Author Topic: Image Transmission with RFM69  (Read 245 times)

Creed17

  • Newbie
  • *
  • Posts: 2
Image Transmission with RFM69
« on: July 16, 2019, 01:40:02 PM »
I'm a complete beginner when it comes to wireless transmission, so bear with me here. So I'm designing an outdoor camera which will take photos (640x480, approx 100kb) and transmit them to the receiver. After doing some research, it seems like RFM69 is the best option for the range I am given. I have a few general questions regarding going this route.

  • Will RFM69 work for my project? Is it capable of transmitting images with that much data?
  • Has anyone done this before? What are some problems I may encounter?
  • If I have multiple transmitters and one receiver, will I have interference if all the transmitters are trying to send at once or is there some sort of queue I could implement?
  • Will handling packet loss be an issue?

Again, I know these questions a bit odd and random. Any help would be much appreciated in understanding how RFM69 works.  Thanks.

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 6022
  • Country: us
    • LowPowerLab
Re: Image Transmission with RFM69
« Reply #1 on: July 16, 2019, 04:32:37 PM »
So ESP won't cut it heh?

It's possible with RFM69 but 100k is a big piece of data for FSK even at maximum bitrate.
It would require streaming - I've done it and others have too, making it possible to stream ~30K in a few seconds.

It's an intricate process to make it all happen fast and efficient.
Also depending on how frequently you actually transmit, it might really push the ISM duty cycle limits, may be entirely illegal in some regions.

Consequently I don't have a library or extension for this.

Creed17

  • Newbie
  • *
  • Posts: 2
Re: Image Transmission with RFM69
« Reply #2 on: July 16, 2019, 07:42:41 PM »
Is it possible for ESP to transmit 1/4 mile through dense woods? I've seen your previous posts with some similar scenarios and was wondering if this had been fully achieved yet. I think I'd be fine for the ISM duty cycle limit as I will only be transmitting up to 8 times per day.

Thanks

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 6022
  • Country: us
    • LowPowerLab
Re: Image Transmission with RFM69
« Reply #3 on: July 17, 2019, 09:19:13 AM »
The ESP? It's wifi, 2.4ghz. I doubt it can go across a hundred meters, let alone with trees in between.
I have not worked with this platform for this very reason and the fact that it's not low power.

jra

  • Jr. Member
  • **
  • Posts: 81
  • Country: us
Re: Image Transmission with RFM69
« Reply #4 on: July 22, 2019, 09:29:24 AM »
If you are in an area with cell service a cellular modem might be a better option.  2G modems are relatively inexpensive and supported by the arduino platform but 2G service (at least in the US) is starting to dry up.

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 6022
  • Country: us
    • LowPowerLab
Re: Image Transmission with RFM69
« Reply #5 on: July 22, 2019, 09:58:11 AM »
Unfortunately even 3G is being phased out.
Use 4G/LTE for any new designs, only downside is they are not well supported/documented + you need a SIM card (monthly fees).

jra

  • Jr. Member
  • **
  • Posts: 81
  • Country: us
Re: Image Transmission with RFM69
« Reply #6 on: July 22, 2019, 10:13:48 AM »
AT&T dropped 2G a couple of years ago and plans on shutting down 3G in 2022.  Verizon is dropping 3G late this year and will be the first domestic carrier to be LTE only.  T-Mobile is still hanging in there with 2G/3G but maybe only for a couple of years.  Going forwards NB-IOT or CAT-M1 are probably going to be the best solutions if you want to use cellular but as you pointed out the associated modems and data plans are still kind of pricey and lacking in support.

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 6022
  • Country: us
    • LowPowerLab
Re: Image Transmission with RFM69
« Reply #7 on: July 22, 2019, 01:12:30 PM »
Yup, I was involved in some work with that and it's just all over the place, the LTE/NB-Iot/CAT-M1 modules that do exist are expensive, unstable, have weird power requirements, no libraries, the antiquated AT command set with variations, overall yuck.
There's iridium but its slow and uber expensive.
LoRaWAN/TTN or even Sigfox is basically non-existent in the US, so you're left with bare LoRa/FSK. I think it can be done with some careful engineering.