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Difference between revisions of "Kiln temperature controller"

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==General description==
 
==General description==
This circuit is intended to control a pottery oven. It uses the MAX6675 thermocouple-to-digital converter to measure oven temperatures. An oven schedule will consist of a list of (time, temperature) tuples. When started, the SX should work through the list of tuples and for each tuple:
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This circuit is intended to control a pottery oven. It uses the MAX6675 thermocouple-to-digital converter to measure oven temperatures. An oven schedule will consist of a list of (s, d)-tuples, where s stands for time in seconds and d for temperature in degrees Celcius. When started, the AVR should work through the list of tuples and for each tuple move to desired temperature d taking s seconds to get there.
* bring the oven temperature to the value given
 
* maintain that temperature for the time given
 
  
The circuit uses an LCD display, a rotary encoder, a small piezo speaker and two buttons for its user interface. The oven is controlled through relays. Since the oven will be in a shed and the users would like to monitor the ovens progress from home, the LCD display and speaker are wirelessly controlled through a 433Mhz transmitter/receiver pair. See the [[Wireless LCD display]] project (which is finished).
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The circuit uses an LCD display, a rotary encoder and two buttons for its user interface. The oven is controlled through a relay. Since the oven will be in a shed and the users would like to monitor the ovens progress from home, the controller will send its status periodically through a (cheap) 433Mhz transmitter. The  See the [[Wireless LCD display]] project (which is finished).
  
 
==Project notes==
 
==Project notes==
 
* [[Media:max6675.pdf|maxx6675 thermocouple-to-digital converter]] datasheet
 
* [[Media:max6675.pdf|maxx6675 thermocouple-to-digital converter]] datasheet
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==Project Status==
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;2010-06-23: Switched to AVR (from SX). Hardware platform now ready (max6675, LCD, LCD backlight control, rotary encoder, 2 switches, relay + driver, transmitter, receiver, led and programming header). First test with 'hardcoded' oven program successful. module tests of max6676, rotary encoder, LCD and relay successfully completed. Total hardware cost: around €33,-, including K-type thermocouple probe.
  
 
[[Image:layout_oven_controller.jpg|400px]]
 
[[Image:layout_oven_controller.jpg|400px]]
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[[Image:oven_controller_top.JPG]]
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[[Category:AVR]]

Revision as of 23:45, 23 June 2010

General description

This circuit is intended to control a pottery oven. It uses the MAX6675 thermocouple-to-digital converter to measure oven temperatures. An oven schedule will consist of a list of (s, d)-tuples, where s stands for time in seconds and d for temperature in degrees Celcius. When started, the AVR should work through the list of tuples and for each tuple move to desired temperature d taking s seconds to get there.

The circuit uses an LCD display, a rotary encoder and two buttons for its user interface. The oven is controlled through a relay. Since the oven will be in a shed and the users would like to monitor the ovens progress from home, the controller will send its status periodically through a (cheap) 433Mhz transmitter. The See the Wireless LCD display project (which is finished).

Project notes

Project Status

2010-06-23
Switched to AVR (from SX). Hardware platform now ready (max6675, LCD, LCD backlight control, rotary encoder, 2 switches, relay + driver, transmitter, receiver, led and programming header). First test with 'hardcoded' oven program successful. module tests of max6676, rotary encoder, LCD and relay successfully completed. Total hardware cost: around €33,-, including K-type thermocouple probe.

Layout oven controller.jpg File:Oven controller top.JPG