Description
LTE Cat NB1(NB-IoT) is a more modern and advanced way of Machine-to-machine communication than legacy GPRS connection. In comparison with GPRS, the NB-IoT connection has extremely low power consumption and is much more efficient. This Narrowband-IoT shield allows you to connect your Raspberry Pi to this new cellular network with the help of Quectel’s BC95 NB-IoT module.
Quectel BC95 is a high-performance LTE NB-IoT module offering a maximum data rate of 21.25Kbps downlink and 15.625kbps uplink. The NB-IoT shield has built-in temperature, humidity, light sensors, 3-axis accelerometer, a relay and more. Built-in SMD antenna lets you establish the connection right out of the package.
Features
- Fully compatible with Raspberry Pi models that have the 40-pin GPIO header (3, 2, B+, A+, Zero)
- Supported Protocol Stacks: IPv4/UDP/CoAP/LwM2M/Non-IP
- Frequency Band: EUROPE region coverage with the B20-800MHz band
- 12-Bit 4 Channel ADC
- 3-axis Accelerometer
- Humidity and Temperature Sensors
- Ambient Light Sensor
- Isolated Optocoupler Inputs
- 1-Wire Sensors Interface
- 3GPP TS 27.007 V14.3.0 and Quectel Enhanced AT Commands over UART port to Raspberry Pi is available
- Efficient and low quiescent current regulator circuit can hold up to 3.6A
- Micro SIM Card socket is easily reachable on the upside of the shield.
- Working temperature range: -30°C to +80°C
Key Applications
- Smart farming sensor
- Smart cities sensor
- Smart home sensor
- Internet of Things (IoT) sensor
- Smart door lock
- Smart lighting
- Smart metering
- Smart parking
- Smart city
- Home appliances
- Agricultural and environmental monitoring
Technical Details
Connection Types
UART: The UART pins are available to use, with 3.3V power domain, directly connected the 9600bps baud rate. The default data frame format is 8N1 (8 data bits, no parity, 1 stop bit).
Data Speeds
Downlink: 21.25Kbps @Single Tone
Uplink: 15.625kbps @Single Tone
Power Consumption (Typical)
- 3.6uA @PSM
- 2mA @Idle Mode, DRX=1.28s
- LTE Cat NB1 Connectivity:
- 220mA @Radio Transmission, 23dBm (B8/B5/B20)
- 100mA @Radio Transmission, 12dBm (B8/B5/B20/B28)
- 70mA @Radio Transmission, 0dBm (B8/B5/B20/B28)
- 65mA @Radio Reception
SMS
Point-to-point MO and MT
Text and PDU Mode
Enhanced Features
- DFOTA: Delta Firmware Upgrade Over the Air
- RAI: Release Assistance Indication
Warnings
Do not apply higher voltages and currents than those specified absolute electrical value for sensor inputs and relay connections.
Electrical
Pinout
Pin Descriptions
| Pin Number | BCM Pin | Pin Name | Description |
|---|---|---|---|
| 2 | 5V | 5V PWR | This pin is connected to the 5V power net. |
| 3 | GPIO 2 | SDA | I2C Serial Data |
| 4 | 5V | 5V PWR | This pin is connected to the 5V power net. |
| 5 | GPIO 3 | SCL | I2C Serial Data |
| 7 | GPIO 4 | 1-WIRE | Data line to communicate with 1-Wire sensors. |
| 8 | UART RX | BC95 TX | This pin functions as the serial data input to the module for UART communication. |
| 10 | UART TX | BC95 RX | This pin functions as the serial data output from the module for UART communication |
| 29 | GPIO 5 | IN-2 | When the voltage in the range 3.3-12V(max 15V!) is applied from the IN-2 input, this pin goes to LOW state. The default state is HIGH(pulled-up). |
| 31 | GPIO 6 | VDD_EXT | When BC95 powered on, VDD EXT pin switched to HIGH level. You can detect BC95 ON/OFF state by reading this pin. |
| 32 | GPIO 12 | IN-1 | When the voltage in the range 3.3-12V(max 15V!) is applied from the IN-1 input, this pin goes to LOW state. The default state is HIGH(pulled-up). |
| 36 | GPIO 16 | RESET | Reset the module by driving the reset pin to a HIGH-level voltage for +100ms at least. |
| 37 | GPIO 26 | RELAY | Relay control pin. When this pin is HIGH state, the relay is operated.(COMMON and NO will be connected.) |
| 38 | GPIO 20 | USER LED | Active HIGH, to switch on the USER LED, the pin’s state should be HIGH. |
| 40 | GPIO 21 | USER BUTTON | This pin is pulled-up by default. When the button is pressed, pin switches to LOW. |
| 6,9,14,25,30,34,39 | GND | GND | These pins are connected to ground. |
Electrical Characteristics of Pins
| Pin Number | BCM Pin | Pin Name | Description | Min | Typ. | Max. | Unit |
|---|---|---|---|---|---|---|---|
| 2 | 5V | 5V PWR | Power Supply | 4.8 | 5 | 5.25 | V |
| 3 | GPIO 2 | SDA | I2C Data | 3 | 3.3 | 3.6 | V |
| 4 | 5V | 5V PWR | Power Supply | 3 | 3.3 | 3.6 | V |
| 5 | GPIO 3 | SCL | I2C Clock | 3 | 3.3 | 3.6 | V |
| 7 | GPIO 4 | 1-WIRE | 1-Wire data | 3 | 3.3 | 3.6 | V |
| 8 | UART RX | BC95 TX | UART | 3 | 3.3 | 3.6 | V |
| 10 | UART TX | BC95 RX | UART | 3 | 3.3 | 3.6 | V |
| 29 | GPIO 5 | IN-2 | Input | 3 | 3.3 | 3.6 | V |
| 31 | GPIO 6 | VDD_EXT | Input | 3 | 3.3 | 3.6 | V |
| 32 | GPIO 12 | IN-1 | Input | 3 | 3.3 | 3.6 | V |
| 36 | GPIO 16 | RESET | Output | 3 | 3.3 | 3.6 | V |
| 37 | GPIO 26 | RELAY | Output | 3 | 3.3 | 3.6 | V |
| 38 | GPIO 20 | USER LED | Output | 3 | 3.3 | 3.6 | V |
| 40 | GPIO 21 | USER BUTTON | Input | 3 | 3.3 | 3.6 | V |
Layout
Schematic
You can download the schematic of Raspberry Pi NB-IoT Shield from this Github repository.
LEDs
- POWER (PWR): When the shield&module is powered up, this RED led turns on.
- USER (USER): The GREEN user led can be controlled by driving the GPIO 27 pin.
- CONNECTION (CON) : This BLUE led indicates the status of the module. When the connection is established and data is being transmitted/received, this led will blink at special intervals. This feature of the module is under development, will be activated on future firmware.
Buttons
- USER: This push button connected to GPIO21 and pulled up HIGH state by default. When you push the button, you will read LOW state from GPIO21.
- RESET: When the BC95 is in powered on, it can be reset by pushing the RESET button for at least 100ms. Also, driving GPIO16 to the HIGH state will cause a reset.
3-axis 12-bit/8-bit Digital Accelerometer | MMA8452Q
- The MMA8452Q is a smart, low-power, three-axis, capacitive, micromachine accelerometer with 12 bits of resolution. It has user selectable full scales of ±2 g/±4 g/±8 g with high-pass filtered data as well as non-filtered data available real-time.
- The accelerometer connected to Raspberry Pi via I2C. The I2C address is 0x1C.
- MMA8452Q’s interrupt pins are not connected.
12-Bit Analog-to-digital Converter | ADS1015
- The ADS1015 is precision, low-power, 12-bit, an analog-to-digital converter.
- Raspberry Pi can not measure analog inputs because it does not have internal ADC. However, with this external ADC, the ADS1015, you can read analog values with your Raspberry Pi.
- The ADC connected to Raspberry Pi via I2C. The I2C address is 0x49.
Ambient Light Sensor | ALS-PT19
- It’s a phototransistor close responsively to the human eye spectrum, light to current.
- It’s connected to ADC (ADS1015) as its analog output cannot be