Help please with Gen7 Serial Conn

Halo All,

I am assembling Gen7 1.4.1 electronic (chip obtained from Traumflug). Soldering is done, power checking is done. Now powering the board and after few seconds I can see PSU turn on and the heater bed led blinking. I think that is the setup test firmware. So it looks good. Now I am connecting it via USB-TTL adapter and open serial monitor in Arduino... I can see text running but unreadable, baud set to 9600. So it is communicating but does not look good. I also failed when trying to upload the firmware.

Please advice what could be the problem and things I shall look at.

The other problem I notice is seems I can not reset the board. I expect after it reset then it will run another cycle of test firmware. I've checked my reset switch and found wrongly connected (my reset only have 2 pins) but from the schematic I guess can connect PIN 9 to the ground ? Tried this but does not work either.

I am using E'go USB-TTL adapter bought from ebay.

Thanks.

Quote

my reset only have 2 pins

So you changed the layout?

In this picture: [reprap.org] you can see how the two bottom pins of the reset switch connect two parts of the GND (light blue) tracks. For reliable communications, properly grounding the left two pins of the serial connector is essential.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

No I don't. Just realized it when about to solder, a first timer mistake .
I just jumper it according to the green line and put the switch two legs vertical to connect the ground with reset pin. The reset is working fine.

On the serial, I also tested using Arduino Uno by removing the chip so it just function as usb-serial adapter and got the same result: receive unreadable text. So I guess can rule out the USB-TTL adapter issue.

I check and fix some soldering but no luck so far.... don't know yet what else to check....

Btw, my crystal is 16MHz. Could be this a problem if the chip bootloaded with 20MHz?

Edited 1 time(s). Last edit at 12/22/2012 08:05AM by zungmann.

Some updates:

I convert my arduino into ISP programmer and using it upload the bootloader, just want to be sure it is using 16MHz. First tried using IDE to burn the bootloader. It said successful and I think so because the led no longer blinking, so the test firmware already overwritten, at least something is written into the chip.

I tried to upload Teacup firmware into it but failed, time out. Did it so many times and pushing the reset button as suggested, no luck so far.
Then I upload the firmware directly using programmer and it works. I can connect using Pronterface, sending M114, M115, M190 and M191, are all working fine. I also tried to upload the test firmware directly using programmer and the serial line working perfectly.
But off course there is no bootloader.

Then I tried second time to burn the boot loader, now is using command line and burn successfully. I tried again to load a sketch and failed again...

When running at 16 MHz you need a bootloader compiled for 16 MHz. And there's no drawback in running a controller without bootloader.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY