RFLink antennas

[ricorico94]

Hi,

I built a RFLink using breadboard and superheterodyne Qiachip WL101 + WL102, each equipped with their small spiraled antenna which I soldered on the small PCBs.
Now, as I notice some missed receptions, I'd like to try the RXB6, but I don't understand the wiring described on the RFLink blog.
1- I should only replace the receiver of Qiachip by the RXB6, correct ? But why isn't taking the same pins that the Qiachip receiver ? (VCC of arduino for the Qiachip versus pin16 of Arduino for the RXB6. Is it correct ?)
2- I don't really understand how to handle the antennas. On the PCB an kit from Nodoshop, I see a single antenna: so do we share the same antenna connected to both antenna pins of receiver and transmitter ? Or is this antenna only used for receiver and we rely on a very small antenna for the transmitter? But on their diagram on the same page, I see 2 antennas logos..
3- in case I want to add 2 other NRF2401 (one for whatever .4GHz signal and one for Milights), how many antennas should I have? 2 antennas (one for 433MHz and one for 2.4GHz, or 3 antennas ? (1x433+2x2.4GHz ?) or even more if need to dissociate receivers and transmitters ?

br,
Eric

[Stuntteam]

1- I should only replace the receiver of Qiachip by the RXB6, correct ? But why isn't taking the same pins that the Qiachip receiver ? (VCC of arduino for the Qiachip versus pin16 of Arduino for the RXB6. Is it correct ?)

You cna use VCC or pin 16, it does not matter that much. VCC is always powered.
RFlink manages pin16 and removes power fro mthe receiver when it is in transmit mode.

2- I don't really understand how to handle the antennas. On the PCB an kit from Nodoshop, I see a single antenna: so do we share the same antenna connected to both antenna pins of receiver and transmitter ? Or is this antenna only used for receiver and we rely on a very small antenna for the transmitter? But on their diagram on the same page, I see 2 antennas logos..

The Aurel module is a transceiver and shares the antenna between the transmitting and receiving part. It Internally handles the antenna selection.
You can not do this with 2 seperate modules unless you add additional hardware to make sure that the signal does not flow in the wrong direction.

3- in case I want to add 2 other NRF2401 (one for whatever .4GHz signal and one for Milights), how many antennas should I have? 2 antennas (one for 433MHz and one for 2.4GHz, or 3 antennas ? (1x433+2x2.4GHz ?) or even more if need to dissociate receivers and transmitters ?

The NRF24 is a transceiver and has 1 antenna that is shared for transmit and receive.
433mhz has its own antenna(s) and you can not share it with 2.4Ghz as every frequency has its own antenna specifications.

If you were to add a second NRF you will have a second 2.4Ghz antenna.

[ricorico94]

Hi,
Thanks a lot for these clarifications ! I could suggest you had them on the RFLink blog, because I think they're really helpful for people like me with some but still little knowledge of electronics.

So, if I understand properly, the PCB & kit sold on Nodoshop is only planned for 1 external antenna (linked to the Aurel for TX+RX). If I want to add 2 NRF2401 on the system, they must be built on separate PCB or on breadboard (maybe the NRF2401 for Nodo can be soldered on their PCB, but not the both Nodo's and Milight's NRF2401. Correct), and on these PCB/Breadboard I could install the 2 extra 2.4 GHz antennas (if I want full sized antennas -is it a good idea ?) Is there a minimum distance between all these antennas ?

br,
Ricorico94