and was wondering if AFSK modulation could be achieved on Si446x with an MCU, seeing that demodulation is possible. I'd like to use this radio module for AX.25 (Packet radio) and for that I need AFSK 1200baud with 1200Hz and 2400Hz tones. Would that be possible to somehow force the radio to produce a transmission simillar to AFSK that would be properly received by FM receivers?
Discussion Forums
Proprietary
Answered
Answered
Hi Piotr,
I guess, it might be possible to transmit AX.25 packets using EZRadioPRO. We seem to have previous attempts to do that (e.g., see this community post), but I'm not sure of the consequences in those cases. Although, the radio does not support AFSK modulation officially, my opinion is that it can be tested fairly easily: use the normalized AFSK baseband signal on the selected GPIO pin with asynchronous or synchronous (if a gaussian filter is required, configuring the same data rate, what the referred article suggested) direct mode.
Also, it might work in packet mode too, but it is much more complicated to configure and feed the TX FIFO continuously with the oversampled data.
To configure the radio GPIO pins for direct modes follow this article; for more information on how the TX direct modes work see this page.
Si446x AFSK modulation?
Hello. Recently I came across this page:
https://www.silabs.com/community/wireless/proprietary/knowledge-base.entry.html/2016/09/08/afsk_signal_demodula-ahV2
and was wondering if AFSK modulation could be achieved on Si446x with an MCU, seeing that demodulation is possible. I'd like to use this radio module for AX.25 (Packet radio) and for that I need AFSK 1200baud with 1200Hz and 2400Hz tones. Would that be possible to somehow force the radio to produce a transmission simillar to AFSK that would be properly received by FM receivers?
I guess, it might be possible to transmit AX.25 packets using EZRadioPRO. We seem to have previous attempts to do that (e.g., see this community post), but I'm not sure of the consequences in those cases. Although, the radio does not support AFSK modulation officially, my opinion is that it can be tested fairly easily: use the normalized AFSK baseband signal on the selected GPIO pin with asynchronous or synchronous (if a gaussian filter is required, configuring the same data rate, what the referred article suggested) direct mode.
Also, it might work in packet mode too, but it is much more complicated to configure and feed the TX FIFO continuously with the oversampled data.
To configure the radio GPIO pins for direct modes follow this article; for more information on how the TX direct modes work see this page.
Best Regards,
Bence