Communicating with TSL202R
Last time I talked about my USB device that I’m creating. I’ve connected the TSL202R Linear Array Photodiode sensor. It has 128 photodiodes(pixels) that tells us how much light there is on each one of them. This is very useful. It can be used for example for OCR, measuring the angle of a light source etc. I’m interesting in measuring the dimensions of object. It’s actually a simple method. Take a look at this figure:
We have a source of light then an optic system and the sensor. When we put an object in front of the light we get his shadow on the sensor. By measuring the size of the shadow we can calculate the size of the object.
Here’s how the sensor looks like and a simple result of it’s output in my application:
USB HID Device
This weekend I've managed to create my first USB device. It's a simple board with the PIC18F4550 microcontroller. It gets detected from Windows as HID device and works properly. I can send data to it and read information back. Tried the ADC and it works fine. I still have to make some test on the speed of the transfer but for my needs it's more than enough. I used the Microchip USB Bootloader and modified it a bit to work with the free version of C18 compiler. And so the device is able to update/program it's firmware/memory using the PC thought USB. So no need for my programmer for now. There is a design fault in the pictures below. The big capacitor over there under the LED is too big and the device was not working properly. I have now changed it with a 100nF capacitor and everything is fine.
So here are some pics:
