm
- Weight / pcs : 220g
9. Support
- Support is provided Monday to Friday, from 09:00 to 18:00 GMT+8. Due to different timezones we cannot offer live support. However, your questions will be answered as soon as possible in the before-mentioned schedule.
- Provide as much information as possible regarding your enquiry (product models, accurately describe your problem and steps to replicate it etc) and send a mail to support@dragino.com