Grbl Freezes at Prompt about grbl HOT 8 CLOSED

Strange. I don't recall running into a problem like this. It seems like that your connection is fine, but grbl may be crashing during the initialization. Not sure why. Does it always stop at "Type '$' to dump c" or does it randomly change and stop somewhere? How are you flashing the hex file?

Here's a couple of things you could try.

• When you get it running, re-write all of the EEPROM settings manually. Every once in a while, the EEPROM becomes corrupt after a version upgrade. This bug could indirectly be the source, but not likely.
• Usually *nix installations have a command line terminal program called 'screen'. I use this on a regular basis and know it works. If you have it, try it out. You basically type: "screen /dev/tty.usbmodem" or whatever your usb device path is. To exit the program, press ctrl-a and k.

I'll also download and install that 0.7d hex file to see if there is anything wrong with tonight.

from grbl.

Thanks for the quick response!

It always stops at that exact place when it fails but when it works it works completely.

I flashed the hex file to a virgin Uno using a modified version of the Mac instructions found in the wiki, it's very similar to the Linux process. I'm actually writing a script to make it much easier for new users to flash grbl in the future.

I'm fairly new to this myself so when you say "re-write all of the EEPROM settings manually" I think you mean to manually set all the settings that show when I type '$' and press enter, on one of the times that it doesn't freeze, is that correct?

I'll give screen a try and see what happens when I get home.

As for re-flashing the Arduino, I understand that grbl overwrites the Arduino bootloader, will I have to re-burn the bootloader with an AVR programmer now that I've flashed it with grbl or can I just flash it the way I did before if I want to change firmware? What about going back to factory?

If it's okay with you guys I'd like to update the wiki with everything that I learn during this process as a way to give back to the project, I'm not much of a programmer but I can definitely write documentation!

from grbl.

Weird. It's strange that it stops exactly at the same point. When grbl prints those characters, it doesn't really do anything special, just prints from flash memory the welcome strings.

So, I have both a DIP and SMD Uno that I test on, and neither show this problem with the compiled 0.7d hex in the downloads. I'm able to connect ok. I'm thinking that this might be some kind of problem with the handshaking with your computer. Have you tried a different computer to eliminate yours? But let's see if another terminal or hex file does anything different first.

As for re-flashing, it shouldn't write over the bootloader, at least from what I can tell. I could be wrong, but I've never had any problems uploading Arduino IDE programs back onto it after I've flashed grbl. So I think you should be fine.

Please feel free updating the wiki! This after all is a community effort! Many thanks! :)

from grbl.

Have you checked your wiring? Maybe grbl sends the welcome message to the tx queue and then continues to setup some pins as output that are sometimes shorted, sending the atmega to nirvana.

from grbl.

Alright, so here's an interesting update. I plugged the Arduino back in and and tested it again and it worked once right away and then I couldn't get it to display the full prompt after that. I decided to start with Jens' suggestion and removed all my wiring since it was just breadboarded to my stepper controllers for testing and it's only 7 wires. After removing all the wires the problem went away and I was unable to make the Arduino fail. I wired up each stepper controller one at a time to test each one in case one was shorted, but with each one connected I got the full prompt. Then I hooked them all up at once and tested and still got the full prompt and so far I have been unable to make it fail with any combination of possible wiring errors!

Many thanks for both of your suggestions, I'll post back if I discover the original cause of the crash!

from grbl.

Ah. Here I am worrying that it was a software problem caused by something obscure and would have been really hard to track down. Whew! Anyhow, it was good to hear that you got it working! And thanks for letting us know!

from grbl.

It looks like a misunderstanding of the pinouts is what caused this. I wired up my stepper controllers according to this chart and instructions "http://dank.bengler.no/-/page/show/5473_connectinggrbl?ref=mst" This lead me to have the stepper I was testing plugged into digital pins 0 and 4 on the Arduino, labelled as RX and PWM 3. This is of course wrong and caused all sorts of undesirable behaviour such as the motors stepping during RX. The correct pinout appears to be:

Xstep=2 Ystep=3 Zstep=4
Xdir=5 Ydir=6 Zdir=7

I'm fairly sure that the cause of the issue was having the RX and TX lines tied to the stepper drivers.

from grbl.

That would likely do it! Hopefully the wiki will soon be fleshed out with everything from pinouts to connecting to grbl and using it. To prevent this problem again, I'll start putting the wiki pages in order to get them started for people to update.

from grbl.