First off, I would like to say Happy New Year everyone! Apparently we all survived after all. Anyway, for the past couple of weeks, I started to mess around with X-Bees wireless modules. First off, what are X-Bees? X-Bees are a special type of chip that allows you communicate microcontrollers and computers together using serial communication.
There was a great deal of frustration when using these chips. First off, I soldered the X-Bees to the wrong side of the breakout board. It took me quite some time for me to realize the soldering mistake. Then I tried running the modules at an 115200 baudrate, which proved to be too much for the wireless module. Finally I got the modules communicating with each other when I programmed the PIC18F4553 to send “Hello World” to the computer. Although I managed to transmit the message wirelessly, the propagation distance was terrible. In fact, I could only get a transmission distance of a 1 foot. I began to wonder why the propagation distance was so low. Then I realized that the X-Bees I brought did not include the necessary antenna needed. After realizing this fluke, I quickly went to Sparkfun and brought the necessary antennas, which will not come in until next week.
The final object I brought was a 74HC4052. What’s so amazing about this chip? It’s actually a multiplexer/de-multiplexer chip designed especially for analog and serial devices. In other words, you can connect up to 8 serial/analog devices using one microcontroller. I did an initial test which I connected my serial LCD to one pin, and the serial port of the computer to the other serial port. It took me some time make the right connections and debugged the hardware, but it worked marvelously afterwards. Overall, I think this chip is amazing! Previously, I was trying to think of a way to connect three of my serial devices using one microcontroller. However, after using chip, this will become a default option for me. In fact, you guys can expect a tutorial on how to use the chip this Friday.
So lately I’ve been messing around with alot of electronic components lately. One of these beauties is a 160×120 LCD screen. I will admit, they seemed a little daunting at first, but I was fairly surprised how easy it is using these LCD screens. From what I’ve seen thus far, special commands are executed by sending the hex value 0x7C followed by the proper command. For example, to reset the display, I just need to send 0x7C then 0x00. Of course, to add text to the display, just send an ASCII message to the display. I did not do anything with boxes or lines yet, but will be part of my agenda.
The last new item I used this week was a RFID ID-120 reader. Like the 160×120 display, it’s controlled via serial. Apparently, this item beauty was shown in Blidr, and the pseudo code for reading the RFID tag was very simple. In fact, I re-wrote the code to be used with the PIC18F4553, which I will post a tutorial on how to use it before I go back to RPI.
The picture above shows the tag of one of the RFID’s after I ran my RFID reader code on the PIC18F4553. It’s a little slow reading the tag at times, but I find it very reliable. Well, that’s it for me this week! See you guys on Monday….o wait. The world is gonna end today. Well, it’s nice knowing you guys!