Custom Project with RFM69HCW Chipset

Sub-GHz
#1

Hiya!

I don’t expect to receive a full answer as this topic is more on the personal project side of things, but I’m attempting to have the RFM69HCW chipset transmit a signal, listen to that signal, and basically repeat the signal so the chip receives what was sent.

I’m very new to OOK and FSK so I’m not totally sure how to get the device to read. I know I’m supposed to go in the OOK direction, but have not had any luck no matter what variable I had changed.

Here’s the little gizmo I had gotten on Adafruit, my desire is to have a string in Hex be transmitted from the device, read in RAW on the Flipper, then when the device is in receiving and or listening mode, to expect that same exact string and use that as a True statement.

I’ve attempted to change the modulation to OOK, attempted to have the device read in RAW, attempted eliminating any headers or sync words, changing the bitrate and frequency deviation, but I can’t seem to get it to read anything. The device is set for 433.92MHz.

Any details on how to get it to read anything from the Flipper device would be most appreciated. Also any advice in general because I really have no idea what I’m doing. This Flipper device is my introduction to the Sub-GHz world and it’s really fascinating, but also quite mind boggling.

Thank you!

#2

Let’s start with the fact that the word in the name “batch” seems to hint that you can only transfer data in batch mode. and it already implies the transmission rate and the preamble and the synchronization word and modulation. if you want to change them in your own image and likeness, you need to work with raw data from the air. and implement the decoder and encoder mechanisms yourself. specifically describe what this is for

#3

also, the numbers 433 indicate that the transmitter operates in the 433 + - range and it is either not possible to rebuild it to work in 315, or when switching, the sensitivity and transmitting ability of the transmitter will be approximately zero. since a different antenna path matching scheme is required for a different frequency range. ask the question correctly and describe your idea not from the side of what exactly you want to get and why, and not from the side here I have this and that and I think I need to do it without understanding how it works and what is needed to get the result you want

#4

Thank you for the response!

I don’t know if what I’m trying to do is possible, still trying to conceptualize this all as a whole.

My project in mind is to setup this device to a string of Neopixels to make a small LED ring that can be programmable. The purpose of the Sub-GHz portion is to act as a variable when I wish to change how the lights display, such as having three settings and to cycle between the three.

My expectation was to create a hash code and be able to repeat that exact hash and create a “True” function that runs in CircuitPython to basically switch modes.

I had attempted to set the device into a more RAW format with OOK but couldn’t really get anything to stick. I’m kinda wondering if my output is incorrect since I’m using that to feedback as input.

When reading through the table, I get confused with the bits portion and the values assigned to them, such as on Page 63 from here: https://cdn-shop.adafruit.com/product-files/3076/RFM69HCW-V1.1.pdf

The default code states:
data_mode = _RegisterBits(_REG_DATA_MOD, offset=5, bits=2)
modulation_type = _RegisterBits(_REG_DATA_MOD, offset=3, bits=2)
modulation_shaping = _RegisterBits(_REG_DATA_MOD, offset=0, bits=2)

These are pointing towards the constant RegDataModul (0x02); I had attempted to change the packet mode to a continuous mode without bit synchronizer,

This is where the assumption of the offset being a part of the Bits table and the bits being to change the Default Value.

It’s okay if there’s no clean cut answer; this is definitely asking a lot for a system I’m not familiar with, let alone deviating significantly from the Flipper device on a Flipper forum, I thought I’d give it a try and see if there’s a pointer that I’m missing out on or if I need to be told, “Research OOK more.” I really appreciate any feedback! :blush:

Thank you!

#5

here there can be only 1 advice if you don’t understand what you want to do, first you need to clearly formulate the terms of reference, and if you don’t understand how it works, you need to start from the basics and not immediately sit on the mountain, there is a very high chance that you will break loose and abandon your idea

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