Hi all,
First I want to thanks all those who helped me with my previous questions...This is slightly off the micro controller topic but I am sure the gurus here can answer my questions or point me to the right direction ;-)
I am experimenting with a PIC based UART for IR serial communication between two PICs, but I am not sure what carrier frequency to use. I did some search on the internet but couldn't find the answer to my questions:
1. What are the advantage and disadvantage of using 38kHz? 56kHz?
2. Why 38kHz and 56kHz?
3. What factors determine the transmission speed between two PICs communicating via IR serial signal? The clock speed of the crystal? Does higher MHz crystal means higher transmission speed can be achieved?
4. For my experiement, I want to send a single ASCII character (N-7-1)from one PIC via IR to another PIC. The second PIC will then send the received character to a PC via RS232 and then echo the character back to the first PIC as acknowledgement and pause the transmission for a couple seconds. The encoding scheme is similiar to SONY's SIRC: 1-bit is 1.2ms, 0-bit is 0.6ms, a 0.6ms space between pulse and a 2.4ms header. I'd like to experiement with different transmission speed, but I am not sure how to calculate the transmission speed. I am using a 12F629 with a 4MHz ceremic resonator.
5. How do I increase the reliability of this transmission while maintaining a high speed transmission rate?
6. If I want to achieve the highest possible transmission speed, should I use a FIR irDA transceiver like those here? (http://www.vishay.com/ir-transceivers/)
I am using Panasonic PNA4602 and Vishay TSOP1138 IR detectors on the circuits. IR diode is Fairchild QEC113 (940nm, 24 degree emission angle)
Any help or point to the right direction will be greatly appreciated!
Thanks in advance!
Datasheets:
**broken link removed**
**broken link removed**
http://www.fairchildsemi.com/ds/QE/QEC113.pdf
First I want to thanks all those who helped me with my previous questions...This is slightly off the micro controller topic but I am sure the gurus here can answer my questions or point me to the right direction ;-)
I am experimenting with a PIC based UART for IR serial communication between two PICs, but I am not sure what carrier frequency to use. I did some search on the internet but couldn't find the answer to my questions:
1. What are the advantage and disadvantage of using 38kHz? 56kHz?
2. Why 38kHz and 56kHz?
3. What factors determine the transmission speed between two PICs communicating via IR serial signal? The clock speed of the crystal? Does higher MHz crystal means higher transmission speed can be achieved?
4. For my experiement, I want to send a single ASCII character (N-7-1)from one PIC via IR to another PIC. The second PIC will then send the received character to a PC via RS232 and then echo the character back to the first PIC as acknowledgement and pause the transmission for a couple seconds. The encoding scheme is similiar to SONY's SIRC: 1-bit is 1.2ms, 0-bit is 0.6ms, a 0.6ms space between pulse and a 2.4ms header. I'd like to experiement with different transmission speed, but I am not sure how to calculate the transmission speed. I am using a 12F629 with a 4MHz ceremic resonator.
5. How do I increase the reliability of this transmission while maintaining a high speed transmission rate?
6. If I want to achieve the highest possible transmission speed, should I use a FIR irDA transceiver like those here? (http://www.vishay.com/ir-transceivers/)
I am using Panasonic PNA4602 and Vishay TSOP1138 IR detectors on the circuits. IR diode is Fairchild QEC113 (940nm, 24 degree emission angle)
Any help or point to the right direction will be greatly appreciated!
Thanks in advance!
Datasheets:
**broken link removed**
**broken link removed**
http://www.fairchildsemi.com/ds/QE/QEC113.pdf