LoRa modules (AI Thinker Ra-01, SX1278)

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mrburnette
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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by mrburnette » Wed Nov 15, 2017 1:30 pm

RogerClark wrote:
Tue Nov 14, 2017 11:41 pm
Ray

Are you sending LoRaWAN packets or raw ones.
<...>
Roger,

For the test yesterday, I was just sending raw packets with no real content. The send program is very similar to this example from sandeepmistry

snippet

Code: Select all

  
  LoRa.beginPacket();
  LoRa.endPacket();

Ray

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RogerClark
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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by RogerClark » Wed Nov 15, 2017 7:28 pm

Hi Ray

Thats basically what I did.

I was hoping to connect my Ublox LEA 6H GPS module to a BluePill and walk around the neighbour sending the position, and leaving a receiving node running at home, printing out the packets to the serial terminal on the PC.
So I could plot some sort if range map.

But It took hours to get the GPS to output NMEA on its UART port, because by default it sends UBX format which none of the decoder libraries I found, seemed to be able to understand.

In the end I found that I had to connect the GPS via its USB connection to the PC and run the Ublox PC software, and go into multiple config screens to enable each individual NMEA message type on the UART port ( talk about over complicated ...)

So I ran out if time to do any range testing :-(


I have some contacts about 50km away, on the other side of Port Philip bay, who are also testing LoRa, so I am going to buy a $5 kids kite from KMart today, so that I can experiment with putting a LoRa beacon at 300ft agl.

I have some small 300mAH lipo cells from a quad copter, which should supply enough power for testing with a BluePill, but I think an ESP8266 etc would be too power hungry.

I was intending to possibly make a repeater using either 1 or 2 LoRa modules, e.g. listen on one freq and resend any data heard, on a different frequency.

Initially I will just use the same module, and will not be listening while retransmitting the data, but using a platform like a kite etc and using one module on 915mhz and another on 433Mhz, plus physical separation on the kite of about 1m, hopefully the transmitter will not desensitise the receiver too much.

I note, that the SX1278 does not operate on 915MHz, so I am likely to use 433MHz and 144Mhz as I have a Ham Radio licence and can use 144 to 148Mhz as well as a wider range on 430MHz

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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by RogerClark » Thu Nov 16, 2017 10:48 am

Only slightly related...

But I thought I'd try to build a airborne LoRa repeater, consisting of 2 of these LoRa modules connected to a Blue Pill and a 300mAH LiPo battery from a mini drone..... which could be flown on a kite.

I bought a $8 AUD kite from KMart this lunchtime, but when I got it home it was far smaller than the packet in which it was sold, and it will not be suitable for anything.

So I think I'm going to need to build a kite.

The best design seems to be a variation on a box kite, known as the French Military Kite or Rescue kite.

http://www.qsl.net/g4vgo/more_kites.htm

Or possibly a Delta box kite

http://www.kiteplans.org/planos/boxdelta/boxdelta.html

I know I can buy kites on eBay etc, they tend to be fairly small, or crazy expensive ...

Kite fabric is not that expensive, around $6 AUD per square metre (£ 3.50 UKP, $4.50 USD), so 2 or 3 square metres and some wooden dowels is going to end up far cheaper than buying a kite and waiting weeks for it to arrive.

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mrburnette
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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by mrburnette » Thu Nov 16, 2017 10:55 pm

... unbeknownst to the forum, Roger is really Kite Man. Be afraid.

Image

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RogerClark
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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by RogerClark » Thu Nov 16, 2017 10:57 pm

Well, that about sums up the kite from KMart.

I thought I was getting a deal at $9 AUD ($6 USD) but I was wrong.

Edit.

Ray you changed the picture ....




BTW. I used to do a lot of kite flying as a kid, and we had one of these RAF rescue kites from military surplus

https://www.google.com/search?tbm=isch& ... ST6l1Q1IKk

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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by mrburnette » Thu Nov 16, 2017 11:06 pm

RogerClark wrote:
Thu Nov 16, 2017 10:57 pm
Ray you changed the picture ....
<...>
Yes, the first kid flying kite was simply too large. Plus, the current one is an "avenger" and reminds me of something .... but I'm old and feeble and can not remember :lol:

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Re: LoRa modules (AI Thinker Ra-01, SX1278)

Post by RogerClark » Thu Nov 16, 2017 11:10 pm

No worries

I liked the big picture ;-)

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