💬 FOTA (Wireless Programming)

  • @scalz thanks will give it ago.

  • Hi there. For what I'm reading, the MYSBootloader allways uses the default channel 76. Is that correct? It would be a very important addition to this howto.

  • Mod

    @guillermo-schimmel not always, but by default. To change the channel, the bootloader must be recompiled. I have added a note to the howto. Could you check if the information is sufficiently clear?

  • I recompiled MYSBootloader 1.3 with the RF Channel I use and it's now working. I can confirm that FOTA works great over MQTT gateway.

  • @mfalkvidd Thank you as usual.

    I can confirm that is indeed working by recompiling to my channel.

    I have however a couple of questions.

    1. When you say "by default", do that means that there is a way of modify that default? If so, how?

    2. This specific node that I'm testing with, have a fixed node id (I use OpenHAB). But with the recompiled bootloader it "knows" which firmware download. Where does it gets from? Is the bootloader accessing the main sketch? Or is the node id info fixed in eeprom.

    3. If the node id info is in eeprom, could we also have the channel there? It would be so great not having to compile the bootloader.

    Thanks a lot, as allways.

  • Mod


    1. Yes. Isn't that exactly what you did when you did this: "I can confirm that is indeed working by recompiling to my channel" ?
    2. I don't know. But I would also guess eeprom.
    3. The bootloader needs to fit into a very small size, so I am not sure if there is room to read the channel from eeprom.

    Maybe @scalz can comment on 2 and 3.

  • @mfalkvidd said in 💬 FOTA (Wireless Programming):


    1. Yes. Isn't that exactly what you did when you did this: "I can confirm that is indeed working by recompiling to my channel" ?

    Definitely yes. And it worked. I meant a non-compiling way, like set some eeprom variable.

    1. I don't know. But I would also guess eeprom.
    2. The bootloader needs to fit into a very small size, so I am not sure if there is room to read the channel from eeprom.

    Maybe @scalz can comment on 2 and 3.

    Please @scalz should you have a little room, this would be a very nice feature to have.

    Thank you both guys.


  • Mod

    I guess the main hurdle would be that while MySensors stores the node id in eeprom today, the nrf channel is not stored in eeprom. Since bootloader and sketch use the same eeprom, there would have to be some sort of agreement on where to store the channel.

  • Hello, I have my MySensors gateway permanently attached to my openhab server (RPI3), but i want to do FOTA uploads from my desktop. How do I do this since MYSController needs to attatch to a gateway? Can i use an other gateway, both with the same address (ID0)? Thanks

  • @mfalkvidd Hello.
    From what I read it is possible to somehow modify the channel for OTA updates, this is also said here.

    But I can not find other info on how to proceed to change the channel .....
    Can you give me some other clarification or link to follow ???

  • @sindrome73 You have to recompile the bootloader.

    It's easier than it seems.

    1. Mirror this repo on some machine with devel tools (I use OpenSUSE)


    1. Edit the file MYSBootloader.c, only the line:

    #define RF24_CHANNEL (76) // RF channel for the sensor net, 0-127; default 76

    1. Run Make

    Probably it's going to need all the set of avr devel tools. Install them according to your distribution instructions.

    1. You are going to get a .hex. That is the bootloader with the new channel. Install it according the standard instructions. I use AVRDUDESS.

    I can confirm that I did this and it's working great.

  • @guillermo-schimmel Thanks for the reply.
    Very useful, but can you tell me more accurately what software to use to recompile after making the change ????
    Maybe some links to the software to download ..... thanks again for the availability

  • @sindrome73 You have to use the Make tool, which is going to call the avr-gcc compiler.

    Have you ever compiled something using command line tools?

    If you don't know what I'm talking about, just tell me your channel and I can compile a bootloader for you.

  • Quick question: Should FOTA work with personalized nodes/gateway?

    If the answer should be yes, then I appear to have a problem…

    As soon as I enable signing and signature requesting, the node will no longer respond to any internal or stream commands (e.g. Request Presentation, Reboot, Firmware, etc.) made via @tekka’s MYSController app. I haven’t tried anything else yet.

    The node still happily sends signed sensor data to the gateway and they ping-pong with heartbeats, etc.

    And as soon as I disable signing and signature requesting, the node will respond to all those same commands, quite happily rebooting, updating the firmware, etc.

    So, am I doing something wrong?

    (MYSController Version: 1.0.0beta, b3316. MySensors Library v2.3.1)

  • @sindrome73 Hi Good evening, and I'm sorry for the delay in the reply.
    As you have never done a Bootloader, if you are kind enough to do it, I thank you.
    The channel I'm using is the "Channel 84" for now I'm using only the 16MHZ Bootloade, but if you want, the others are fine too.
    In addition you can give me some starting point to be able to fill in too ??
    Thanks for your availability, greetings

  • @sindrome73 here you have bootloaders for all the channels.


    They are unchanged from default elsewhere. Only RF CHANNEL.

  • Hello!! And thank you again ......
    A really good job, it's something that was definitely missing ......
    I would suggest to the directors to expand the guide on OTA you better explain the steps to change channels and make a link to your great job !!

    Now if I understand this and the Bootloader that I have to load on my Arduino Pro-Mini, in practice insert in the path of the IDE of Arduino when I make the updates use that channel

    As soon as I can I try them and I'll let you know, in a lot of thanks again ......

  • @acb

    So, I’m answering my own question a little here after digging into the gateway/node logs and code - and so I'm replying to my own post.

    Should FOTA work with personalized nodes/gateway?

    Yes, it should and it does. FOTA (and any other internal commands) works with personalization (signed commands) using the MYSController.

    What doesn’t appear to work is if you’re using smartSleep and asking the MYSController app to trigger sending your internal command upon receiving from the node - in this case, simply a heartbeat from smartSleep.

    Does that make sense?

    So, if I don’t sleep the node, I can issue reboots and other internal commands that are signed, no problem.

    As soon as I switch to using smartSleep(DURATION) instead of wait(DURATION) and ask the MYSController app to trigger sending, for example, an internal reboot command “Upon RX”, then the reboot command never makes it to the node before it goes back to sleep. So the gateway tries to send the queued command, but the node has already gone back to sleep, and so it gets ignored.

    I’ve tried varying the smartSleep duration as well as the MY_SMART_SLEEP_WAIT_DURATION_MS define.

    I haven’t tried varying the MY_SLEEP_TRANSPORT_RECONNECT_TIMEOUT_MS define, but it didn’t immediately appear that this was a transport connection issue.

    It looks like the gateway/node do all their NONCE request/response just fine, but it could be something to do with how all that gets queued and ordered.

    Doesn’t look like it has anything to do with ATC at all, since I’ve tried enabling/disabling on both node and gateway.

    Also doesn’t look like it has anything to do with the new driver, since I’ve tried both the old and the new and get the same behaviour.

    The only difference appears to be the way smartSleep interacts with signed messages.

    I’ll keep digging, but if anyone has any ideas what I might be doing wrong here, I’d appreciate any help or advice.


  • @guillermo-schimmel It was bothering me that I was using a 16MHz compiled bootloader for 8MHz Arduino Pro Mini.

    So I recompiled the bootloader for all the channels and 1MHz, 8MHz and 16MHz.

    I don't know yet if it makes a difference but it seems right.


  • Hi, Can i burn mysbooloder on arduino mega2560?? its to use as a node. i have a node full functional that manage 24 signals, sensors and actuators. Now i want to make it FOTA node Thanks

  • hi, can i use mysbootloder with arduino mega2560? The mega is used as a node that manage 24 sensors / actuators, i use this by the number of pins needed. thnks

  • @mmanzanelli I don't think you can, the Mega has a different memory structure not supported by the present bootloaders.

  • I have a quick question. so I don´t screw things up more than necessary, What bootloader should I use on a barebone 328p? ... I was just going to burn the "mini pro" that ´@Guillermo Schimmel so kindly uploaded on GitHub. but then I realised ..that might be wrong ..
    Can anyone guide me about what to burn in, I am making a bunch of" 2AA Slim-nodes"

    Also I ahve 3 old ones, I actually don´t remember but If I understood things correct, the Channel have to be the same on all nodes on the network I assume , and by default it is set to Channel 76, unless manually changed in the "old" code before this FOTA-generation?

    I think I read too much info so my mind is slightly confused now 😃 so I hope it was clear enough

  • @badmannen 76 is the default. I uploaded different versions for all the channel numbers.

    Have in mind that they all have to match (gateway and all the nodes).

    If they don't match they aren't going to see each other.

  • @guillermo-schimmel
    Ok so If I push this one "MYSBootloader.ch76.8000000L.RF24_PA_LOW.hex" into the FLASH on my barebone 328P via AVRDudess
    It should , in theory at least , do the trick ?

    And then After I can upload any sketch on top of it, in the Arduino IDE, with just choosing "Programmer-----> USBasp"
    which is what I use to connect to the 328P

  • @badmannen

    1st: In order to upload soft using a cable, you don't need to modify the bootloader. Any bootloader will work.

    if and only if you want to experiment with FOTA (uploading firmware via wireless), then:

    2nd: if you want to use FOTA and you choose MYSBOOTLOADER, then please check the fuses and lock bits, I dont remember them all. But it seems ok, have a try and let us know!

  • @guillermo-schimmel OR Am I making things more complicated than I need? ... maybe it is easier just to copy your hexfile into -->
    "ARDUINO_PATH" > hardware > arduino > avr > bootloaders

    and then burn it in the Arduino IDE ?

  • @badmannen are you sure that your arduino doesn't have a bootloader? why are you trying to modify it?

    If it doesn't have a bootloader, or if you want to play with FOTA, then what you are doing it's ok, that is the way I did it.

  • @guillermo-schimmel
    Ok Perfect! , I will give it a go and see what happens . thanks a lot .. I just needed a little confidence boost to get going 😃

    Yes I wanted to Try to Use FOTA, just to check it out , at least it´s enabled if I push this bootloader in from the start

  • @guillermo-schimmel Thanks a lot ! I got it all up and running node a couple of nodes. But now I confused myself . I got an Arduino Nano as a node that also acts as a repeater, what bootloader can I push into that one? I assume anycahnnel and 16MHz should do the trick since it got that crystal attached.

    And also one thing that is not really clear in my head, I set the "Fuses&Lock bits" with the AVRDudess for my 328P barebone. But do I really need that? . If I load the bootloader in ARduini IDE for example I specify all those settings in the "board.txt" file. Or is that just to tell the IDE what settings is on the chip ?

    If I clear these two things up I think I got everything sorted now 😃