Semtech's LoRa (Long Range)

manuka

Senior Member
Happy to report as suitable offerings catch my eye,although the field is rather a moving target!

The gotcha on competitive price can be P&P &/or bulk order discounts of course. Swish bulky antenna & gold plated sockets can significantly hike costs too, especially if shipped to exotic addresses. In contrast, as I've often mentioned before, we've a NZ-China free trade agreement here that makes for cheap & rapid down under ordering. (This works both ways - NZ's food & beverage sales to China are enormous)

Many of these Chinese modules seem badge engineered, & config. utilities may work on different makers offerings. Hence this WT-800 (which sports well produced data sheets) may be akin to Dorji's.

EXTRA: Microchips RN2483 LoRa™ module may well be the best approach however, especially in EU/UK/USA markets. It's at the heart of this new French HidnSeek .

Stan.
 

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srnet

Senior Member
So if you had some Dorji LoRa UART modules, and its just not convienient to remove them from your application and use the PC application to set them up, what are the PICAXE commands to setup the device for say 434.400Mhz, Bandwidth 62.5khz and Spreading factor 8 ?

I did look in the data sheet but it was not obvious.
 

Hooter

Senior Member
Odd how the module on page 7 of the WT-800T data sheet showing the programming utility is the Dorji module and identical that in the dorji manual - just sayin'
 

srnet

Senior Member
Microchips RN2483 LoRa™ module may well be the best approach however, especially in EU/UK/USA markets.
Seems to be one of the very few to take ease of use (of a UART style module) seriously, the interface commands are relativly understandable.

Whilst providing a PC application to configure a UART device is often promoted as a good thing, both with LoRa and other UART modems, it does suggest that the base module is difficult to program.

If your front ending a RF device with another Microcontroller, why not program it so that the commands to drive it are easy to understand ?
 

manuka

Senior Member
srnet: I certainly concur that config. can be cussedly cryptic! It's somewhat akin to Wordstar (the popular WYSIWYG but pre GUI early-mid 1980s CP/M & DOS word processing program),which used the likes of ^B to start (& end) bold or ^Y for italics. Argh!

Best grit your teeth & check Andrew's embedded PICAXE Dorji DRF1278DM config. code approach below.

FWIW: This advert states such recent LoRa™ modules as the WT-800 are pleasingly AT friendly. However inspection of the WT-800 data sheets ( P.11) implies "AT" is used loosely & that config. is still Dorji style.
 

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MFB

Senior Member
Thanks Stan, my teeth are well and cruelly gritted. Thankfully Robert Rozee has shown there are more convenient ways to set up an RF transceivers module and, as Stuart states, why not make it possible to to this from the host microcontroller (as an alternative to the PC). No problem in providing such libraries for LoRa, just needs someone much smarter than me.
 

srnet

Senior Member
srnet: I certainly concur that config. can be cussedly cryptic! It's somewhat akin to Wordstar (the popular WYSIWYG but pre GUI early-mid 1980s CP/M & DOS word processing program),which used the likes of ^B to start (& end) bold or ^Y for italics. Argh!

Best grit your teeth & check Andrew's embedded PICAXE Dorji DRF1278DM config. code approach below.

FWIW: This advert states such recent LoRa™ modules as the WT-800 are pleasingly AT friendly. However inspection of the WT-800 data sheets ( P.11) implies "AT" is used loosely & that config. is still Dorji style.
No need and too much brain hurt, if I wanted to use a PICAXE to do some reducing power testing I would use one of my own modem modules, which replaces this;

serout 4,T2400,($AF,$AF,$00,$00,$AF,$80,$01,$0C,$02,$00,$6C,$80,$12,$09,$00,$07,$00,$00,$00,$02,$AC,$0D,$0A)

with this;

serout 4,T2400,("SP2",CR) 'SP = Set Power

And you can guess what the command for power level 17 will be ..........
 

manuka

Senior Member
Yes- code refining certainly possible! The tedious approach above was intended more as a expansion of Dorji's data sheets. Typo on that "power level 17" - did you mean just 07 ?

I personally also prefer Microchip's well priced (~US$15) RN2483 & consider it presently perhaps THE LoRa™ module for the masses. Check the "hats off" pix below & note (thanks to an Arduino offering) that only a few connections are needed for simple serial work. Stan.
 

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srnet

Senior Member
Typo on that "power level 17" - did you mean just 07 ?
No typo.

The SX1278, the heart of most LoRa modules can be set (on most modules) from 2dBm to 17dBm, so on all the software I have written the power level can be set directly in dBm, the obvious way to do it really.

I know Dorji did a conversion table;

1=4dBm, 2=7dBm , 3=10dBm, 4=13dBm, 5=14dBm, 6=17 dBm, 7=20dBm

Which is a perverse way to do it IMHO.
 

manuka

Senior Member
Aha - dBm it is! To add to the confusion we've NZ Radio Regs. that insist on using dBW for TX power levels. Hence the Aus/NZ legal power limit on 433 MHz is -16 dBW = 25 mW = 13.97 dBm (= Dorji's "5").

But enough of this banter. Here's news, presently woefully short on technical details, of a prize winning Mexican poverty combating LoRa™ based "Nodi" project.
 

premelec

Senior Member
That's a nice project... and hopefully eventually we'll have something from RevEd... i didn't know you southerners used dbW... that's quite an opportunity to misread specs!
 

manuka

Senior Member
i didn't know you southerners used dbW...
We normally don't (aside from NZ radio reg. cussedness), as mW & dBm far better suit in most applications.
Ah - I assume you realise that NZ means South Pacific New Zealand rather than AZ (Arizona !) ?

Details on the Mexican "Nodi" LoRa™ project elusive. AFAIK the Spanish for "node" is "nodo", but even Googling that variation didn't help.

Perhaps "Nodi" is akin to the well known VHF "Gotenna" smartphone-BT-module non cellular txt approach? LoRa™ ranges should be a near order of magnitude greater than the US$200 Gotenna's, meaning km-10's of km coverage. Reliability, security (both of data - & equipment!), weather proofing, antenna & system cost may be issues ...

As their 1 million Mexican peso prize translates to ~US$50,000, one would expect a decently concrete account rather than hype. Anyone in that region have technical insights ? Stan.
 

manuka

Senior Member
Yes-certainly a touch of hype! 10 days later (& distracted by a midwinter break),further sleuthing shows this -

The 1-million-peso first prize, which went to a team from Guanajuato called Brainiacs. The winning proposal was called Nodi, a free, text-based communications service intended to overcome connectivity shortcomings in remote communities.

The Brainiacs team will also receive some expert advice in the set-up and operation of their budding new company.

“We had been raising funds for a year but [money] was running out. It was then that we decided to risk it all at the Campus Party,” explained team leader Javier Dávila.

The Brainiacs team had been engaged in designing internet-connected sensors and was just a step away from figuring out how to apply their knowledge to help combat poverty.

The result was a cheap and easy-to-use service based on viper text, whose strongest point, said Dávila, “is that it’s based on a free frequency . . . we’re saving in connectivity. [The device] can also have a solar panel on its back, enabling communication and education for the people.”

The device has possibilities in health, education, public safety, communications, financial inclusion and environmental protection, among many other activities that promote employment and income generation.

The prize money represents the first step for the programmers because “in the hardware industry it’s a small amount . . . we can spend up to 300,000 pesos just in initial prototypes. It’s not a lot but it’ll help us take off.”
That "viper" mention seems a typo, & it's likely they used the popular Android VIBER mobile messaging app, with Bluetooth linking to the LoRa™ circuitry. I'd considered much this approach myself using BLE- perhaps time to put up my hand for some of their "financial inclusion"...

Stan.
 

manuka

Senior Member
Steliosm: Thanks for that Nodi web link & pix! Sadly there's little new technically however...

Although maybe using a "free" cell band (800-900 MHz ?) their project of course was hailed as LoRa™ based. Aside from larger antenna issues (& if local TX power etc regs. had allowed),they'd probably have got better rural terrain penetration at lower (VHF ?) freqs.

Nodi somewhat reminds me (yes- long memory !) of the eventually ill fated Frequency Hopping Spread Spectrum (FHSS) 900 MHz Metricom Ricochet. Ricochet's ranges were only a few miles, but in the mid-late 1990s it briefly shone in the USA. This era predated 2.4GHz WiFi, mobile phone wireless data - & even USB...

FWIW: The superior propagation punch of lower freqs. is being recognised by UK's OFCOM,and - along with other spectrum usage factors - they're soon to open IoT bands between 50 & 80 MHz. These days such frequencies are almost DC !

Stan.
 

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manuka

Senior Member
Taiwanese firm Acsip have just released "the world's smallest" (13mm x 11mm x 1.1mm) LoRa™ modules. That tiny footprint is akin to a finger nail sized 8 contact microSD card -it's hard to credit that the crystals are also within that 1.1mm !

There's both a 433-470 MHz S78S and a 800-900 MHz S76S. They feature inbuilt SX1278/6 LoRa™ + STM32L073x MCU. Prices apparently US$18-20 (a pair ?).

Although only a limited number of connections need be made, the 16 x 20 (72 point) LGA (Land Grid Array) profile has daunting sub mm spacings that'll prevent easy soldering... Fewer point LGA adapters are available, but they're apparently not yet LGA-72. Any thoughts ?

Acsip also offer larger LoRaWAN modules =>http://makerpro.cc/wp-content/uploads/2016/07/Acsip-Lora-modules.jpg.
Useful LoRa links here =>https://stockhard.wordpress.com/2016/06/20/hardware-for-the-things-networklora-wan/
 

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manuka

Senior Member
Semtech announce new LoRa modules. (Press Release - Jan. 8th 2018 )

Three new devices,SX1262 (+22dBm),SX1261(+15dBm)& SX1268 (+22dBm), China frequency bands) are currently sampling to lead customers and partners and will be available in full production in late Q1 2018. Development kits for various regions and associated software will also be available at that time. For more information, visit => www.semtech.com/iot.

LoRa SX126x new features:

50% less power in receive mode (~4mA draw)

Extended range with 22dBm transmit power (SX1262)

A 45% reduction in size: 4mm by 4mm

Global continuous frequency coverage: 150-960MHz

Simplified user interface with implementation of commands

New spreading factor of SF5 to support dense networks

Protocol compatible with existing deployed LoRaWAN networks
These look worth waiting for if you intend a LoRa project ! Stan.

Extra: Ver 1.1 of the 107 page (!) manual => https://www.semtech.com/uploads/documents/DS_SX1261-2_V1.1.pdf
 
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manuka

Senior Member
LoRa aloft - and about time! High altitude balloon trials run some years ago by SRNET showed ranges of many 100s of km using just 10mW 433 MHz LoRa transmitters.

Similar open ocean satellite based monitoring- known as S-AIS - is already available for the marine VHF collision avoidance Automatic Identification System.

Marine Traffic has probably the best known live global AIS tracker.They may charge $ for access, but there're numerous free sites suiting shore side vessel monitoring.

Note: Even coastal AIS uses far more powerful vessel transmitters than IoT's flea power.
 
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manuka

Senior Member
Heads up for UART, breadboard & -especially- AT command friendly REYAX (Taiwanese) RYLR8xx/40x LoRa modules. Cost ~US $15 each from the usual online outlets. I've yet to come to grips with them, but good reports have emerged - Google & Youtube. Stan.
 

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