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Hi,
i would like to Flash the Jeenode with Arduino over a Bluetooth Serial Device. I connected the BT Module with the Jeenode and can see the Serial Output in my Terminal. So this works fine. I connected PWR,GND, TXD, RXD. The Problem is that the BT module has no RST pin. Is it possible to flash the Device with Arduino? What can i do to fix it? Thanks a lot for the help.
Cu kami
By flash I guess you mean upload a sketch?
Yes, it will be possible, but you are going to have to manually reset the board, and start the upload in the first second of the board restarting, otherwise it will just go on to run the current sketch again. Some of the early ATmega based boards had to be programmed like this, with a manual reset button, it was a pain, but it worked once you got used to coordinating your timing especially as pressing upload on the Arduino IDE will cause it to compile (unknown duration) before it uploads.
So yes it is possible, but it's tricky, annoying etc.
If it is worth it is down to you!
Hi,
yes i mean it like this. I just want to upload the new sketch. But is it not possible to reset the controller with RXD and TXD? And without a reset button? Or can i build anything else? I just want to but the Jeenode in any room and sit in the living room and flash it?
Thanks a lot.
Maybe i can use another bootloader?
Cu kami
Hi Kami, I guess it could be done but it's tricky. The way a sketch loading bootloader works is this 1) ATmega is connected to power 2) Bootloader waits a second (or two) for a sketch upload to start 3) If no sketch upload started, load existing sketch and run it.
That is why the reset line is used. It literally resets the ATmega so the bootloader starts from step 1.
You could put something in your sketch so that you can tell the ATmega to reboot on a specific message, but the Arduino IDE doesn't know anything about your message, so you will have to do it yourself. Tell the ATmega to reboot, then start the sketch upload.
Also you will have to add support for this "reboot" message in all your sketches. If you forget, then you will have to go and manually reset/upload, or connect it to a serial connection with reset support to get the corrected or new sketch uploaded.
There has been some discussion of an RFM12B bootloading firmware, which would allow you to "beam" the sketch over the air, but such firmware is tricky.
Hi,
thanks a lot for the help. I will try to do this with a reset string.
Cu kami