Thank you Alan G.
How? I really want to do this. I am lacking in my knowledge of digital signal processing. What software? Once I process the signal how do I get a 1 or 0 out of my old computer? I used to know how to get out a one with C and Basic. How do I get the two software packages talking? I am about ready to turn the detector over to Howard for testing. #5 plastic is straws and bottle caps. They either colored or to small to be detected. I just wanted to do better. I used to do something like this with the 9 pin D connectors on yesterday's computers. I needed a way to stop a serial line printer upon buffer full at my old job in 1995. It was an odd situation with some old but critical PLC's that needed to print to a new serial printer. The system worked fine until the office management installed a LAN printer and took away my old computer and printer. It was a long story the old computer was no longer supported, they said. I objected. We will get rid of the computer when we upgrade the PLC's, I said. It was not an office computer or printer. I was overridden and mad about it. All of the PLC software was on floppies. I transferred the software and wrote a C program to print out the ladder logic. It's been a while and I don't remember all of the details. I was too busy for this but now I had to do something. The Basic program could transmit an ASKI character with all zeros. I don't remember what character this was anymore. This resulted in a zero followed by a string of ones on the output line. It looked something like this 01111111. The ones made a long pulse. The signal did not return to zero between the ones. I filtered the pulse with a resistor and a capacitor. The zero reset the capacitor through a signal diode. The string of all ones produced a high voltage in a detector and turned on an output. This output- was sent to the CTS pin. I could send the string of ASKI characters to the 9 pin D's output with C or Basic. I don't know if I can do this with a USB connector. Perhaps that needs to be my next product. A USB to single digital output. Frank -----Original Message----- From: AlanG <[email protected]> To: vortex-l <[email protected]> Sent: Thu, Feb 27, 2014 6:09 pm Subject: Re: [Vo]:Plastic detector find On 2/27/2014 10:17 AM, [email protected] wrote: #5 Plastic lets the light through in colors. Use a cheap camera sensor and look at the color counts. Assuming the light source is broad-spectrum, the #5 image should have a pretty high range of color delta compared to the others. AlanG "It's only software..."
