[argyllcms] how to connect a home made colorimeter to ArgyllCMS?

  • From: "Tom" <chiataimakro@xxxxxx>
  • To: "argyllcms" <argyllcms@xxxxxxxxxxxxx>
  • Date: Mon, 18 Aug 2014 03:54:36 +0800


i am a student studying engineering at South China Agricultural University. i 
read a lot about CMS, both online and in libraries. I own a Huey and been using 
it with dispcalGUI/ArgyllCMS. of course i was shocked by it's speed and 
accuracy(to be honest, either was i out of luck, or be Huey has nothing to do 
with accuracy. a decomposition shows plastic film filters stacked together). 
later i purchased an i1 pro.
personally i d like to thanks Mr. Gill for his brilliant work on opensource 
color management software.

now i am designing a colorimeter, as a hobby work, with a TCS34725 color light 
sensor from AMS(former TAOS). constant current led drive is implemented to 
provide stable illumination(even though it's a bad idea to use a colorimeter to 
measure the characteristics of reflective materials).

the schematic work is partly done. well some decisions have to be made:

1) how can that little thing talk to argyllcms? i plan to use a USB-TTL chip 
for communications(native USB increase costs and complexes the software). it 
will open up a serial connection on windows, and return RGB measurement values 
on request. i can write an exe to communicate thru serial in .NET, but how 
could argyll make use of my exe? does argyll have some kind of measure to 
communicate with colorimetry devices that are not directly supported by the 
binaries? like loading a custom dll, or making a tcp request to some port? or 
do i have to provide you with a datasheet of the device, and the device itself, 
in order to let you write some code about it?

i am not very familiar with native windows C programming(with serial 
communication and all those api stuff), nor do i have much experience to code 
in a pro style like argyll. for me it could be a fun of trial and error, or it 
could be a waste of time.

2) what USB-TTL(serial) chip should i choose, to avoid trouble for linux users?
i myself is a dedicated windows user. but i want my work to be useful for 
everyone. here in china a lot of options are available:

FTDI FT232 : stable, known to work with linux, expensive
Prolific PL2303 : full of fake chips, known to work with linux, extremely 
cheap, limited speed(115200 baud rate max).
WCH CH-340 : Chinese Mainland brand, Windows driver provided, extremely cheap, 
easy to solder package(SOP16), 1M baud rate stable.

3) a question: if the filters built inside an RGB sensor have exactly the same 
spectrum sensitivity characteristics to the LMS sensitivities of human eye, can 
i obtain accurate XYZ readings from it?

Greetings from far east,
Qin Yongliang

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