Monthly Archives: July 2016
WSN1101L Radio
WSN1101CL
The WiSense WSN1101L Sub-Ghz wireless mesh node uses the CC1101 transceiver from TI. The CC1101 has a max power output of +10.8 dBm in the 865-867 MHz Band. The CC1101 has a special transmit mode in which it outputs an unmodulated continuous wave (CW) signal (sine wave). This mode is useful in testing the radio board’s performance. The snap below shows the radio board’s output with the CC1101 configured to generate a 10.8 dBm unmodulated continuous wave signal at 866 MHz . Note that in this setup, we had a WSN1101L connected to the spectrum analyzer’s input through a RF cable assembly. The spectrum analyzer is measuring an average channel power of 9.05 dBm. The power loss (+10.8 dBm – 9.05 dBm) can be attributed partly to the RF cable assembly.
WSN1101L Radio output captured by Spectrum Analyzer
If you are wondering why the frequency domain representation of a continuous sine wave is not a single thin vertical line – it is because of phase noise.
The pic below shows the setup – A WSN1101CL connected to a spectrum analyzer.
We are currently evaluating an RF front end module which will increase the range of our WSN1101L and WSN1101CL nodes by increasing the link budget in both the transmit path and the receive path. The max transmit power of our nodes will go up from +10 dBm to +30 dBm which is the maximum allowed power at the output of the radio in the Indian 865-867 MHz license free band. This IC has a low noise amplifier (LNA) to increase the link budget (thereby range) in the (RX) direction.
For more information please visit wisense.in
Hardware Update: New low profile WiSense Coordinator Node
The WSN1101CL is a low profile WiSense wireless mesh coordinator node. It includes the CC1101 high performance sub-ghz radio (from TI) and the MSP430G2955 micro-controller (from TI).
Node dimensions: 42 mm x 42 mm x 10 mm
The radio board has a U.FL antenna connector. We provide multiple antenna options.
- Whip antenna which can directly connect to the U.FL connector on the radio board
- Half-wave dipole 3 dbi antenna with SMA connector. Use a U.FL to SMA bulkhead RF cable assembly to connect the radio board to the antenna.
The WSN1101CL comprises of two PCBs. One PCB hosts the micro-controller while the other hosts the CC1101 radio. The micro board has a 128 Kilo-Byte serial EEPROM which can hold two complete firmware images. It also has another 256 byte EEPROM which also provides a hardwired and globally unique 64 bit MAC addresses.
The WSN1101CL has an on-board USB Mini-B port which can be used to connect to a laptop or Linux SBC such as the Raspberry PI. The USB Mini-B port provides power and serial connectivity.
The WSN1101CL comes pre-programmed out of the box to operate as a WiSense mesh network coordinator node operating in the 865-867 MHz license free band (in India). The network raw baud rate is 1200 bps. Max output power is +10 dBm. Receiver sensitivity @ 1200 bps and 1 % PER is around -110 dBm.
The coordinator node is responsible for setting up and maintaining a single instance of a WiSense LPWMN (low power wireless mesh network). It allocates a unique 16 bit address to each node which joins the network. It also serves as the gateway for the entire network. All communication between the nodes in the network and the outside world happens through the coordinator node.
WiSense provides a Linux/Cygwin based CLI to configure and query the WSN1101CL and associated LPWMN (low power wireless mesh network).
The Linux/Cygwin based CLI can be used (for example) to:
- Set the RF channel (channel 1 to channel 9) on which the LPWMN will operate.
- Set the 16 bit LPWMN identifier (LPWMN Id).
- List all the nodes in the network.
- Get/Set attributes on the Coordinator and other nodes in the network.
- Request the coordinator to reboot itself.
- Request any node in the network to reboot.
- Upgrade the firmware running on the Coordinator.
- Upgrade the firmware on any node in the network (over the air upgrade).
- Get information on the version of firmware running on the coordinator or any other node in the LPWMN.
- Monitor sensor data messages received from any node in the network
For more information visit http://www.wisense.in
WSN1101L Antenna Options
The WSN1101L low power Sub-Ghz wireless mesh module can be used to build both indoor and outdoor sensor/actuator nodes.
Outdoor deployments must be weather proof. WiSense offers low cost IP-65 (weather proof) ABS enclosures (80 mm x 80 mm x 55 mm) for this purpose. The enclosure lid can be transparent.
The WSN1101L has a (small) male U.FL connector on it’s radio board. A U.FL to SMA bulkhead cable assembly can be used to connect an external antenna while keeping all the electronics (the WSN1101L node and related electronics, batteries etc) within the weather proof enclosure. We offer a high performance omni-directional half wave dipole antenna which can be mounted outside the enclosure. The antenna has a male (threaded) SMA connector at it’s base which allows a strong mechanical connection to the female SMA bulk-head connector end of the RF cable assembly. This antenna is tuned for the 865-867 MHz license free ISM band (in India). A hole is drilled in the enclosure for the female SMA bulk-head connector. The latter is secured to the connector using a rubber o-ring, washer and nut. If done properly the enclosure remains weather proof. The RF cable assembly has a thin coaxial cable which is pretty flexible. This allows the cable assembly to be used in smaller enclosures. This RF cable assembly has a 50 Ohm (RF) impedance and can handle frequencies up to 11 GHz (far above 865-867 MHz at which the WSN1101L operates).
For indoor deployments, we offer a whip antenna which can be directly connected to the U.FL connector on the radio board. We also offer a smaller enclosure for indoor deployments.
WSN1101L inside a weather proof enclosure (ABS/IP-65). The RF board is connected to the external antenna through a flexible U.FL to SMA RF cable assembly. The enclosure lid is transparent. It is secured by four screws. You can see a rubber gasket (below the lid).
WSN1101L node with U.FL whip antenna (suitable for indoor usage).
WSN1101L inside a smaller enclosure suitable for indoor deployment. Enclosure is not weather proof. Dimensions : 76.2 mm x 76.2 mm x 25.4 mm (3″ x 3 ” x 1″).
WSN1101L inside a weather proof (IP65) ABS enclosure with non-transparent lid. The antenna is an omni-directional 3 dbi gain half-wave dipole tuned for the 865-867 MHz license free band. This particular node encloses a PCB mounted AC/DC power supply module, Li-Ion charger PCB and a Li-Ion battery in addition to a WSN1101L. Enclosure dimensions : 80 mm x 80 mm x 55 mm.
For more information on WiSense, please visit wisense.in.
