HCS Thermostat Project
As you can see this is the
testing stage of the project.
Using a www.simmetry.com Touch screen and a Micro basic Dev system.
Sample showing the readout |
Picture of the Dev Board |
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You can see the mess of wires |
This shows the external LCD display option |
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This is a start on the Schematic, It is missing the power circuit and a bunch of small details. |
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2-15-04 Basic Features for the RS485 Thermostat
module.
Display Screens:
Main screen,
Current Temp
Mode (Auto,Heat,Cool,Off)
Cool Set point
Heat Set point
Curent system status (Fan on/off), (Heat or Cool) on
Touch Screen - 4 options
Direct access to Both Setpoints, Touch on Heat or Cool with go to Set-point change screen
System Mode - Toggles (Auto, Heat,Cool,Off)
Menu - Enters configuration menu
Set-Point Screen,
Display's SP to change
Touch screen - 3 options,
Up
Down
Done - exit change.
Will exit to Main Screen in 20 seconds without Touch
System Setup Screen 1/3
Touch screen - 3 options
Default SP - The SP when the system powers up or error.
Max/Min set point, This is set to shut off all relays if temp is reached.
Next Screen -
System Set Screen 2/3
Touch Screen - 3 options
Module number - Set's the Module Number
Fan Mode - Toggles (On/Auto)
Next Screen -
System Set Screen 3/3
Touch Screen - 2 options
Network - toggles (Enable/Disable) to allow SP changes.
Next Screen -
If no Touch in 20 seconds the system will return back to the Main Screen.
Network Commands:
Uses # ,Checksum packets only. I will respond to Answerman MAN# commands or Thermostat commands.
MAN# commands that it will process are:
MAN# SD 000 000 - Setpoint #1 and #2 (Heat/Cool)
MAN# QE -Returns Control Status, Current Temp, Heat SP and Cool SP
MAN# QC -Returns C:0002 to setup the HCS properly for Answerman and the Thermostat
Control_status var byte ;Byte that hold current statuts of the control
network_Enable var control_status.bit0 ;Switch Setting
heat var control_status.bit1 ;Heat cycle on/off
cool var control_status.bit2 ;Cool cycle on/off
heat_enable var control_status.bit3 ;Heat Enable
cool_enable var control_status.bit4 ;Cool Enable , both = auto
fan_mode var control_status.bit5 ;Fan Status 0=auto 1=ON
fan var control_status.bit6
Thermostat Commands, Can be sent via
the HCS.
SL# SPH Set_point Heat
SL# SPC Set_point Cool
SL# SM (A-Auto,H-Heat,C-Cool,O-Off)
SL# SM(0-Fan Auto,1-Fan On)
Future commands will include the SL- Reply commands, Reset system, Display Text
Major Hardware components,
PIC16F876
EEPROM 24C65 for Holding future Screen Data
MAX3100 Used to communicate with the Touch Panel
DS1302 Time Chip, Future Expansion to a Stand alone set-back controller
Graphics Touch Screen or Standard Char display LCD -
The system is designed to use the Serial Touch Screen panel or a standard Character display with the additions of buttons.
DS75176 RS485 interface - Currently set to 9600 baud HCS, but can handle much faster rates.
Set to run off the Heating/Cooling power system, but this has not been checked yet.
PCB is designed to use ExpressPCB prototype service- 3 boards $59.00 - I have added a bunch of stuff on one board as I use the same board for other projects.
The system has been running without fail for over a month. Prior to that I shut down the display with Static, but the Pic was running fine.
Future expansion Idea's,
Time Chip Implementation,
Animated Graphics for the Display
Display Back lighting control
Software Changing of the RS485 Baud Rate
Storing Run Data - Like how long the system runs (Day/Week/Month)
Filter Change reminder
Some of the idea's are on hold until the next revision of the Display is done. This unit works well, but is limited on Graphics use and I can't figure where to put the Current time on the Display.
The Baud Rate Change will be next. 2004
Here are Copies of the Current Program, and PCB layout. Keep in mind the Program will change some as soon as I get the PCB’s due to some different mapping.
Express PCB Schematic – Not 100% complete
Links:
http://www.simmetry.com/ The Display Used.
www.basicmicro.com Basic Micro for the PIC
Ron Bihler