Gen7 v1.4.1: Problem connecting to Firmware on Atmega1284P

Hi,

I've built a Gen7 1.4.1 board, but I cannot connect to the firmware. So far I have been able to:

- Upload the SetupTest.pde, and receive communication from it.
- Upload Teacup Firmware, successfully.

However, whenever I try to communicate with the board, I receive no response. I connect to the board from Windows 7, using a USB-TLL converter. Pronterface simply tries to connect forever (with the message "connecting"). Repetier-Host can connect, but commands do nothing (and obtain no response). I tried sending commands to it with CoolTerm but no message returns any sort of response.

I have also tried loading Repetier-Firmware onto the board, and had the same issue again.

My board was built with an Atmega1284P (20MHz), using the kit of parts ordered from Traumflug. I used arduino 1.0.5.

Thank you in advance for any information or advice you can give to me.

In CoolTerm, do you receive "start" and "ok" after hitting the reset button? If not, communications isn't happening. Teacup operates at 115200 baud by default, Repetier (I think) at 250000 baud. Also make sure you have the right board variant selected in Arduino IDE. Compiling for 16 MHz and running at 20 MHz doesn't match and gives odd baud rates.

There's also a single report from one person who had success with Arduino 1.0.4, but not 1.0.5.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I went back and double checked all upload settings. Upload was for the correct board at 20MHz. I also tried Arduino 1.0.4 (and 1.0.2), with no result.

When I use CoolTerm, after connecting, hitting the reset button does nothing. I don't even receive garbled text.

Well, if SetupTest.ino works, it apparently works fine at 9600 baud. You can set that baud rate in Teacup or Repetier, too, search config.h for "BAUD". Then work from there. You can also raise the baud rate in SetupTest, the code should be easy to understand.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I tried Teacup at 9600 and several other baud rates. No change. SetupTest worked fine at 115200 as well.

Is there any way to make sure that Teacup is starting? Could anything prevent the full firmware from starting?

ATmegas run all the time, as soon as they get juice. The only way to not start the firmware is to keep program flow stuck in the bootloader, which can happen if you send characters repeatedly right after a reset. This way the bootloader never times out. Pronterface had a bug doing this until recently. CoolTerm shouldn't do such things. Also, this would apply to SetupTest, too.

You could add a power_on(); right as the first command in main() in mendel.c. In lack of a debug LED, this turns the power supply on to show something is happening.

Uhm, is it possible your coil L1 is still 100 uH? About half a year ago it was found out this can cause negative voltage spikes, causing the ATmega to reset, when Marlin Firmware or Repetier with display enabled was used. Reducing this coil to 10 uH avoids this effect. As a quick fix, you can short or replace this coil with a piece of wire; you get undampened analog voltage then, like all other RepRap electronics.

If you don't have such a coil, PM me your address and I'll send you one.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Ok, I did have a 100 uH coil.

I replaced the coil with a bit of wire, and that seems to have fixed the whole problem. I can now communicate with both Teacup and Repetier.

Thanks for all your help!