[41south]

Hi all

Have been beating my head against the wall trying to reprogram my RX Meduino board. In the past it seems reluctant to bring up the port in the Arduino IDE on my Macbook pro, but eventually works. I have no problem with any of the TX Nano boards, just the RX Meduino.

Today I have tried every combination of power on/off with the "switch"  (I use a jumper) in program mode but to no avail.

Is there an alternative way to look at programming?

I even took it off the RX board and put the diode back in - still didn't work

Many thanks for any thoughts

[41south]

I've also noticed that with the 'program' link open the board just runs normally, I thought I read somewhere that it should keep rebooting until the link is back in 'run' mode?

[werk_ag]

I've also noticed that with the 'program' link open the board just runs normally, I thought I read somewhere that it should keep rebooting until the link is back in 'run' mode?

Hi,

With the Program / Run switch open it only reboots when a serial connection is started what happen per example, when we start Cumulus.
Regarding the Meduino board, is the serial port recognized when you connect the USB cable to computer? If not, maybe it was damaged.
The serial to usb chip on the Meduino board is very close to the diode that we should remove, be careful to not apply much heat when removing / replacing the diode.

[41south]

Thanks for the clarification on the boot cycle, that makes sense.

I think in that case my Meduino is faulty, I have ordered 2 more. I tried it on other windoze    and Linux boxes and it does not show up at all as a device. I doubt that my soldering caused any harm, but who knows.

Is there a possibility to program the code via the ICSP port? That part of my knowledge is shallow 

[engolling]

I never tried to upload a sketch via ISP but flashed some bootloaders of Arduino or used the AVR Studio, but according to the manual it is pretty easy.
https://www.arduino.cc/en/Guide/ArduinoISP

Just use upload with programmer. As programmer you can use a normal Arduino, where you did upload the Arduino ISP sketch before.

Regards,
engolling

[41south]

Thank you sir, that is most helpful

[41south]

Well I took the Arduino off the RX board (so as not to feed 5V anywhere it shouldn't be   ) and programmed it successfully via the ICSP header. The only hiccup was getting a verification error but the program definitely uploaded and is running.

This worked also for a test Nano board I had, there was no verification error on the Nano

Thanks for all the help

[werk_ag]

Well I took the Arduino off the RX board (so as not to feed 5V anywhere it shouldn't be   ) and programmed it successfully via the ICSP header. The only hiccup was getting a verification error but the program definitely uploaded and is running.

The only problem when a sketch is programmed through the ICSP port is that you lose the bootloader. To be able to program trough the USB port again, first you should install a new bootloader via ICSP.
Have you checked serial communication? If the problem is a faulty serial to USB chip, you still don't have serial communication and can't connect to Cumulus or other software.

[41south]

Yes I expect that this is only a temporary solution to finish my build testing, I have ordered 2 x new Meduinos as replacement and spare.

The USB/serial connection is handled by the 16u2 I believe?

I might run the soldering iron down the connector pins in case it is something as simple as that, it was intermittent before stopping completely

[werk_ag]

...
The USB/serial connection is handled by the 16u2 I believe?
...

Yes.

When removing the Diode we should be very careful, there are very small vias near the pad closer to the 16u2. I have already damaged one Meduino, this why I said to check the serial communications.

Regards