Not a question, just a wibble...

Got one of these for testing (no affiliation etc etc):

http://www.heatmisershop.co.uk/produ...%252dENTS.html

Looks quite nice, reasonably sane interface (bar the low level config which
is weird).

4 temp levels per day and 5/2 *or* 7 day modes. Remote probes, programmable
offsets, frost protection, holiday modes, and local temp overrides - it
seems to have everything...

There are versions with less features too.

Anyway, couldn't resist, so I hooked it up to my linux box with an RS232-485
converter and after a bit of buggering about, plus reading the protocol
docs:

http://www.heatmiser.co.uk/support/question.php?ID=6

I managed to remote command it (teccie people, see footnote).

I like

It's not radio, but that's not a problem for me...

Cheers

Tim

Footnote:

Here's a rougharsed bit of sample code to set the holiday mode to 3 days:

#!/usr/bin/perl
use strict;
use warnings;

use Digest::CRC qw(crcccitt);

my @msg = (
0x01, # target address 1-32
0x0c, # Frame len
0x81, # Our address
0x01, # 1= write, 0 = read
0x18, # DCB index to access, hi
0x00, # DCB index to access, lo
0x02, # Data len to write, lo
0x00, # Data len to write, lo
3 * 24, # 3 days, in hours, lo part
0x00, # high part
);


my $dat = '';
foreach my $b (@msg)
{
$dat .= chr($b);
}

my $crc = crcccitt($dat);
my $crclo = $crc & 0xff;
my $crchi = $crc 8;

# Slap a CCITT CRC on the end
my $packet = $dat . chr ($crclo) . chr ($crchi);

print $packet;

#################

And fire it off with:

perl test.pl | socat STDIN /dev/ttyS0,raw,echo=0,b4800


#################

Next I have to do a frame decoder. They seem to have missed a trick. No
obvious way to resynchronise after a broken/corrupted frame (other people
might use SLIP encoding or some other reliable way to demark frames).

Probably have to do something like "no data for a second or more, then next
data will be a new frame".

Tim S wrote:

Next I have to do a frame decoder. They seem to have missed a trick. No
obvious way to resynchronise after a broken/corrupted frame (other people
might use SLIP encoding or some other reliable way to demark frames).

Probably have to do something like "no data for a second or more, then next
data will be a new frame".


Is the protocol "command response" - i.e. a response elicited by each
command, or does it chatter away asynchronously?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm coughed up some electrons that declared:

Tim S wrote:

Next I have to do a frame decoder. They seem to have missed a trick. No
obvious way to resynchronise after a broken/corrupted frame (other people
might use SLIP encoding or some other reliable way to demark frames).

Probably have to do something like "no data for a second or more, then
next data will be a new frame".


Is the protocol "command response" - i.e. a response elicited by each
command, or does it chatter away asynchronously?



Hi John,

It's a single master mutli slave half duplex (shared TX/RX pair) system - so
it is elicited response only.

I see where you're going - you think: send command, wait upto n-time for
data, if good frame OK, if broken frame then reset state and send next
command (in fact the manual states the master must retry upto 5 times and
write commands are ACK'd, except in broadcast mode).

I agree - it's not disasterous, but some clean frame delimiting would be
nice. SLIP works very well for this IME. Can make the decoder slightly
simpler.

On an aside - I bought some CANbus interface chips to play with (quid each).
Higher level CAN protocols can manage bus arbitration with priority holdoff
for multimaster systems, or as the chips just handle the media layer, one
could implement any system and take benefit of a fairly solid media layer.
If it's good enough for cars, it should handle my house

Cheers

Tim

Tim S wrote:

I see where you're going - you think: send command, wait upto n-time for
data, if good frame OK, if broken frame then reset state and send next
command (in fact the manual states the master must retry upto 5 times and
write commands are ACK'd, except in broadcast mode).

Not even that complicated... do the sort of thing you do on a real time
system (assuming the response message indicates the current state,
rather than indicating that an event has occurred) you just bash out a
command update to it every so often and cache the response (if any). Use
that for accessing current state rather than the message itself. That
way your pool of status is kept fresh, but you don't actually care if a
message is missed since you are only going to get valid that that is a
little stale - say 500ms or whatever polling period you go for.

I agree - it's not disasterous, but some clean frame delimiting would be
nice. SLIP works very well for this IME. Can make the decoder slightly
simpler.

Perhaps a STX ETC framing would have helped - but for such a small
message it probably does not matter, since its transit time is short in
comparison to the link idle time. It is also unlikely to introduce any
delay between outgoing bytes - especially at 2.28ms/byte!

On an aside - I bought some CANbus interface chips to play with (quid each).
Higher level CAN protocols can manage bus arbitration with priority holdoff
for multimaster systems, or as the chips just handle the media layer, one
could implement any system and take benefit of a fairly solid media layer.
If it's good enough for cars, it should handle my house

Yup, a novel addressing scheme; using "comes from" addresses rather than
"goes to".



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Tim S wrote:
Not a question, just a wibble...

Got one of these for testing (no affiliation etc etc):

http://www.heatmisershop.co.uk/produ...%252dENTS.html

Looks quite nice, reasonably sane interface (bar the low level config which
is weird).

snip

Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.

Ha ha ha ha ha ha ha.

Sorry, deep tech, sample code, idylic domestic scene...

Does not compute.

click. whirch. shting. does not compute.
click. whirch. shting. does not compute.
click. whirch. shting. does not compute.

--
(Well I found it funny)

Devany coughed up some electrons that declared:

Tim S wrote:
Not a question, just a wibble...

Got one of these for testing (no affiliation etc etc):


http://www.heatmisershop.co.uk/produ...%252dENTS.html

Looks quite nice, reasonably sane interface (bar the low level config
which is weird).

snip

Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.
Ha ha ha ha ha ha ha.

She's turning it to max temperature override to make the room heat up faster
of course, silly... In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

Sorry, deep tech, sample code, idylic domestic scene...

I can assure you sir there are no idylic domestic scenes in my house ;-

And no-one round here can cope with thermostats either. Which is why I like
the look of these. Fiddle the override and it clunks back to normal at the
next switching time. There's a keypad lockout too. And remote programming
means I can potentially reload the programmes no matter how many times
people fiddle with them.

See that advantage now?

Does not compute.

click. whirch. shting. does not compute.
click. whirch. shting. does not compute.
click. whirch. shting. does not compute.


Does sir require some WD40 for sir's brain?

Tim S writes:

Devany coughed up some electrons that declared:
Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.

She's turning it to max temperature override to make the
room heat up faster of course, silly...

Which, with an ordinary thermostat it will, subjectively.
With the thermostat in operation the heat turns off as soon
as the air reaches the set temperature (modulo some latency
in the radiators), and it'll cool down quite quickly if the
walls are still cold. With the thermostat set to max it'll
keep heating, so the walls will warm up quicker, resulting
in reaching a subjectively comfortable temperature quicker
(and then overshooting it). So naturally, people who are
used to this behaviour (and prefer being too warm to too
cold) will do the same thing even if the thermostat is
cleverer about it. Unless the display says something more
informative. ("Brr it's cold in here, I'm trying as hard as
I can to get it warm, honest" might do the trick).

In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

I do wish people would make a distinction between women and
"girlies" (for want of a better term). Most of the women I
know (and I admit to having been fairly selective about who
I get to know) understand thermostats and such.

--
Jón Fairbairn
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2009-01-31)

"Tim S" wrote in message
...
Devany coughed up some electrons that declared:

Tim S wrote:
Not a question, just a wibble...

Got one of these for testing (no affiliation etc etc):


http://www.heatmisershop.co.uk/produ...%252dENTS.html

Looks quite nice, reasonably sane interface (bar the low level config
which is weird).

snip

Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.
Ha ha ha ha ha ha ha.

She's turning it to max temperature override to make the room heat up
faster
of course, silly...

The same principal applies to women and ovens.

In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

And the girlfriend has just asked where I keep my sewing kit! What planet is
she on?

Adam

"Jon Fairbairn" wrote in message
...
Tim S writes:

Devany coughed up some electrons that declared:
Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.

She's turning it to max temperature override to make the
room heat up faster of course, silly...

Which, with an ordinary thermostat it will, subjectively.
With the thermostat in operation the heat turns off as soon
as the air reaches the set temperature (modulo some latency
in the radiators), and it'll cool down quite quickly if the
walls are still cold. With the thermostat set to max it'll
keep heating, so the walls will warm up quicker, resulting
in reaching a subjectively comfortable temperature quicker
(and then overshooting it). So naturally, people who are
used to this behaviour (and prefer being too warm to too
cold) will do the same thing even if the thermostat is
cleverer about it. Unless the display says something more
informative. ("Brr it's cold in here, I'm trying as hard as
I can to get it warm, honest" might do the trick).

In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

I do wish people would make a distinction between women and
"girlies" (for want of a better term). Most of the women I
know (and I admit to having been fairly selective about who
I get to know) understand thermostats and such.

--
Jón Fairbairn
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2009-01-31)

"Jon Fairbairn" wrote in message
...
Tim S writes:

Devany coughed up some electrons that declared:
Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.

She's turning it to max temperature override to make the
room heat up faster of course, silly...

Which, with an ordinary thermostat it will, subjectively.
With the thermostat in operation the heat turns off as soon
as the air reaches the set temperature (modulo some latency
in the radiators), and it'll cool down quite quickly if the
walls are still cold. With the thermostat set to max it'll
keep heating, so the walls will warm up quicker, resulting
in reaching a subjectively comfortable temperature quicker
(and then overshooting it). So naturally, people who are
used to this behaviour (and prefer being too warm to too
cold) will do the same thing even if the thermostat is
cleverer about it. Unless the display says something more
informative. ("Brr it's cold in here, I'm trying as hard as
I can to get it warm, honest" might do the trick).

In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

I do wish people would make a distinction between women and
"girlies" (for want of a better term). Most of the women I
know (and I admit to having been fairly selective about who
I get to know) understand thermostats and such.


I am fairly selective with women. I have never asked any of them of them if
they can use a room thermostat. Do you only select women who are hot? I do.
I have a probe that takes readings of their temperature and dampness.

Adam

Jon Fairbairn coughed up some electrons that declared:

Tim S writes:

Devany coughed up some electrons that declared:
Picture, top right of your link, shows elegant female hand adjusting
temperature while, presumable, guests sit in soft focus luxury.

She's turning it to max temperature override to make the
room heat up faster of course, silly...

Which, with an ordinary thermostat it will, subjectively.
With the thermostat in operation the heat turns off as soon
as the air reaches the set temperature (modulo some latency
in the radiators), and it'll cool down quite quickly if the
walls are still cold. With the thermostat set to max it'll
keep heating, so the walls will warm up quicker, resulting
in reaching a subjectively comfortable temperature quicker
(and then overshooting it). So naturally, people who are
used to this behaviour (and prefer being too warm to too
cold) will do the same thing even if the thermostat is
cleverer about it. Unless the display says something more
informative. ("Brr it's cold in here, I'm trying as hard as
I can to get it warm, honest" might do the trick).

In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

I do wish people would make a distinction between women and
"girlies" (for want of a better term). Most of the women I
know (and I admit to having been fairly selective about who
I get to know) understand thermostats and such.


Woosh!

Sorry - I should have added a smilie ;-

John Rumm wrote:
Tim S wrote:

I see where you're going - you think: send command, wait upto n-time
for data, if good frame OK, if broken frame then reset state and
send next command (in fact the manual states the master must retry
upto 5 times and write commands are ACK'd, except in broadcast mode).

Not even that complicated... do the sort of thing you do on a real
time system (assuming the response message indicates the current
state, rather than indicating that an event has occurred) you just
bash out a command update to it every so often and cache the response
(if any). Use that for accessing current state rather than the
message itself. That way your pool of status is kept fresh, but you
don't actually care if a message is missed since you are only going
to get valid that that is a little stale - say 500ms or whatever
polling period you go for.
I agree - it's not disasterous, but some clean frame delimiting
would be nice. SLIP works very well for this IME. Can make the
decoder slightly simpler.

Perhaps a STX ETC framing would have helped - but for such a small
message it probably does not matter, since its transit time is short
in comparison to the link idle time. It is also unlikely to introduce
any delay between outgoing bytes - especially at 2.28ms/byte!

On an aside - I bought some CANbus interface chips to play with
(quid each). Higher level CAN protocols can manage bus arbitration
with priority holdoff for multimaster systems, or as the chips just
handle the media layer, one could implement any system and take
benefit of a fairly solid media layer. If it's good enough for cars,
it should handle my house

Yup, a novel addressing scheme; using "comes from" addresses rather
than "goes to".

Why don't I have the faintest idea what you two are talking about?

Is it anything to do with Dilithium crystals?



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman coughed up some electrons that declared:

Why don't I have the faintest idea what you two are talking about?

Is it anything to do with Dilithium crystals?


If it is, then I want the green alien girl - they're cute, even though they
take you for everything they can get.

:-

"Tim S" wrote in message
...
Not a question, just a wibble...

Got one of these for testing (no affiliation etc etc):

http://www.heatmisershop.co.uk/produ...%252dENTS.html

Looks quite nice, reasonably sane interface (bar the low level config
which
is weird).

4 temp levels per day and 5/2 *or* 7 day modes. Remote probes,
programmable
offsets, frost protection, holiday modes, and local temp overrides - it
seems to have everything...

There are versions with less features too.

Anyway, couldn't resist, so I hooked it up to my linux box with an
RS232-485
converter and after a bit of buggering about, plus reading the protocol
docs:

http://www.heatmiser.co.uk/support/question.php?ID=6

I managed to remote command it (teccie people, see footnote).

I like

It's not radio, but that's not a problem for me...

Cheers

Tim

Snip

Wossit for other than controlling yer heating then?
or could I link it to me Windoze box and using Nokia 5800 port into it and
switch on/off me boiler?

R coughed up some electrons that declared:

Wossit for other than controlling yer heating then?
or could I link it to me Windoze box and using Nokia 5800 port into it
and switch on/off me boiler?

Windows? spit

The Medway Handyman wrote:

Yup, a novel addressing scheme; using "comes from" addresses rather
than "goes to".

Why don't I have the faintest idea what you two are talking about?

I am sure most of the words make sense - even if the ordering is a bit
strange ;-)

Is it anything to do with Dilithium crystals?

Yup - on buses that fit inside cars and presumably, buses! Just make
sure you are not wearing a red polo shirt before beaming down for the
first time!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Tim S" wrote in message
...
R coughed up some electrons that declared:

Wossit for other than controlling yer heating then?
or could I link it to me Windoze box and using Nokia 5800 port into it
and switch on/off me boiler?

Windows? spit

*nix *puke*

Tim S writes:

Jon Fairbairn coughed up some electrons that declared:
In women-land, thermostat is just a rotary on-off
switch with silly numbers written on it.

I do wish people would make a distinction between women and
"girlies" (for want of a better term). Most of the women I
know (and I admit to having been fairly selective about who
I get to know) understand thermostats and such.


Woosh!

Post-structuralism.

--
Jón Fairbairn

Jon Fairbairn coughed up some electrons that declared:

Post-structuralism

Ow - my brain cell! I just glanced at the Wikipedia article for that(!)

R coughed up some electrons that declared:


"Tim S" wrote in message
...
R coughed up some electrons that declared:

Wossit for other than controlling yer heating then?
or could I link it to me Windoze box and using Nokia 5800 port into it
and switch on/off me boiler?

Windows? spit

*nix *puke*

A real man does not need to wave his OS in the air by way of comparison of
magnitude, he is content simply knowing that his *is* longer and stronger
and able to stay the course where others drop their core and wilt
ungracefully.

;-

Tim S wrote:
Jon Fairbairn coughed up some electrons that declared:

Post-structuralism

Ow - my brain cell! I just glanced at the Wikipedia article for
that(!)

I understood more of that than I did of the conversation between you & John
:-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman coughed up some electrons that declared:

Tim S wrote:
Jon Fairbairn coughed up some electrons that declared:

Post-structuralism

Ow - my brain cell! I just glanced at the Wikipedia article for
that(!)

I understood more of that than I did of the conversation between you &
John
:-)



Ah - a classics man. I'm more of a plilistine

Tim S wrote:
The Medway Handyman coughed up some electrons that declared:

Tim S wrote:
Jon Fairbairn coughed up some electrons that declared:

Post-structuralism
Ow - my brain cell! I just glanced at the Wikipedia article for
that(!)
I understood more of that than I did of the conversation between you &
John
:-)



Ah - a classics man. I'm more of a plilistine

And the correct form of address to a classics graduate?

"Big mac and chips please!" ;-)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:


And the correct form of address to a classics graduate?

Usually it is "How would you like your tea, Permanent Secretary?"