Hey everyone!
I've been messing around with a pair of XBees trying to get them to transmit data, but I've been sort of unsuccessful. I'm trying to send serial data from a radar detector's LCD screen over to another screen, but I haven't been able to do so successfully.
I have the XBees configured to pass DIO, but it's way too slow... I need them to xmit on the order of 8 MHz... Do you all think that is possible with XBees?
Thanks!
The amount of data that you are transmitting will affect how fast you can transmit the data.
So, what kind of XBees are they (Series 1 or 2/2.5)? How much data are you transmitting? How have you configured the XBees?
? 478MHz Operation
? 1200 m Range - depend on transmitter power supply
? 19200bps transfer rate
? Low cost
? Small and light weight
could ztiz be good?
Thanks for the replies! I'm using a pair of series 1 XBees. The problem I'm running into isn't that they aren't transmitting fast enough, but rather, they aren't sampling fast enough. Looking at the logic analyzer, I get a sample about every 2.5 mSec, where I need one every 10 uSec or so...
Do you think that I can get better results if I have an arduino sample all the inputs really fast and shove the data through a serial link? I'm not worried about the delay between the XBees, as long as all the data gets transmitted.
Well, can't u ask to sample faster with the Arduino Software? (i know it's like the application called :Processing)
have a look a this:
Timing
The Arduino delayMicroseconds() function creates the shortest delay possible from within the Arduino language. The shortest delay possible is about 2 us (microseconds).
For shorter delays use assembly language call 'nop' (no operation). Each 'nop' statement executes in one machine cycle (at 16 MHz) yielding a 62.5 ns (nanosecond) delay.
asm("nop\n\t");
asm("nop\n\t""nop\n\t""nop\n\t""nop\n\t"); \ gang them up like this
from :
http://www.arduino.cc/playground/Main/AVR
Other information :
xbee Series1:
Transfert data speed: 1 200 bits/s
RF Data Rate 250 kbps 250 kbps
xbee pro Series 2:
Transfert data speed: 1 200 bits/s
RF Data Rate 250 kbps 250 kbps
apc220
Transfert data speed: 1 200 to 19 200 bits/s
Baud rate: 1200-19200 bps
Baud rate (air): 1200-19200 bps
Receive Buffer: 256 bytes
Fréquence : 431 à 478 MHz (résonateur de 1 KHz)
Puissance : 20 mW Tension : 3,3 à 5,5 V
Courant : <35 mA à 10 mW
Transfert des données : 1 200 à 19 200 bits/s
Taille du paquet : 512 octets
Température de fonctionnement : -20 °C à 70 °C
Portée : 305 cm (sans obstacle)
Dimensions : 39 mm x 19 mm x 2,8 mm
I hadn't seen that function before... I'll have to try it out and see if it works out. I'm planning to have the 5 I/Os I need to sample connected to the arduino, have it sample each as fast as needed (about every 10 uSec) create a packet, and send it to the XBee to be transmitted.
Now, with that much serial data... do you think it will cause an overflow on the XBee?
i don't know about the xbee but i know the rf apc220, have a buffer in case of overflow...
it's all about testing and testing the limits... but at least get it documented on the forum 
heh
if you want you can post youor arduino program and i can testi it in my setup