IR sensors ADC and multiplexing

[shadabahmed]

Yesterday, 03:54 PM
hello every1,

i am working on making a type of a slate using IR lights n sensors..
now what i basically want to do is have IR leds to plot X and Y axis and IR sensors onthe opposite ends to recieve the singals. when i place my finger in between a sensor fails to get the IR signal. now my board is supposed to have 10X10 sensors.... so i want to be able to know which sensor didnt get the IR signal....

plz help me with the process of how i make the connections and supply the digital data to any microcontroller....
thanx...

---------- Post added at 12:06 ---------- Previous post was at 11:57 ----------

incase you have any doubts regarding the question plz let me know...

 

[xxtigerxx]

can you gibe more details?

a shematic and a photo.

what kind of ir sensor are you using?

 

[shadabahmed]

can you gibe more details?

a shematic and a photo.

what kind of ir sensor are you using?

since my project is basically in its planning stage i do not have much of the info...
but i am planning to use either IR leds and IR sensors....(any cheap ones) or normal LEDS and LDR....
the arrangement is like a drawing pad with 20 sensors.... 10 in the x axis and 10 in the y axis.... basically i just want to receive the x and y location via a usb.....
i hope you are getting my point....

 

[ALERTLINKS]

For x,y you need matrix. 10x10=100 sensors(100 pixels). Anlogue readings taken one by one. If 8x8 matrix is used, a port of 8 bits can scan a row if input is processed to be digital logic level( 0,1 ). Scan 8 columns succesively and store in mcu registers. Then process and locate 0s for shadow. The light source is not a beemso put it far away to make shadow more clear or lasers can be used.
Arduino - RowColumnScanning
Scanning Basics - What is a pixel?
https://cache.freescale.com/files/microcontrollers/doc/app_note/AN4244.pdf?fsrch=1&sr=2
**broken link removed**