RFM69H initiation problems with Arduino UNO

I have setup a LoRa RFM69H 866MHz chip to my arduino UNO, unfortunately I cannot get the chip to initiate in the code, I'm usingt he sender example from the LoRa library.

I have wired the arduino to the RFM69H as follows:

DIO0 -> 2
RESET -> 9
NSS -> 10
MOSI -> 11
MISO -> 12
SCK -> 13

I soldered a temporar antenna from wire while I wait to get a copper one. But I figure this isn't teh problem.

I have the bare chip only, have tried 3 different chips in case i had burned any soldering and have tried 2 different UNO's with this setup with no luck.

I'm aware the chip is only compatible to 3.3V and have powered the chip accordingly using voltage dividers across the SCK, NSS and MOSI connections.

I have gone through the wiring multiple times and am sure it is done as mentioned. Does anyone know anything I could be doing wrong or any way to further debug this chip?

You need to give precise identification of the library you are using and its version, and your
circuit schematic - for instance are your voltage dividers low enough impedance? Do you have
the correct antenna matching components? (if not I’d be worried about high VSWR trashing the output
device)

Personally I’d never contemplate a bare RF-transceiver chip like this, get one on a breakout with
all the rf matching circuitry prebuilt and tested!

Are your chips known to be genuine?

tdam2112:
I have setup a LoRa RFM69H 866MHz chip to my arduino UNO

Why do you think the RFM69H is a LoRa device ?

tdam2112:
I'm aware the chip is only compatible to 3.3V and have powered the chip accordingly using voltage dividers across the SCK, NSS and MOSI connections.

Use proper level shifters. This may very well be causing problems.

Also indeed RFM69 is not LoRa. That'd be the RFM96. Same frequency but different protocol and they can't talk to each other.

A straight wire for antenna should work fine - as long as it's 8.63 cm long. That length is pretty critical.

wvmarle:
A straight wire for antenna should work fine - as long as it's 8.63 cm long. That length is pretty critical.

I would not disagree that the length is critical for maximum radiated power.

However, these LoRa devices are made from relativly low cost components and as such the actuall output impedance can be expected to vary slightly. The consequence is that the 'critical' length for each individual module can vary slightly.

At least thats what I found when I measured some modules for maximum output, see how radiated power varies with the antenna length, these are 3 LoRa modules at 868Mhz;

The RFM22B modules that I worked previously also exhibited the same issue, the 'correct' antenna length was not always the one that produced maximum output. In some cases trimming the antenna length on each module yielded improvments in the 3dBm region.

Apologies for the lack of information,

the voltage dividers I'm using to regulate the voltage are 1k and 2k, I'm not sure what the current through them is as my multimeter's current readout is broken.

I unfortunately don't have any proper level shifters at hand to test with, might invest in some arduinos pro mini and just do everything through those instead.

I was not aware rfm69 was not a LoRa device, thanks for clearing that up for me, I hope I didn't fry the board by uploading the LoRa protocol on it.

I have placed a wire as an antenna at the recommended 8.63 cm length although, I haven't been able to initialize the chip at all so I haven't been able to check the signal strength and optimized it etc.

I'm currently using the RFM69_LowPowerLab Library examples, and in all of them I cannot get the chip to initialize, I've tried with a couple of chips with no success.

tdam2112:
I hope I didn't fry the board by uploading the LoRa protocol on it.

You cannot 'upload the LoRa protocol' that is contained within the firmware of the Semtech LoRa device itself.

What would happen to the RFM69 device when you give it the wrong set of register writes I doubt anyone knows.

Unless it actually can store user software... likely nothing will happen.

The first for you to do is to establish basic communication with the module(s). It sounds like that part is not working. Use a ready-made RFM69 library, with existing example sketch. That way you can use known good code, and when it can detect the module at least you also know your wiring is correct.

tdam2112:
Apologies for the lack of information,

the voltage dividers I'm using to regulate the voltage are 1k and 2k, I'm not sure what the current through them is as my multimeter's current readout is broken.

probably low enough impedance for the speeds needed, 470/1k might be worth trying.

I unfortunately don't have any proper level shifters at hand to test with, might invest in some arduinos pro mini and just do everything through those instead.

I was not aware rfm69 was not a LoRa device, thanks for clearing that up for me, I hope I didn't fry the board by uploading the LoRa protocol on it.

Since LoRa is proprietry the lack of "LoRa module" in the description is pretty conclusive evidence!
LoRa uses a unique spread-spectrum RF hardware modulation scheme as well as proprietry encoding of
data (though check out google for reverse engineering of this). Most cheap RF transceiver modules support
NBFM and OOK typically, not spread spectrum techniques.

There is no way to upload anything to the chip, it doesn't have firmware, its all hardware.

I have placed a wire as an antenna at the recommended 8.63 cm length although, I haven't been able to initialize the chip at all so I haven't been able to check the signal strength and optimized it etc.

The chip pins need an LC antenna-matching network or you risk frying the device on the higher power
settings with a hopeless VSWR. Have you seen Figure 42 of the datasheet? They recommend separate
matching networks for TX and RX, and external PIN switch and a 5 pole low pass RF filter.

I'm currently using the RFM69_LowPowerLab Library examples, and in all of them I cannot get the chip to initialize, I've tried with a couple of chips with no success.

BTW when you said "chip" in your posting did you mean "chip"? I'm pretty sure you meant module, in which case you've confused me no end...

wvmarle:
Unless it actually can store user software... likely nothing will happen.

The first for you to do is to establish basic communication with the module(s). It sounds like that part is not working. Use a ready-made RFM69 library, with existing example sketch. That way you can use known good code, and when it can detect the module at least you also know your wiring is correct.

I'm currently using the RFM69 Library by RFM69_LowPowerLab with the Struct_Send and Struct_Receive examples. but I'm stil not being able to initiate it.

MarkT:
probably low enough impedance for the speeds needed, 470/1k might be worth trying.Since LoRa is proprietry the lack of "LoRa module" in the description is pretty conclusive evidence!

I have tried reducing the resistances to improve the impedance but it still wasn't able to initiate.

I have purchased some arduino pro minis, maybe I will have better luck with them.