Hi, I have to set up an experiment of Visible Light Communication system in which the transmitter is LED and the receiver is smartphone camera. I just have knowledge about networking and programming. So right now I have no idea how to build a circuit to make the LED blink to represent 0 and 1 bits. I'm reading the book "The art of electronics" by Paul Horowitz and Winfield Hill. While this book is not so difficult to read, I feel that it goes too deep into electronic. Honestly I don't know what I need to study to build the circuit I want. I just feel that I need to know how the logic gates (e.g. DDL, TTL, MOS FET) operate. How to connect them in one circuit. Maybe it'll be too hard for me to make the entire circuit from the scratch. I heard that I can use some existing integrated circuit which I can do some programming with it. For example these chips will generate rectangle pulses and I just need to connect the LED to the output of the chips to get the output light blinking. So the next question is how to know the rule of making the circuit with these chips. And how to program the chip to generate the desired pulse. I know I cannot get the answer in this forum. I just hope you can give me some advice based on your experiences. What is the shortest way for me to make the circuit I want. The book I mentioned above might be great but it doesn't say anything about the chip programming. Is there any book focusing on the part I need to know (logic gates, some basic chips, making circuit from chips, programming with them)?