{{pfw:banner.png}} ====== Mesh network ====== {{https://user-images.githubusercontent.com/11397265/157903902-66324963-a68f-43bf-bdf6-fc22b96b761f.jpg|mesh in action}}\\ **Three Egel-kits communicating** ===== The idea ===== Using standard wireless transceivers to form a self constructing mesh network. Basically each node has the same structure, the only difference is the node address.\\ The transceiver used here is the nRF24L01 or the Chinese clone named [[https://datasheet.lcsc.com/lcsc/2202241830_Nanjing-Zhongke-Microelectronics-Si24R1_C14436.pdf|SI24R1]]. ===== Built on top ===== The basis for this example are these files: [[en:pfw:spi|SPI]], [[:nrf24l01_basic_2024l01dn_20g2553-01a.f|Basic 24L01dn]] file and the [[en:pfw:bit-array|bit array]], these are used for the driver of the network layer. This driver uses **dynamic payload** to optimise the troughput of the network. * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/Generic-Forth|Generic Forth]], version of the mesh network\\ * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/G2553-&-F149|G2553 & F149]], noForth mesh network version\\ * [[https://github.com/project-forth-works/project-forth-works/tree/main/Communication-Protocols/Wireless-Communication/Mesh-network/GD32VF103|GD32VF103]], noForth mesh network version\\ * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/FR59xx|MSP430FR5949]], noForth mesh network version ==== Files required to build a working node ==== * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/SPI/GD32VF/noForth/SPI0%20v100.f|An SPI driver for your CPU]], the example link goes to the GD32VF103 driver * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/nRf24L01%2B/GD32VF/noForth/basic%2024L01dn%20GD32VF-01a.f|A driver for the used transceiver]], again for the GD32 Risc-V MPU and some tools * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/GD32VF103/mesh%20node%20v4.1rf%20GD32dn-01a.f|Then the mesh network layer]], and we should have a functioning node * [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/GD32VF103/Tools|Finally you may add some tools]], a network build routine, PING, etc. For noForth and especially for the [[https://www.tindie.com/products/Willem_O/egel-kit-board-set-for-msp430g2553-no-parts/|Egel-kit]] you are ready now. The photo on top shows you three Egel-kits communicating :)\\ When you use another MPU and/or Forth system you may adapt the [[https://github.com/project-forth-works/project-forth-works/tree/main/Communication-Protocols/Wireless-Communication/Mesh-network/Generic-Forth|generic version]] to your needs. ===== Flexible RF settings ===== The most important RF setting are build into the word ''%%SETRF%%'' this word sets the following parameters: * RF-channel number; 0 to 125 * Scan transmit power; -18db to 0db * Transmit power during normal use; -18db to 0db * Communication bitrate; 250 Kbit, 1 Mbit or 2 Mbit * Unique node address; 0 to max. node number (15 in this example) ===== Payload structure ===== The **Dynamic payload** format is 1 to 32 bytes. For this implementation the minimum payload size is 3 bytes (the command, destination & origin). This is because the node handler does a check on the destination before accepting a command. The complete payload is described in the table below. ^ 0 ^ 1 ^ 2 ^ 3 ^ 4 ^ 5 to 31 ^ | Command | Dest. | Orig. | Sub node | Admin | d00 to d1A | 0 pay> = Command for destination 1 pay> = Destination node 2 pay> = Origin node 3 pay> = Address of sub node 4 pay> = Administration byte 5 to 31 pay> = Data 0x1A (#26) bytes ===== Time out on network commands ===== Since network commands can be lost, a time-out on the response to the transmitted command is necessary. This time-out can be constructed with a built-in timer, or alternatively by using a built-in cycle counter.\\ This code example is for the GD32VF103 Risc-V microcontroller: hex code TICK ( -- u ) \ Read half (low 32-bits) of 64-bit rdcycle counter sp -) tos .mov tos B00 zero csrrs \ Read low counter next end-code decimal : MS ( ms -- ) 104000 * \ Convert MS to CPU ticks (CPU-clock/1000) tick >r \ Save tick counter begin tick r@ - \ Calc. ticks passed over u< 0= until \ Larger or equal to given ticks? r> 2drop ; \ Yes ready This structure is used in the word ''%%%%'' this word catches the response from the addressed node but only within the given time period.\\ An example: ''%%: ON ( node -- ) ch * >node 40 ; \ Send power on command%%'' ===== Node command interpreter ===== Here is a complete list of the commands of the node command interpreter. It is also known as //the handler// within this code example. ^ Token ^Function ^ | ''F'' |Execute Forth command string | | ''|'' |Stop free running program | | | | | ''*'' |Power output on | | ''_'' |Power output off | | | | | ''I'' |Give node info | | ''H'' |Give node connection info | | ''P'' |Respond on a ping | | ''N'' |Give free node number | | | | | ''s'' |Scan and note any node within reach | | ''i'' |Gather node type info from other nodes | | ''h'' |Gather network connection data | | | | | ''^'' |Receive hop data from other node | | ''@'' |Receive type info from node | | ''R'' |Register a new node to the network | | ''}'' |Answer when an external command is finished| | ''#'' |Receive free node number from network | ===== Interactive node ===== The node command interpreter is integrated in a the word ''%%NODE%%''. A sample implementation is shown here. The word ''%%GET?%%'' is a primitive outer interpreter as is commonly used in many Forth systems. It reads and stores characters when a key was hit. With the escape key we are leaving this node interpreter loop. A backspace removes typos, after the enter key the string is evaluated, an error leaves this loop too. === Example code === hex 0 value NR create BUF 20 allot : GET? ( -- 0|1B ) 0 key? if \ Key pressed? key dup 1B = if or exit then \ Yes, exit on escape char! dup 0D = if \ Is it ENTER? drop space buf nr evaluate \ Yes, interpret string 0 to nr cr \ New line t? 0= if ." N>" then \ Display prompt when tracer is off else dup 8 = if \ Is it backspace? emit bl emit 8 emit -1 \ Yes, remove char else dup emit buf nr + c! 1 \ Normal char, show & save then +to nr \ Adjust number of chars then then ; : NODE ( -- ) startnode ( tron ) troff 0 to nr begin begin handler? until get? until ; This program is originally written in noForth. In noForth the serial input and output is vectored. Replacing the key vector does the same as the ''%%NODE%%''program. : XKEY) ( -- c ) begin handler? until key) ; The last line in the word ''%%STARTNODE%%'' contains this line, so after startnode is executed the interactive node is ready. ['] xkey) to 'key \ Add KEY & node handler to KEY ===== NODE command set ===== If you want to try out this mesh network implementation, these are the words to play with. Note that each node also contains a primitive event handler. This handler uses a pin as input for a switch to ground. This switch alternately activates the words ''%%ALL-ON%%'' or ''%%ALL-OFF%%''. ^Word ^Stack ^Description ^ |''%%.STATUS%%'' |( -- ) |Show most important RF data | |''%%.ALL%%'' |( -- ) |Show network connection data | |''%%REGISTER%%''|( -- ) |Connect myself to an existing network | |''%%ON%%'' |( +n -- ) |Activate power output on node +n | |''%%OFF%%'' |( +n -- ) |Deactivate power output on node +n | |''%%ALL-ON%%'' |( -- ) |Activate all outputs on the network | |''%%ALL-OFF%%'' |( -- ) |Deactivate all outputs on the network | |''%%STOP%%'' |( +n -- ) |Halt any free running program on node +n| |''%%>F%%'' |( +n ccc -- )|Execute the forth word ccc on node +n | |''%%SCANX%%'' |( -- ) |Scan & note direct accessible nodes | ---- {{https://user-images.githubusercontent.com/11397265/157905223-70621a30-4d84-4d40-b706-f30acef52bed.jpg|scanx}}\\ **SCANX result** ===== Network tools ===== The mesh network code adds some additional words for constructing new functions above the basic node command interpreter. These are: ^Word ^Stack ^Function ^ |''%%ALL%%'' |( -- a ) |Address of a BIT-table with all found nodes | |''%%DIRECT%%'' |( -- a ) |Address of a BIT-table with direct accessable nodes | |''%%INDIRECT%%''|( -- a ) |Address of a BIT-table with indirect accessable nodes | |''%%#MAP%%'' |( -- +n ) |Leave the size of a bitmap | |''%%GET*%%'' |( u a -- 0|b ) |Check if node +n present in bit-array a? | |''%%*CLR%%'' |( u a -- ) |Remove node +n from bit-array a | |''%%*COUNT%%'' |( a -- +n ) |Leave number of nodes found in bitmap a | |''%%>USER%%'' |( a -- ) |Copy nodes to node accu for app programmer | |''%%>WORK%%'' |( a -- ) |Copy nodes to node accu for internal functions | |''%%NEXT?%%'' |( a -- 0|u -1 )|Leave node number of the first used node in bitmap a & erase the bit | |''%%RUN%%'' |( -- ) |Allow a program to run free | |''%%HALT?%%'' |( -- f ) |Alternative KEY? to stop node programs | |''%%%%'' |( u -- ) |Wait +n milliseconds & respond to external network commands, leave after an } was received| |''%%>OTHERS%%'' |( c -- ) |Send node command c to all nodes noted in WORK with a timeout of 1024 ms | |''%%FINISH%%'' |( -- ) |End network buildup with adding node type information | === Generic forth example code === hex : RUN-FORW ( -- ) \ Running light on all outputs in my network run begin \ Reset stop flag all >user \ Copy all nodes table to user table begin user next? while \ Get next available node number dup on 100 \ Activate output on that node shortly off 30 repeat halt? until ; \ Until a key is pressed or a STOP command was received ----

  • [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/Generic-Forth/Tools/Build%20(3.9d).f|BUILD]], constructs a (hopping) mesh network

  • [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/Generic-Forth/Tools/Ping-2.f|PING]], check node connection/availability

  • [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/Generic-Forth/Tools/Mesh-demos.f|DEMO's]], that activate the node outputs in different ways

  • [[https://github.com/project-forth-works/project-forth-works/blob/main/Communication-Protocols/Wireless-Communication/Mesh-network/Generic-Forth/Tools/automesh.f|Simple demo]], primitive network build routine & running light demo

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**All steps taken by the ''%%BUILD%%'' routine**\\ {{https://user-images.githubusercontent.com/11397265/157910410-addf6e4d-2e14-478c-8426-47e8435576b7.jpg|Build done color}}