Reprap Pro Tricolour slave board no longer working

Hi,

The slave controller on my Tricolour mendel is not having a good time. When it started it didn't have the right firmware on it. So I had to download the source, setup the arduino environment and upload the slave firmware to the board. Then it was working fine, for a while.

For multicolour prints they all failed after 5-10 mm. The target temperature for one of the slave extruders would be set to it's temperature x100. i.e. 19000 degrees or 15000 degrees for standby. This would be during a Tx Gcode instruction, which would never terminate. The firmware just kept reporting the extruder temperatures for hours and hours! So I decided to add in a bodge work around to the slave firmware, and truncate the tempertature strings to 3 characters at most. I uploaded my modified slave firmware, then the slave doesn't work at all. It fails with the following message when the machine starts up:

Printer is now online.
echo:Marlin 1.0.2 RRP
echo: Last Updated: 2013-04-11 | Author: RepRapPro
echo: Free Memory: 11130  PlannerBufferBytes: 1232
Slave init. Please wait ...
....................Slave init FAIL head 1

Firstly I compiled and uploaded the original slave firmware, but the slave still fails in the same way. I've downloaded the source of github again and tried that, still no joy. I've managed to upload the blink test firmware to the board, that does exactly what it should do.

- The firmware compiles and uploads perfectly.
- I've tested the power to the slave, that's fine.
- The two thermistors are connected and reading the right resistances.
- I've powered the machine down and checked each of the lines on the slave signal cable.
- Yes I've setting the power and reset jumpers in the right place for uploading and reset them afterwards.
- The slave board was working fine, until I changed the firmware!

I'd really like to know more about what's going on inside. Does anyone know exactly what can cause the slave to fail to start, so I have a list of things to check. Or point me at the source code and I'll have a look. Some more detailed error reporting would be great here!

Any ideas would be greatly appreciated.

Pete Blacker

Hi Pete

The Slave init test on the master just checks that sensible temperatures are being reported. The initial problems you encountered were most likely due to communication issues between the master and the slave, this should be fixed in the latest firmware release. You can send the master board an M111 command, this will turn debug mode on the slave. If you then open up arduino, and have a second usb cable to hand plugged into the slave, you can use the Arduino serial monitor to see what its doing, and what its sending the master.

Can you just confirm what your thermistors are reading if you measure them manually? They should be about 100k at room temp

If you log on to the emaker or reprappro channel on IRC, someone will be around to give more immediate help.

Rhys

Hi Rhys,

That's some really useful info.

I disconnected the thermistor inputs at the Melzi end and they were reading 115-120K Ohms. I had a loose connection on one of these when I built the machine, so I've got that bit of testing well practised!

I'll have a look at the slave comms now and see what it's saying.

Have the Master and Slave firmwares been updated in the last two weeks? Could my problem be caused by a newer version of the slave firmware trying to work with a 2 week old version of the master firmware?

Cheers,

Pete

Hi Pete

The firmware is being updated pretty much constantly. I don't think any of the recent updates should matter if you didn't update them both simultaneously but its normally good practice just to be sure.

Rhys

Got it going again!

I'm not sure why but for some reason I had to manually hold down the reset butting while uploading the firmware. Even though the slave's reset jumper was linked.

I also found out that if your turn on verbose output for uploads in the arduino preferences dialog. You get some useful information about the upload, this is how I found the problem. For some reason it wasn't uploading anything to the arduino, but still saying upload complete at the end of it!

At the end of the day, it would appear that the problem with my slave firmware was that I didn't have any!

Hope this can help someone else.

Pete

Edited 2 time(s). Last edit at 05/12/2013 06:39PM by PeteBlackerThe3rd.

Hi,
I got the same problem ... Slave init Fail Head 1 ... and I run the Marlin 1.0.3 RRP

except that I don't have the Melzi Slave board connected to the master.
I followed the build guide to print Mono first. Do I have to connect everything (slave and add. extruders) at the first place?

Thanks.