Hi! This is my first time using an Arduino board, and I need some help with certain things.
I am building a weather balloon that will take pictures, record coordinates, send the coordinates to the ground. The antenna on the ground will receive 50 baud RTTY, transmitted at 434 MHz, but I have a problem. The antenna has a BNC connector that I have no idea how to adapt to a computer. Someone who has been helping me told me that I should use an Arduino board to adapt the signal to be able to go from BNC to the receiver module, then to the computer. How would I go about doing this, is there sample code out there that I can build off of? Thank you!
If there is any more information about my project that you need to help me, please ask!
Hi,
BNC is simply a physical connector. The antenna needs to connect to a 434 Mhz receiver of some type. You may need to adapt the BNC to whatever input connector the receiver has, but that has nothing to do with Arduino.
Once the receiver (and I assume it's RTTY demodulator) is putting out data, THEN you will need to connect that to Arduino or a PC..
Read up on RTTY (Radio Teletype). You need to know stuff like how many data bits per character etc...
There's details to this!!
The receiver receives information at 434 MHz and outputs it as true data ("The data is squared version of the Audio signal on pin 6 and is true data, i.e. as fed to the transmitter"). So do I need an RTTY library for the Arduino (WDHAB: RTTY Library for the Arduino)? Also, the receiver outputs 500mV on the Audio signal pin, which I am assuming is the same voltage for the true data pin. If this is so, is there some way to tell what amount of coax wire I should use as to not diminish the signal too much? I have a 6-foot 50 ohm BNC connector, but I was wondering if this is too long?
I have a 6-foot 50 ohm BNC connector, but I was wondering if this is too long?
That should be fine. Check that the CABLE is 50 ohms.
You need to match whatever baud rate, number of data bits, number of stop bits is used by the sending device. Do you have that information??
RTTY uses Baudot code, which has 5 data bits, 1 stop and one start bit. That is what I am hoping to be able to transmit, but I need to somehow convert the RS-232 output of the GPS device to RTTY format. The library I linked to in my previous post supports "ASCII 7 or 8 bit, 1 or 2 stop bits, 50 or 300 baud speeds and has XOR checksums using USB type transmissions.". Is that what you were asking? :\
Hi,
IsTHere a real need for 5-bit Baudot? If the GPS puts out ASCII why can't you transmit that, at slow baud rate if needed??
I have been told that RTTY works more reliably over long distances, and It wouldn't add any cost to my project for me to do so. I also think that it will be an interesting and useful skill to know for the future as well. So am I on the right track for this? Are there some important things I have yet to do (software-wise) for my project to work?