Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: Blood-man on August 10, 2009, 08:02:10 PM

Title: RF reciver
Post by: Blood-man on August 10, 2009, 08:02:10 PM
I found an RF receiver at Digikey http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=694-1005-ND (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=694-1005-ND) for $9.82. Datasheets show 'Data rates up to 115kbps', so I guess it's fine. but it also shows "Receiver operating at the 902-928 MHz band." and "1.2MHz receive bandwidth". Would it be fine for the Atmega168 at my $50 robot??
Title: Re: RF reciver
Post by: Soeren on August 11, 2009, 05:32:54 AM
Hi,

'Data rates up to 115kbps', so I guess it's fine. but it also shows
That's the throughput.


"Receiver operating at the 902-928 MHz band."
The carrier wave is within this band.


and "1.2MHz receive bandwidth".
This is the bandwidth that the signal occupies (i.e. centre frequency +/- 600 kHz)


Would it be fine for the Atmega168 at my $50 robot??
Probably, but without knowing how you wanna use it, it's really hard to say.

Title: Re: RF reciver
Post by: Blood-man on August 11, 2009, 08:11:51 AM
I gonna create one way wireless connection with computer through radio transmitter and receiver. I will connect tx on the ATmega to the transmitter, it will transmit information to the receiver that connected to the TTL to USB adapter, and then  to the computer through the USB to the computer. I'm not sure that frequency of the receiver  would be able to receive data, because in the UART tutorial says that the frequency of the microcontroller got to be 8.00 MHz  ???
Title: Re: RF reciver
Post by: Soeren on August 11, 2009, 03:32:00 PM
Hi,

I gonna create one way wireless connection with computer through radio transmitter and receiver. I will connect tx on the ATmega to the transmitter, it will transmit information to the receiver that connected to the TTL to USB adapter, and then  to the computer through the USB to the computer. I'm not sure that frequency of the receiver  would be able to receive data, because in the UART tutorial says that the frequency of the microcontroller got to be 8.00 MHz  ???
The carrier wave frequency of the radio link (remember to get a matching transmitter as well) has nothing to do with the clock frequency of the controller - the carrier wave frequency is only relevant for the transmitter and the receiver.

I just skimmed the data sheet and discovered that the digikey page is not quite honest... The max. data rate is NOT 115 kbps. The max. data rate of the chip advertised on the page is 1'200 bps (= 1.2 kbps) - look at the "Product Ordering Information" on page 10 of the data sheet for verification should you need it.
Title: Re: RF reciver
Post by: Blood-man on August 11, 2009, 03:38:25 PM
Hi,
Hi,

I gonna create one way wireless connection with computer through radio transmitter and receiver. I will connect tx on the ATmega to the transmitter, it will transmit information to the receiver that connected to the TTL to USB adapter, and then  to the computer through the USB to the computer. I'm not sure that frequency of the receiver  would be able to receive data, because in the UART tutorial says that the frequency of the microcontroller got to be 8.00 MHz  ???
The carrier wave frequency of the radio link (remember to get a matching transmitter as well) has nothing to do with the clock frequency of the controller - the carrier wave frequency is only relevant for the transmitter and the receiver.

I just skimmed the data sheet and discovered that the digikey page is not quite honest... The max. data rate is NOT 115 kbps. The max. data rate of the chip advertised on the page is 1'200 bps (= 1.2 kbps) - look at the "Product Ordering Information" on page 10 of the data sheet for verification should you need it.

Many thanks!!!  ;D