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RE: Re: Serial protocol questions


  • Subject: RE: Re: Serial protocol questions
  • From: "DynamoBen" <ben@xxxxxxxxxxx>
  • Date: Mon, 24 Jan 2005 22:30:47 -0600


In that case it would just be 02,02

On the pic side I wait, (listen) for the first 02 (sync byte) and then
star=
t
collecting the rest of the data. The second 02 remains the device address.

BTW I don't want to take any credit for the protocol that I posted. I
thought it would be nice to encapsulate it for review.

-----Original Message-----
From: Frank Mc Alinden [mailto:fmcalind@xxxxxxx]=20
Sent: Monday, January 24, 2005 5:08 PM
To: ukha_xpl@xxxxxxx
Subject: Re: [ukha_xpl] Re: Serial protocol questions


Hi Ben


> STX =3D Start byte (02)
>
> Slave Addr =3D Slave Address 1-255 (0 =3D All devices)


What happens if the device addr is 02...??? ....I assume it sets a flag to
say it has rec the start cmd and when it rx,s the second (02h) it checks
th=
e
flag and if set assumes its addr or data ???

Frank


----- Original Message -----=20
From: "DynamoBen" <ben@xxxxxxx>
To: <ukha_xpl@xxxxxxx>
Sent: Tuesday, January 25, 2005 7:59 AM
Subject: Re: [ukha_xpl] Re: Serial protocol questions


>
> Here is what I was thinking. Give me your thoughts. This does not
address
> the Master-->XPL conversion.
>
> System Layout:
>
>
>
> RS232=E0Dedicated Master=E0RS485=E0Slave
>
>
>
> Protocol RS232=E0Master:
>
>
>
> <Slave Addr><Length><Command><Data.><Chk
Sum>
>
>
>
> Slave Addr =3D Slave Address 1-255 (0 =3D All devices)
>
> Length =3D Message Length including from Slave Addr to Check Sum
(4-255
bytes)
>
> Command =3D Single byte control messages (1 byte)
>
> Data =3D The actual Data to be processed by Slave (Variable Length)
>
> Chk Sum =3D Check sum this is a byte add of string (1 byte)
>
>
>
> Master RS485=E0Slaves
>
>
>
> <STX><Slave
Addr><Length><Command><Data.><Chk
Sum><ETX>
>
>
>
> STX =3D Start byte (02)
>
> Slave Addr =3D Slave Address 1-255 (0 =3D All devices)
>
> Length =3D Message Length including from Slave Addr to Check Sum
(4-255
bytes)
>
> Command =3D Single byte control messages (1 byte)
>
> Data =3D The actual Data to be processed by Slave (Variable Length)
>
> Chk Sum =3D Check sum this is a byte add of string (1 byte)
>
> ETX =3D End or Terminator Byte (03)
>
>
>
> ----- Original Message -----=20
> From: "DynamoBen" <ben@xxxxxxx>
> To: <ukha_xpl@xxxxxxx>
> Sent: Monday, January 24, 2005 2:56 PM
> Subject: Re: [ukha_xpl] Re: Serial protocol questions
>
>
> >
> > BTW 1/8 fuses on the data line is always a good idea.
> > ----- Original Message -----=20
> > From: "DynamoBen" <ben@xxxxxxx>
> > To: <ukha_xpl@xxxxxxx>
> > Sent: Monday, January 24, 2005 2:53 PM
> > Subject: Re: [ukha_xpl] Re: Serial protocol questions
> >
> >
> >>
> >> RS485 hubs are super easy to build. In fact you could mock
one up on a
> >> breadboard in under 30mins. (They are generally called opto
splitters)
> >>
> >> Parts Needed:
> >> Several 75176 chips (less than 32)
> >> Several 6N137 chips (this is for opto isloation)
> >>
> >> Data path is RS485-->75176 Input-->6N137
> >>
> >> Then this would be repeated for the outputs. Don't for get to
tie TX t=
o
> >> RX.
> >>
> >> This make sense?
> >>
> >>
> >> ----- Original Message -----=20
> >> From: "Frank Mc Alinden" <fmcalind@xxxxxxx>
> >> To: <ukha_xpl@xxxxxxx>
> >> Sent: Monday, January 24, 2005 2:46 PM
> >> Subject: Re: [ukha_xpl] Re: Serial protocol questions
> >>
> >>
> >>>
> >>> Hi Guys
> >>>        Have to agree with  Lehane that its better to have
lots of
small
> >>> devices than to make one that does all ...........
> >>> Would that mean then a rs485 hub would be required so
that it could b=
e
> >>> star
> >>> wired ??? anybody did a rs485 hub before ????
> >>>
> >>> Allowing the network to run at different baud rates is a
good idea
> >>> ,anything
> >>> i have done is 9600 , although i dont think 19200 would
be out of the
> >>> question for most pics...??
> >>>
> >>> The important thing to get this project going i think is
to get
started
> >>> on
> >>> the master device....
> >>>
> >>> Neil  do you have any current hardware to develope a
Master on ????
> >>>
> >>>> 2) Presumably the host software will do the
device/instance id->node
> >>>> number conversion and the device/instance config? -
Don't know what
> >>>> this
> >>> is
> >>>> yet ???
> >>>
> >>> Each node has a name / id and its configurable , so when
you put a ne=
w
> >>> device on the network it will sent out regular requests
"please
> >>> configure
> >>> me" known as config heartbeats....The master should
pick up this
message
> >>> and
> >>> pass it on to the xPL network....In xPL Manager under xPL
> >>> devices,subfolder
> >>> awaiting configuration the device should be listed
clicking on it the=
n
> >>> allows you to configure....The config info would get send
to the
Master
> >>> which passes it on to the new unit which would
reconfigure its self
and
> >>> immediately send out a regular heartbeat.....
> >>> Hope that makes sense ??
> >>>
> >>> Frank
> >>>
> >>>
> >>> ----- Original Message -----=20
> >>> From: "Neil Wrightson" <neilw@xxxxxxx>
> >>> To: <ukha_xpl@xxxxxxx>
> >>> Sent: Tuesday, January 25, 2005 7:21 AM
> >>> Subject: RE: [ukha_xpl] Re: Serial protocol questions
> >>>
> >>>
> >>>>
> >>>> Hi Lehane,
> >>>>
> >>>> 1) I made reference to the compiler I use purely
because it is a goo=
d
> >>>> compiler. Each different type of slave could be a
completely
different
> >>> micro
> >>>> and language - assembler, C, Basic Pascal etc etc.
The main thing is
> >>>> that
> >>>> handles its own task and interfaces to the required
485 network
> >>>> protocol.
> >>>>
> >>>> 2) Presumably the host software will do the
device/instance id->node
> >>>> number conversion and the device/instance config? -
Don't know what
> >>>> this
> >>> is
> >>>> yet ???
> >>>>
> >>>> 3) "Mmm!
> >>>> I'd caution against making the devices too complex.
Better have 10
> >>>> types (smaller/cheaper) than 1 do-everything and they
are likely to
> >>>> see the light of day faster. You can always put
two/three/four in on=
e
> >>>> box." - Exactly
> >>>>
> >>>>
> >>>> 4) "So I'd go for:
> >>>> 1 n-way DC input (maybe analogue) variations can
include on/off,
> >>>> momentary, dimmer action, etc.
> >>>> 2 n-way DC output (maybe PWM on some for LED's)
variations - opto,
> >>>> SSR, etc
> >>>> 3 LCD display driver
> >>>> 4 RFID (...and RFID to me is EPC/ISO 18000)
> >>>> 5 Universal IR (UIRT on 485)
> >>>> 6 Dallas touch and/or one wire sensors
> >>>> 7 MSR (Track 1/2/3)
> >>>> 8 Bar Code Reader (UPC/EAN/ITF/Code 39)
> >>>> 9 Analog input/output (0-5/10V)
> >>>> 10 .... "
> >>>>
> >>>> A) I was thinking of analogue inputs for switches
etc, adds
additional
> >>>> security to remote switches I.e. window reed switches
or PIR's
> >>>>
> >>>> B) What is "EPC/ISO 18000"
> >>>>
> >>>> C) What is MSR (Track 1/2/3)
> >>>>
> >>>>
> >>>>
> >>>> 5) "Agree on the power to the unit, although
12-15V maybe sufficient
as
> >>>> the power consumption is going to be pretty low on
most.
> >>>> Not sure about the audio..I think that belongs on
Ethernet in the
> >>>> digital domain. I guess you're looking at voice/audio
feedback but
> >>>> would you want output from every device? Or would you
command each
> >>>> amp on? "
> >>>> RS485 Cabling is generally as per the old coax
10base2, one long lin=
e
> >>>> with
> >>>> terminators on either end.
> >>>> With up to 32 devices on this line, that means 64
connections, each
> >>>> with
> >>>> it's own voltage drop. The higher you can have the
supply voltage th=
e
> >>>> less
> >>>> current in the supply lines the less voltage drop on
the cable and
the
> >>> less
> >>>> impact of voltage drops on the network connectors.
> >>>> A lot of filed devices requires 12VDC so you would at
least have to
add
> >>> 50%
> >>>> i.e. 18VDC for the interconnecting power supply. I
know of lots of
off
> >>>> the
> >>>> shelf 24VDC supplies out there. But, I think that as
long as we
design
> >>>> the
> >>>> system so that it can handle from 12..24VDC, we can
leave it up to
the
> >>>> individual.
> >>>>
> >>>> 6) As far as the audio goes, my intention was that we
use the speake=
r
> >>>> out
> >>> of
> >>>> the HA pc. Nothing fancy.
> >>>> I see this as been a separate plug in add on board to
the main slave
> >>>> terminal with a small amp etc.
> >>>>
> >>>>
> >>>> 7) RS485 Comms Speed
> >>>> For each slave the master must Tx a message and then
Rx a message. 3=
2
> >>> Slaves
> >>>> times * 2 * Packet size of say ten characters =3D 640
bytes. At 9600
baud
> >>> this
> >>>> would mean dial around would take 1.5 seconds. In
reality this would
be
> >>>> somewhat longer with internal delays etc. Hence the
reason that I
> >>> suggested
> >>>> 38400 baud. I know basic chips may have issues with
this. Again
perhaps
> >>> user
> >>>> definable 9600/38400.
> >>>> Build the network to your own needs.
> >>>>
> >>>>
> >>>> Neil.
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> written in a completely differant language or
> >>>>
> >>>>
> >>>> Regards,
> >>>>
> >>>> Neil Wrightson.
> >>>> -----Original Message-----
> >>>> From: g8kmh [mailto:lehane@xxxxxxx]
> >>>> Sent: Tuesday, 25 January 2005 12:46 AM
> >>>> To: ukha_xpl@xxxxxxx
> >>>> Subject: [ukha_xpl] Re: Serial protocol questions
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> I've dropped my response in below.
> >>>>
> >>>> Lehane
> >>>>
> >>>> --- In ukha_xpl@xxxxxxx, "Neil Wrightson"
<neilw@n...> wrote=
:
> >>>> > Hi Guys,
> >>>> >
> >>>> > 1) I'm all for a combined project.
> >>>> >
> >>>> > 2) I don't want to start another mine is better
than yours
> >>>> discussion, but,
> >>>> > I use AVR's :) I have a great compiler AVRCo
with true multitaskin=
g
> >>>> etc
> >>>>
> >>>> To some extent it is irrelevent to most end-users.
Few are going to
> >>>> change code, some will want prog'ed devices and most
a kit (or at
> >>>> least PCB and CPU).
> >>>>
> >>>> The protocol outline is doable across a wide range of
devices, indee=
d
> >>>> it needs to be interoperable.
> >>>>
> >>>> >
> >>>> > 3) I think that a dedicated 485 network
controller will be
> >>>> required. I think
> >>>> > the 485 comms will probably run about 38400
baud.
> >>>> >     A 16MHz AVR will happily look after this.
> >>>> >     The network controller will pass and receive
all state changes
> >>>> to the PC
> >>>> > as well as heart beats for each device.
> >>>> >     Comms to the PC could be 9600.
> >>>> >
> >>>>
> >>>> A separate controller has some advantages of
redundancy and
> >>>> interfacing with Win* or *nix.
> >>>>
> >>>> With xPL not on the wire then heartbeats can be
different internally
> >>>> to externally.
> >>>>
> >>>> Presumably the host software will do the
device/instance id->node
> >>>> number conversion and the device/instance config?
> >>>>
> >>>>
> >>>> > 4) I envisage that there be at least two types
of room controllers
> >>>> (Perhaps
> >>>> > we should start by settling on some names for
these things)
> >>>> >     a) Bedroom/kitchen/Living area Controller
wish list
> >>>> >         Display,
> >>>> >         Personnel Switches for lights, sound
muting etc,
> >>>> >         Data entry method, Set room alarm clock
time etc Sleep tim=
e
> >>>> for
> >>>> > lighting etc
> >>>> >         IR Transmitter, Turn telly off when I
fall asleep in bed,
> >>>> turn
> >>>> > ceiling fan off etc etc
> >>>> >         Personal ID method
> >>>> >         Sound
> >>>> >         Movement sensor interface
> >>>> >         Switch inputs for door & window reed
switches
> >>>> >
> >>>> >     b) Basic room as in garage/toilet/bathroom
wish list
> >>>> >         Personnel Switches for lights etc,
> >>>> >         Sound
> >>>> >         Movement sensor interface
> >>>> >         Switch inputs for door & window reed
switches
> >>>> >         Note - This is to be a cheaper version,
no display only
> >>>> beeper for
> >>>> > sound alerts, maybe a IR receiver for
configuration ??
> >>>> >
> >>>> > Hardware Solutions for above
> >>>> >         Display,
> >>>> > 16*2 LCD with LED backlight OR maybe a small
graphic LCD, could
> >>>> display
> >>>> > small icons for
> >>>> >
> >>>> > you have email, voice messages, phone callers
etc.
> >>>> >         Personnel Switches for lights
> >>>> etc,                             2..4
> >>>> > Tactile switches I.e. small PCB mount
> >>>> >         Light Control
> >>>> > either 240V relay or triac, triac allows
dimming, great for those
> >>>> wee stops
> >>>> > in the night
> >>>> >         Data entry method,
> >>>> > Universal TV remote. I can currently decode Sony
or RC5 signals
> >>>> >         IR Transmitter
> >>>> > IR led on controller as well as capability to
add an external IR
> >>>> led else
> >>>> > where in the room
> >>>> >
> >>>> > for better coverage if needed, I.e. Living room
with external LED
> >>>> for Stereo
> >>>> > etc.
> >>>> >         Personal ID method
> >>>> > Dallas 1 wire ibutton, A lot cheaper &
smaller than RFID!
> >>>> >         Sound
> >>>> > 2 Types, 1) Standard beeper. 2) Optional 1W
speaker with sound
> >>>> relaying from
> >>>> > controller Pc
> >>>> >
> >>>> > Probably a separate optional PCB.
> >>>> >         Movement sensor
> >>>> interface                                    As
> >>>> > suggested either a integrated unit actually on
the controller or a
> >>>> separate
> >>>> > security PIR
> >>>> >         Switch inputs for door & window reed
switches
> >>>> Standard style
> >>>> > of inputs on a micro 5..12V tolerant.
> >>>> >
> >>>> >         Power Supply and Signal
> >>>> >             I suggest that we use CAT5
> >>>> >             Power - 2 Pairs 1 pair for 0V and
one pair for +24V.
> >>>> >             Comms Signal  - 1 Pair
> >>>> >             Audio from PC - 1 Pair
> >>>> >             If we try to use the standard pin
outs for power over
> >>>> Ethernet
> >>>> > and data signals, nothing will be damaged if
> >>>> >             a wrong device is plugged in
somewhere.
> >>>> >             Although, I did see these devices as
being panel
> >>>> mounted on the
> >>>> > walls.
> >>>> >
> >>>> Mmm!
> >>>> I'd caution against making the devices too complex.
Better have 10
> >>>> types (smaller/cheaper) than 1 do-everything and they
are likely to
> >>>> see the light of day faster. You can always put
two/three/four in on=
e
> >>>> box.
> >>>> So I'd go for:
> >>>> 1 n-way DC input (maybe analog) variations can
include on/off,
> >>>> momentary, dimmer action, etc.
> >>>> 2 n-way DC output (maybe PWM on some for LED's)
variations - opto,
> >>>> SSR, etc
> >>>> 3 LCD display driver
> >>>> 4 RFID (...and RFID to me is EPC/ISO 18000)
> >>>> 5 Universal IR (UIRT on 485)
> >>>> 6 Dallas touch and/or one wire sensors
> >>>> 7 MSR (Track 1/2/3)
> >>>> 8 Bar Code Reader (UPC/EAN/ITF/Code 39)
> >>>> 9 Analog input/output (0-5/10V)
> >>>> 10 ....
> >>>>
> >>>> Agree on the power to the unit, although 12-15V maybe
sufficient as
> >>>> the power consumption is going to be pretty low on
most.
> >>>> Not sure about the audio..I think that belongs on
Ethernet in the
> >>>> digital domain. I guess you're looking at voice/audio
feedback but
> >>>> would you want output from every device? Or would you
command each
> >>>> amp on?
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> xPL Links: http://www.xplproject.org.uk
<http://www.xplproject.org.uk>
> >>>> http://www.xplhal.com <http://www.xplhal.com>
> >>>> http://www.xpl.myby.co.uk
> >>>> <http://www.xpl.myby.co.uk>
> >>>> To Post a Message: ukha_xpl@xxxxxxx
> >>>> To Subscribe:  ukha_xpl-subscribe@xxxxxxx
> >>>> To Unsubscribe:  ukha_xpl-unsubscribe@xxxxxxx
> >>>>
> >>>>
> >>>>
> >>>>   _____
> >>>>
> >>>> Yahoo! Groups Links
> >>>>
> >>>>
> >>>> * To visit your group on the web, go to:
> >>>> http://groups.yahoo.com/group/ukha_xpl/
> >>>> <http://groups.yahoo.com/group/ukha_xpl/>
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> >>>>
> >>>> [Non-text portions of this message have been removed]
> >>>>
> >>>>
> >>>>
> >>>> xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
> >>> http://www.xpl.myby.co.uk
> >>>> To Post a Message: ukha_xpl@xxxxxxx
> >>>> To Subscribe:  ukha_xpl-subscribe@xxxxxxx
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> >>>
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> >>>
> >>> xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
> >>> http://www.xpl.myby.co.uk
> >>> To Post a Message: ukha_xpl@xxxxxxx
> >>> To Subscribe:  ukha_xpl-subscribe@xxxxxxx
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> >>> Yahoo! Groups Links
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >>
> >> xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
> >> http://www.xpl.myby.co.uk
> >> To Post a Message: ukha_xpl@xxxxxxx
> >> To Subscribe:  ukha_xpl-subscribe@xxxxxxx
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> >> Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >
> >
> >
> > xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
> > http://www.xpl.myby.co.uk
> > To Post a Message: ukha_xpl@xxxxxxx
> > To Subscribe:  ukha_xpl-subscribe@xxxxxxx
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> >
> >
> >
> >
> >
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> >
>
>
>
> xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
http://www.xpl.myby.co.uk
> To Post a Message: ukha_xpl@xxxxxxx
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