LOPY to ERA-LORA board communication

[jmarcelino]

@pkilcoyne
If I'm reading their manual correctly I think you may have the wrong frequency on the LoPy:

This means the frequency the LoPy should be set to is: 869850000 + (0 * 125000) + (125000/2) = 869912500

[pkilcoyne]

@jmarcelino Yep, I've tried that, no joy.

If c is anything over 0 the LoPy gives an error saying:

ValueError: frequency 870037500 out of range

[jmarcelino]

@pkilcoyne
Did you also try receiving with the LoPy on the new frequency?

Going over 870Mhz is not allowed in ETSI (Europe), the legal range is 868-870Mhz

I guess with the ERA device to use a higher channel you'd need to lower the base frequency.

[pkilcoyne]

@jmarcelino Yes I tried that. Basically both devices are programmed to transmit every 2 seconds and receive. But they're not receiving anything yet.

[jmarcelino]

@pkilcoyne
They're not transmitting at the same time by any chance?

[pkilcoyne]

@jmarcelino Well I stopped transmitting on the ERA-LORA to see, nothing received. I've emailed LPRS again in regards to the frequency, awaiting their reply.

Thanks again,

Paul

[catalin]

hi @pkilcoyne, did you received any answer from LPRS?
I've understood you still have this problem, right?

[pkilcoyne]

@catalin Hi, sorry for the tardy reply, I didn't see yours til now.

I gave up on getting the two devices to communicate, seems impossible.

Any thoughts?

Thanks,

Paul

[pkilcoyne]

@catalin @jmarcelino I again guys. So I've been playing around with two ERA-LORA modules and two LOPY modules again.

I have the two ERA-LORA modules talking to each other and separately the two LOPYs talking to each other.

Here are the settings on both sets of devices;

Can you think of anything else I might be missing?

Thanks,

Paul

[Eric73]

@pkilcoyne Hello, my two cents about reading your topics,
Basically if two lora module have same center Freq, same SF, same SYNCWORD (0x34 for lorawan and 0x12 for private lora), same coding rate, same IQ (IQ is inverted for lorawan and not inverted for private lora usally) and same HeaderSetup (implicit or explicit) the RX/TX work.

I dont see where with lopy how we can set header mode, so i suppose it's always explicit ?

In ERA-LORA it seem to be the same think (cannot set header mode so may be alway set a explicit?). They use "group ID" term instead of SYNCWORD, and they don't speak about IQ (so it's be supposed to be alway inverted ?)
I suggest you to try inverting IQ in Lopy for RX and TX, set group ID to 12xx in era lora , be careful on how you select frequency on both module and try...may be it's change something.

*I dont speak about header CRC mode setup it's a little bit fuzzy how it work.