Previous in Forum: 5G Network   Next in Forum: Radiation from hand held electronic devices
Close
Close
Close
4 comments
Rate Comments: Nested
Participant

Join Date: Jul 2020
Posts: 2

Project feedback - LORA + GPS chip recommendations (not LoRAWAN)

07/01/2020 5:43 PM

Hi all

I am developing a product for commercial use (hopefully) and wanted recommendations on some LoRA and GPS chips. The main criterias I have are the chips must consume minimal power (a deep sleep mode is also required), be cost effective and be available in a break out such that I can experiment with them.

The system architecture will consist of a base unit which can communicate to a series of nodes, containing the LoRA tranceivers (simultaneously) and GPS chips. I am new to LoRA but like the fact that it has a range of up to 10-15km.

For the nodes, so far I have been reading up alot on the SEMTECH SX1279 LoRA tranceiver and Ublox NEO-M9N GPS. The intent will be to use ceramic PCB mounted antennas for both chips with a PIC MCU.

For the base unit, again I will be using a PIC MCU and ceramic mounted antenna (for LoRA). Unsure of what chips to use in order to communicate with many different LoRA nodes.

For prototyping purposes, I require either DIP package chips or ones on prefab'd breakout boards.

1. Are these chips recommended for commercial use? Has anyone had any experience with them and can list any drawbacks?

2. I am finding it difficult to find the SX1279 in a breakout with a schematic diagram. Does anyone know of one?

3. The Ublox is fairly expensive at about $15 USD (even in mass production). Does anyone know of an alternative fit for commercial use? If so, do you know of a break out?

4. Which LoRA chip do you recommend for the base unit ?

Thanks

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33392
Good Answers: 1817
#1

Re: Project feedback - LORA + GPS chip recommendations (not LoRAWAN)

07/01/2020 6:08 PM
__________________
All living things seek to control their own destiny....this is the purpose of life
Register to Reply
Participant

Join Date: Jul 2020
Posts: 2
#2
In reply to #1

Re: Project feedback - LORA + GPS chip recommendations (not LoRAWAN)

07/01/2020 8:26 PM

Thanks for the response, but the LR1110 chip needs semtechs cloud back end to processing co-ordinates. I'm after a standalone chip that can provide the GPS coordinates.

The SX1276 is something I've been looking at along with the SX1261 (newer family), but this is on the tranceiver end.

Not sure what to use for the gateway.

Register to Reply
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33392
Good Answers: 1817
#3
In reply to #2

Re: Project feedback - LORA + GPS chip recommendations (not LoRAWAN)

07/01/2020 10:45 PM
__________________
All living things seek to control their own destiny....this is the purpose of life
Register to Reply
Active Contributor

Join Date: Apr 2018
Posts: 21
#4
In reply to #2

Re: Project feedback - LORA + GPS chip recommendations (not LoRAWAN)

07/03/2020 3:16 PM

Currently .. there is no really low power solution (assuming we are talking less the 10 uA during the location calculations)

However you can provide your own "back end processing" for the GPS coordinate extraction. The Source code is available.

This could reside in your application that is communicating with the LoRa node.

Or

Your own resources located else where on the network. (private or public)

The implication being: this location processing is occurring where there is ample power available.

The primary value being brought forth by this solution .. is eliminating the power consumption required for performing the required calculations at the location with the least power available (the remote node).

At the present .. Even the most power efficient GPS (GNSS) solutions require 10s of milliamps for 20-60 seconds to calculate a location "solution".

These solutions do have very low (low uA, even in the nA range) idle and reception power requirements.

When using this type of solution the primary trade off will be:

- how often you are required to report location VS battery life.

Of course, this trade off occurs with the radio (LoRa) also, but generally with shorter duration high power (mA draw rates).

No way around it.. calculating coordinates on the remote node is a substantial consideration in obtaining long (years or even months) battery life.

I recommend use of a accel IC in conjunction with GNSS receiver.. to know when a new location is likely needed to be reported.

Register to Reply
Register to Reply 4 comments
Copy to Clipboard

Users who posted comments:

John L (1); rfwifi123 (1); SolarEagle (2)

Previous in Forum: 5G Network   Next in Forum: Radiation from hand held electronic devices

Advertisement