Author Topic: How to send larger files over RF69 modules?  (Read 920 times)

sheikhumar

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How to send larger files over RF69 modules?
« on: January 05, 2019, 06:12:17 AM »
Hey guys, just getting started with my first Moteinos, one connected to a RPi running the PiGateway sketch, the other one is connected to a LIS3DH accelerometer and a microSD card module. I am trying to log the accelerometer values at 20Hz and save all those values to the microSD card. After every 5 minutes I need to  transmit the accelerometer values file (~2MB) over the radio to the RPi Gateway.

This here says https://lowpowerlab.com/2013/06/20/rfm69-library/ that I can send only 61 bytes every packet and "Longer packets can easily be achieved by chaining".
I have seen a lot of examples for sending 1 packet at a time and they work great, I could write a loop that reads the file 61 bytes at a time, writes them into a buffer which is sent to the Gateway and waits for an ACK and repeats until EOF is reached. This seems like a waste, the RF69 modules can achieve higher bitrates then this, so my question is basically is how can I transmit this file faster, writing to many packets concurrently and sending them at the same time? Any suggestions on how to go about this would be great, as any examples where people might have already implemented this.

Thanks!

Jason

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Re: How to send larger files over RF69 modules?
« Reply #1 on: January 05, 2019, 10:17:50 AM »
Hello,

I can’t say I have done this yet myself, but have started looking into it doing the same type of thing but for sound data. 

The over the air programming thread talks about transmitting 20kB in a few seconds.  Might be a place for you to start looking, it is a long thread though.
https://lowpowerlab.com/forum/wireless-programming-(aka-ota)/wireless-boot-in-2-5-seconds-high-speed-datastreams/

If someone has any other methods I am interested as well!  Thanks!
« Last Edit: January 05, 2019, 10:22:32 AM by Jason »

TomWS

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Re: How to send larger files over RF69 modules?
« Reply #2 on: January 05, 2019, 10:54:01 AM »
Hello,

I can’t say I have done this yet myself, but have started looking into it doing the same type of thing but for sound data. 

The over the air programming thread talks about transmitting 20kB in a few seconds.  Might be a place for you to start looking, it is a long thread though.
https://lowpowerlab.com/forum/wireless-programming-(aka-ota)/wireless-boot-in-2-5-seconds-high-speed-datastreams/

If someone has any other methods I am interested as well!  Thanks!
I can confirm that the protocol cited in that thread does allow OTA boot in less than 3 seconds for a full 328P image (>32KB with headers).  However, I have not used it to transfer block data.

Tom