Done By: Amnon Balanov & Yosef Solomon Supervisor: Boaz Mizrachi Project ID: d02310

 Small sensors, with very low power consumption  Planted under roads  Performing monitoring of road maintenance status

 Based on a PIC24 micro-processor  Networking (two alternatives): o 2.4 GHz enabled by a MRF24J40 IEEE Tx/Rx. o 433 MHz enabled by a MRF49XA Tx/Rx.  Networking will run MiWi (Microchip propriatory S/W stack) ***All components are made by Microchip.

The design and implementation of a networking S/W stack who’s functions will be: 1. Transmissions of aquired data to a PC via similar unit 2. Parsing commands received from PC station 3. WAKE interrupts from sleep - for sensing sessions

 Tx/Rx ◦ Communications with the PC unit  microSD memory chip ◦ Stores aquired data  PIC interrupts ◦ Wake/Transmission interrupts

Extra Board PICtail Evaluation Board – Explorer 16 MicroCTRL - PIC24FJ256GB110 Sensor Array Networking MRFJ40MB OR MRF49XA MEM- Flash & SRAM MEM- microSD SPI

 Internal flash Program Memory- 256kB ◦ Current tests show 10% usage  SRAM Data Memory- 16kB ◦ Current tests show 10% usage ◦ We will have a double buffer, a block length each, for communications (block=1kB; currently)  3 SPI Ports ◦ We will use one for the MRF & one for the µSD.

Uses 2.4GHz RF Uses O-QPSK modulation. Receiver FIFO- 144 byte, interrupts when a whole packet was received. Transmitter FIFO- 128 byte. Packet header length ~20 Bytes (TBD) Power: mA Working ~2 µA Sleeping

 Uses 433MHz RF  Uses FSK modulation.  Receiver FIFO- 16 bit, interrupts when full up to a certain point (configurable).  Transmitter Registers- two 1-byte Registers, similar use to the PIC double buffer.  Packet header length ~10 Bytes (TBD)  Power: mA Working 0.3 µA Sleeping

 MRF24J40 ◦ 250 kbps transmission speed  MRF49XA ◦ kbps digital transmission speed ◦ 256 kbps analog transmission speed  PIC24FJ256GB110 ◦ computational power of 16 MIPS ◦ sampling rate of 500 ksps  microSD ◦ reads and writes are in the MB/s range

 Definition and support the following working modes: ◦ Store samples (SS): Samples are stored in non-volatile memory for long period. ◦ Transmit samples (TS): Samples are read and transmitted from non-volatile memory through Wireless/UART/USB. ◦ Online sample and transmit (OST): Samples are read from sensor and then transmitted through UART/USB/Wireless, using internal SRAM memory (double buffer mechanism), without access to non-volatile memory.

 The device is activated using a well defined CLI (Command Line Interface).  The command line strings are received from either: ◦ TXRX wireless port ◦ USB port ◦ UART port ◦ Internal ROM table (Configuration table)  Each command will be executed, and a prompt prefix, followed by the command result, will be returned to the command origin source (TXRX, USB or UART).

 We will write a parser converting the different commands to a short field divided command.  Work on the parser is in its early stages.  For example: ◦ eeprom ◦ |5 bit command code| |3 bit sub-command| |8-bit optional|

 As was decided, we use the MiWi SW Stack. ◦ MiWi is a proprietary stack designed by Microchip, free to use.  The stack is implemented as general as possible and suits to the proposed HW networking modules.  We use the MiWi P2P protocol.

 The MiWi Protocol is divided into two parts: ◦ MiApp - upper level used to connect our application with the MiWi P2P protocol ◦ MiMAC - Using the MiMAC layer, we can easily switch between different RF transceivers such as MRF24J40 and MRF49XA.

 This layer will give 5 major interfaces: ◦ Initialization- allows configuration of selected hardware. ◦ Hand-shaking-allows discovering and connecting to peers and network. ◦ Receiving- allows receiving information over the air. ◦ Transmitting- allows sending information over the air. ◦ Extended Functionality- allows environment noise and power saving control.

 The MiMAC Layer allows us the abstraction of the Transceiver driver- we use it regardless of the driver used (at least in theory)  Mainly implements the MiApp API

Allows the easy configuration of the whole application:  Switching between Transceivers  Enabling/Disabling different functions of the SW stack  Further Development- Allows choosing the Protocol

 TXInit() ◦ Initialize network parameters. ◦ The sensor creates a network.  TXBatchInit() ◦ Initialize a new batch.  TXBlock() ◦ Transmits block of size 1KB.  TXStop() ◦ Ends transmission.  TXRXDeviceTasks() ◦ This function will take care of the transceiver periodic tasks (handle TX and RX tasks).

INIT Send Command Interpret command & Send Data Go To Sleep Receive Data New/End Session The sensor sidePC side

 In order to comply with time constraints of other parts of the WiStone we will test to see how big a payload we can use.  In case we see a packet’s transmission cannot be interrupted and in order to allow easy coordination, we will make the transmission of a packet atomic (non-preemptive).

 The two Transceivers support a sleep mode.  They save the current status on configuration registers to allow easy wake up.  The only way to wake up the transcievers is through pre-programmed timers on the transceivers or the PIC.  We need to figure out how to allow access not at a pre-determined time.

 Finishing software development & basic testing (3 weeks)- ◦ Completing code for:  The Main Loop functions.  Writing and documenting the parser (1 week)  Outdoors Testing (1 week)-Testing the network capabilities under simulated conditions.  Wrap-Up (1-2 weeks)- ◦ End of term presentation ◦ End of Project Report* Est. Total: 6-7 weeks. *Might be delayed because of Exam period