Messages posted by: Ken Biba

Rick:

We are using the RadioHead library. The question is about programming the wide variety of RH95 encoding modes. Their standard (four) modes for the RH95 work fine, but are not the longest range modes (about 8-10 dB in link budget short). So we have been exploring using the RadioHead library to directly program the configuration registers to get the highest range possible. That seems to work well, but we find a consistent problem with RH95 modes in which our short packets (17 octets of payload) exceed ~1 second of airtime. These VERY long packets should have the best link budget and best processing gain from Semtech's spread spectrum. Should give the very longest range.

For the modes I indicated in the message above, we see problems. That is, we either get no communication, or rather high packet errors.

We have an NDA with Semtech and they tell us to ask the radio module manufacturer. Can you answer the questions or refer us to HopeRF support?

We will share more of the range data as it becomes ready to publish ... but we suspect much longer ranges are possible with the right antennas and equipment location.

Ken

I am building a 900 MHz LoRa system from Miniwireless Anarduino modules and the RadioHead library.

I am looking to test for maximum range with very small packets (17 octets).

I find the system works fine when the total frame airtime is less than 1 second, begins to deteriorate (high packet error rates) when the frame airtime is about 1 second and becomes totally blocked (no packets successfully received) above that.

This seems to be correlated with high spreading codes and narrow bandwidth.

For example: 31.25 KHz @ Sf9 (.85 sec airtime) appears to work fine (as well as many other mode combinations with shorter airtimes).

I begin to see packet errors (50%+?) at 1.1 sec frame airtime (125KHz @Sf12, 62.5KHz @Sf11, 32.25KHz @Sf10). I cannot seem to get communication at 31.25 KHz@Sf12 (4600 msec), 62.5 KHz @Sf12 (2300 msec), 31.25KHz @Sf11 (2640msec). 31.25 KHz@Sf10 (1320msec)seems a bit anomalous - one software does nothing, the other gets a few packets thru.

Any thoughts?

I am building a 900 MHz LoRa system from Miniwireless Anarduino modules and the RadioHead library.

I am looking to test for maximum range with very small packets (17 octets).

I find the system works fine when the total frame airtime is less than 1 second, begins to deteriorate (high packet error rates) when the frame airtime is about 1 second and becomes totally blocked (no packets successfully received) above that.

This seems to be correlated with high spreading codes and narrow bandwidth.

For example: 31.25 KHz @ Sf9 (.85 sec airtime) appears to work fine (as well as many other mode combinations with shorter airtimes).

I begin to see packet errors (50%+?) at 1.1 sec frame airtime (125KHz @Sf12, 62.5KHz @Sf11, 32.25KHz @Sf10). I cannot seem to get communication at 31.25 KHz@Sf12 (4600 msec), 62.5 KHz @Sf12 (2300 msec), 31.25KHz @Sf11 (2640msec). 31.25 KHz@Sf10 (1320msec)seems a bit anomalous - one software does nothing, the other gets a few packets thru.

Any thoughts?

Different antennas for receive and transmit ... looking at very long range.

Just noticed the sensor ... but there are no specs for pressure/altitude range.

Ken

It appears that the LoRa radio module supports separate Rx and Tx antennas.

Can this be supported on the Anarduino+LoRa module?

Ken