https://www.marcelpost.com/wiki/index.php?action=history&feed=atom&title=Mcu_0050-handheld-tempsensorMcu 0050-handheld-tempsensor - Revision history2026-04-30T00:08:43ZRevision history for this page on the wikiMediaWiki 1.39.17https://www.marcelpost.com/wiki/index.php?title=Mcu_0050-handheld-tempsensor&diff=573&oldid=prevAdmin at 10:33, 27 November 20112011-11-27T10:33:00Z<p></p>
<p><b>New page</b></p><div>{{Infobox<br />
| name = 0050-ds1820-tempsensor<br />
| image = [[File:Tempsensor-t84.jpg|150px]]<br />
| imagecaption = prototype<br />
| author = Marcel Post<br />
| mcu = ATtiny85<br />
| initial_release_date = Month Year<br />
| last_modified_date = Month Year<br />
| pcb_layers = 2<br />
| project_status = in development<br />
| category = [[Electronics]]<br />
}}<br />
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DS18S20 based Handheld Temperature sensor, for use with [[Mcu 0062-LCD-48x84-RC-Enclosure-top-pcb]].<br />
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==Description==<br />
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Years ago I started a similar project, creating a hand-held temperature sensor using a PIC16F84 with four 7-segment displays. The original project still works very well but I would like some more features added, such as:<br />
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* better display (using the Nokia 48x84 monochrome LCD instead of four 7-segment displays)<br />
* support for multiple DS1820 sensors using the one-wire protocol<br />
* better accuracy (PIC-based device has half-degree accuracy, this device will have 2 decimals accuracy)<br />
* optimising the code to get the most out of battery life (current PIC-based device does 2.7mA @ 3.09V, early tests show I can get down to 1.95mA, that's about 25% better)<br />
* store values (data logging) using EEPROM over i2c and graphical display of past values and trends<br />
* setting thresholds and signaling over and under-temperature events (for use as a thermostat)<br />
* wireless transmission of (stored) values<br />
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One of my preferences for this project is to design custom PCB's that fits inside the Jaycar HB5610 Remote Control Enclosure.<br />
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The code for this project also formed the basis for [[mcu_0055-rs232-tempsensor]].<br />
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[[File:Tempsensor-pic16f84-01.jpg]] <br />
[[File:Tempsensor-pic16f84-02.jpg]]<br />
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The original project, based on the PIC16F84 using four 7-segment displays and running off two 1.5V AA batteries.<br />
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==Timeline==<br />
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* 2011-11-27 Ordered 1x PCB with BatchPCB. Only after the boards have arrived, built up and tested I will post relevant firmware on this page. Until then!<br />
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* 2011-11-18 Decided to make the top-half a stand-alone project for use with other projects if required. See [[Mcu 0062-LCD-48x84-RC-Enclosure-top-pcb]].<br />
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* 2011-11-13 Practically finalised the design for the top-half pcb with the LCD and buttons<br />
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* 2011-11-03 Did up a design in diptrace for the RC Enclosure internals.<br />
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* 2011-10-01 Got the DS1820 one-wire code working on ATtiny85<br />
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==Schematic==<br />
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This project is designed to fit in the enclosure's bottom half (with battery compartment).<br />
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[[File:0050-sch-v1.0.JPG|thumb|none]]<br />
View schematic as pdf (Nov 2011) [[File:0050-sch-v1.0.pdf]]<br />
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==Circuit Board==<br />
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Bottom pcb with the mcu, eeprom, isp header and the on-board temperature sensor. Please note that these are not yet finished designs but I expect to be 90% there. One of the things I haven't tested yet is the clearance between the top and bottom pcb's once fitted inside the enclosure and see if it clashes with certain components.<br />
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[[File:0050-pcb-3d-v1.0.jpg|220px|none]]<br />
The pcb for the bottom-half of the enclosure. <br />
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[[File:0050-pcb-v1.0.jpg|220px|none]]<br />
see-through model of the bottom pcb.<br />
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Gerbers: [[File:0050-gerbers-v1.0.zip]]<br />
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==Software==<br />
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Latest source code: [[Image:Mcu 0050 tempsensor 20110601.tar.gz]]<br />
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==Release Notes==<br />
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==Gallery==<br />
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==External Links==<br />
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http://www.jaycar.com.au/productView.asp?ID=HB5610&form=CAT2&SUBCATID=986#1<br />
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http://www.atmel.com/avr/</div>Admin