General Purpose Tower Plug-in (TWRPI) socket allowing direct access to a selection of sensor plug-ins via I2C. A SN132 USB Dongle is also included with the TWR-RF-SNAP. The USB Dongle features the RF100 RF Engine based on a Freescale MC9S08 MCU and the Freescale MC13191 radio. The USB dongle provides a communication portal to a host computer via USB.
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A block diagram for the TWR-RF-SNAP is shown in the figure below. GPIO Expansion Header TWRPI Socket I2C, Analog, GPIO GPIO Photocell UART Analog Sensor SM700 Synapse Wireless 802.15.4 RF Engine Temp. Analog Sensor LEDs UART Interface Reset Pushbuttons Figure 1 - TWR-RF-SNAP Block Diagram TWR-RF-SNAP User’s Manual...
An image of the TWR-RF-SNAP with callouts is shown in the figure below. Figure 2 - TWR-RF-SNAP Image 2 Reference Documents The documents listed below should be referenced for more information on the Freescale Tower system and the TWR-RF-SNAP. Refer to http://freescale.com/tower...
Elevator connector Installing into the Tower System: In additional to functioning standalone, the TWR-RF-SNAP is designed to be used in the Freescale Tower System. When inserted into the Tower System a Tower MCU module can utilize the TWR-RF- SNAP to relay information to additional SNAP nodes, including the provided SN132 USB Dongle. The TWR-RF-SNAP can also access compatible peripheral modules directly using I2C and SPI.
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Figure 3 - Freescale Tower System Overview TWR-RF-SNAP User’s Manual Page 7 of 22...
3.2 IEEE 802.15.4 RF Engine The TWR-RF-SNAP features the Synapse Wireless SM700 IEEE 802.15.4 RF Engine. The SM700 RF Engine is based on the Freescale MC13224V transceiver platform. The SM700 comes with SNAP® preloaded and ready to perform out of the box. SNAP is Synapse’s award-winning, mesh network operating system that provides wireless connectivity for Internet-to-machine and machine-to-machine communications.
3.3 On-board Sensors, Inputs, and Indicators The following interfaces are implemented in the TWR-RF-SNAP to allow for user interaction. Temperature Sensor: - Connected to ADC Ch. 1 (physical pin 9 of the SM700) – SNAP GPIO 31 - Low-Power Linear Active Thermistor IC...
3.4 Expansion Interfaces The following interfaces allow for expandability of the TWR-RF-SNAP. TWPRI Connector: - Freescale standard connector for General Purpose Tower Plug-ins (TWRPIs) - Allows for plug-in of several different sensors – ex.TWRPI-MMA7660 Accelerometer - Interfaces to sensors via I...
ADC: - ADC1 has the capability to use an on-board 2.5V precision voltage reference GPIO Expansion Header: - The GPIO header exposes the following pins for use external to the TWR-RF-SNAP board: GPIO Header (J6) Pin Description SNAP GPIO_28 / Keyboard Interrupt 6 (KBI_6) Vcc (3.3V)
3.5 SNAP SN132 USB Dongle The SNAP SN132 USB Dongle is included with the TWR-RF-SNAP. The SN132 features an RF100 RF Engine. It is not only its own free-standing node in the SNAP network, but also provides the PC and Portal software a bridge into the SNAP network.
Software Features This section provides more details about the software features and functionality of the TWR-RF-SNAP including the Synapse Wireless Portal IDE and python based SNAPpy scripts. 3.6 SNAP / SNAPpy Synapse's technology is an Internet-enabled, auto-forming, multi-hop, mesh network Operating SNAP®...
The MAC address is printed on the label of each SNAP device. For a quick overview of installing the Synapse Portal IDE and the necessary USB drivers refer to the TWR-RF-SNAP Lab Guide. The Default View of Portal IDE consists of the following key panels and tool bars: Main Toolbar, Node View Panel, Node Info Panel, Node Info Toolbar, and Event Log Panel.
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Event Log Figure 5 - Portal IDE Application With the SN132 USB Dongle connected to the PC running the Portal IDE and the TWR-RF-SNAP powered externally and within range of the SN132, the application will identify the USB Dongle as an available SNAP Bridge Device on Port USB0.
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Figure 6 - SNAP Bridge Device Connect The application will then attempt to identify all available Nodes available in the network as seen in the figure below. The TWR-RF-SNAP will be identified as a SNAPTower Node (Device Type: TWR_SNAP). Figure 7 - SNAPTower in Portal TWR-RF-SNAP User’s Manual...
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SNAP Node is first selected in the Node View panel. For example, to upload a new script to the TWR-RF-SNAP Tower Module, you must first ensure that the SNAPTower Node is selected in the Node Info panel as shown in the image below.
Switch connects SM700 GPIO 23 to GND when pressed. Pin can be used as Switch 3 Push Button Pressed an interrupt pin to wake the SM700 from sleep. Switch 4 Push Button Pressed Resets the SM700 TWR-RF-SNAP User’s Manual Page 18 of 22...
5 Electromechanicals 5.1 Elevator Connections The TWR-RF-SNAP features two expansion card-edge connectors that interface to Elevator boards in a Tower System: the Primary and Secondary Elevator connectors. Table 1 provides the pinout for the Primary and Secondary Elevator Connector. An “X” in the “Used” column indicated that there is a connection from the TWR-MEM to that pin on the Elevator connector.
5.2 Tower Form-Factor The TWR-RF-SNAP is designed for the Freescale Tower System as a side mounting peripheral and complies with the electrical and mechanical specification as described in Freescale Tower Electromechanical Specification. Figure 10 - Tower Board size TWR-RF-SNAP User’s Manual...