Re[2]: RYO network

["Pete Shew" <ukha_d@xxxxxxxxxxxxxxxxxx>]

Hi Frank,  I'm currently looking at the homebrew ICD2 pages - it seems
pretty easy to throw one together. If it works out OK, I make make a second
as comms debugging is always a taxing experience.

The 18F range is very tempting for the much improved instruction set apart
from CAN so I'm moving more in that direction. Is there an ICD for Atmel -
I couldnt see one. Simulators are OK, but you can't always simulate the
real world timings.

I am using assembler for my PIC projects - the PBX is still working well. I
feel you've got more contol over speed, size and variable allocation, but
then again I've not tried C on a PIC.

The CH project started as I've got two boilers in tandem running three
zones and hot water and a big bill. One of the boilers can usually be stood
down, but I like the idea of automatice switching, and using both for
startup loads and very cold weather. Other things I want to include are
taking account of outside temperature for startup time and water
temperature adjustment.  Plus the convenience of controls in the zones and
not just in the cupboard in our bedroom.

Pete


*********** REPLY SEPARATOR  ***********

On 27/03/2005 at 06:35 Frank Mc Alinden wrote:

>Hi Pete
>            Dave Mc Laughlin is the best person to ask regarding canbus
(he
>uses it for his boiler control) although he,s using the Atmel
>processors..with the can chips....
>
>>Any good reasons why I should shell out for an ICD 2 (or even
switch
>microprocessors) and >use pukka CAN?
>
>Just got the icd2 recently so i could start using the 16f88 pics as
well as
>the18f range ,but currently still using the 16f876 for my xPL
>projects....the icd2 isnt that expensive imo.....
>
>> HA? - it's part of my central heating control.
>
>Keep us posted on your progress.....are you coding in assembler or
HLL..???
>
>Frank
>
>
>
>----- Original Message -----
>From: "Pete Shew" <ukha_d@xxxxxxx>
>To: "UKHA" <ukha_d@xxxxxxx>
>Sent: Saturday, March 26, 2005 9:08 PM
>Subject: [ukha_d] RYO network
>
>
>>
>> I've got a requirement to connect a few PICs together and Cat 5
seems the
>logical choice for physical media. However, I need to choose a
protocol.
>CAN
>looks a likely candidate, but I'm working with PIC 17F877A and not the
much
>nicer PIC 18F458 and don't have the luxury of an inbuilt CAN engine.
The
>reason - I only have version 1 of the ICD.
>>
>> I also have space limitations and don't want to add an external
CAN chip.
>>
>> I don't want a bus master network, though if the case were strong
enough
>I
>could be persuaded., So I've currently got the idea of using CAN bus
>drivers
>driven using a standard UART with extra logic to detect
recessive/dominant
>collisions, and with a protocol loosely based on CAN within the
limitations
>of the hardware. The pseudo code looks like it should work OK, but I
know
>that debugging is going to be "interesting".
>>
>> Has anyone else been along this route with success or failure? Any
good
>reasons why I should shell out for an ICD 2 (or even switch
>microprocessors)
>and use pukka CAN?
>>
>> HA? - it's part of my central heating control.
>>
>> Pete
>>
>>
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>>
>>
>>
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>Yahoo! Groups Links
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