See the RoastLogger website for full details of the current version including screenshots and details of how to download and install.
![Image](http://roastlogger.co.uk/coffee/roastlogger/screenshots/roastlogger-small.png)
This thread covers the development of RoastLogger from the first version, that exclusively read temperature data from the computers display via webcams, to the current version that can provide computer control and accepts temperature input from a range of input devices.
The thread is now rather long making it difficult to find information on a particular input device. To assist in that regard the following table lists some key stages in development when various input/control interfaces where added. The table indicates the page number in this thread and the date of the relevant first post related to the update:
![Image](http://roastlogger.co.uk/coffee/roastlogger/screenshots/inputs-progress.png)
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The initial title for this thread was "The roast logger Heath Robinson would be proud of?" this is referred to in the following post.
Just in case Heath Robinson is not known so well outside the UK: From Wikipedia:
"Heath Robinson" has entered the language (in British usage) as a description of any unnecessarily complex and implausible contraption.
I am posting this in the members area to see if any TMC members wish to give it a try and advise if they think it is suitable for general release.
This started as a bet and a bit of a joke with my son. It was not supposed to be serious, and It may have been more sensible to delay posting this until April 1st next year. But ....... it works! ....... it works very well! ..... Well for me anyway. See the photos below.
My son has recently graduated from Cambridge in Computer Science and is home on holiday before he starts work. I was discussing with him the real difficulty of developing a program to read temperature data from different multi-meters in different operating systems.
I jokingly suggested that it would be easier to use a webcam to display an image of the instruments digital display on the computer and then capture the image in a program that would process the image and use optical character recognition to read the data and log/chart it. I also suggested that this approach would work just as well for roasters with built in temperature displays but no interface to the computer.
My son laughed and said it would be way too difficult. So that was it, it had to be done!
I know this is a really crazy idea and can hardly be described as plug and play but I am now using it to log all my roasts on the Hottop Programmable. It has not missed a beat in several hundred readings.
It will ONLY work from a good clean focused steady webcam image with uniform lighting (no shadows or highlighting in the image). To achieve this the following is ABSOLUTELY ESSENTIAL:-
- Reasonable quality webcam that can be focused at distances of 10 to 40 cm.
- Support bracket to hold the webcam steady in relation to the digital display.
- A small screen (any uniform colour) positioned so that the reflection the webcam sees in the display is of Nothing but the screen. See my circular "shreddies" screen painted matt black and mounted on the camera focusing ring for one solution. I can not emphasise enough that this is essential. If you can see anything in the image other than the digital display it will not work reliably.
So if you have read on to this point without collapsing into fits of laughter, are willing to make the support bracket and screen, would like to play with the beta version and test it in the near future, I will email a copy to the first few people to PM me with their email address. All I ask for in return is feedback on how it works (or doesn't) for you.
The program can read two separate temperature displays simultaneously and log/chart both. It saves logs to comma separated value files suitable for spreadsheet programs. Any previously saved log can be read in to use as a template for the next roast. The program will work on Windows XP, Windows Vista, Linux or OSX (64 bit only for OSX) provided that the Java SE Runtime Environment (JRE) 6 or above is installed. The only other software required is whatever program/drivers you use to display webcam images on your computer.
If people are interested and further testing goes well I will make this generally available for download.
The general arrangement. Note the high tech Shreddies anti reflection screen!
![Image](http://roastlogger.co.uk/coffee/smilestore/ocrroastlogger.jpg)
The layout. The area to capture is placed on the RHS of the screen.
![Image](http://roastlogger.co.uk/coffee/smilestore/overall.jpg)
The captured and processed image. The result must be black characters on white background. The program can invert black to white for reading LED's and can rotate the image 180 degrees if necessary.
![Image](http://roastlogger.co.uk/coffee/smilestore/ocr2.png)
Having captured the image the logger records the results at 5 - 60 second intervals as chosen by the user.
Buttons are provided to record time and temp. at the main roast stages.
![Image](http://roastlogger.co.uk/coffee/smilestore/logger.png)
The log is automatically charted against any previous roast profile. This chart is from a 5 second interval log. The chart is much smother if 30 second or 60 second interval is used.
![Image](http://roastlogger.co.uk/coffee/smilestore/charttab.png)
The program can save the chart as a png file.
![Image](http://roastlogger.co.uk/coffee/smilestore/chart.png)
Any previous profile can be used as a template. The main roast stages of the template are listed for guidance and the profile shown on the chart.
![Image](http://roastlogger.co.uk/coffee/smilestore/template.png)
Alarms can be set as shown.
![Image](http://roastlogger.co.uk/coffee/smilestore/alarms.png)
Webcam capture. Note the uniform background in the area of the temperature display shielded by the screen and the reflections below the screen (above on the image as the camera is upside down).
![Image](http://roastlogger.co.uk/coffee/smilestore/webcam.jpg)