Reprogramming Ramps I/O board for Extruder Calibration

I have been working for some time now to get my Prusa/Mendel printer to print a decent print with zero success. Too much plastic, bubbles, blobs, missing plastic, short tracks on some infill and the list goes on. So many problems that I have scrubbed all 3D printer software and files from my computer and registry and have started fresh.

Calibration of my printer is step one and is giving me grief.
I am having difficulty changing the amount of plastic in the calibration of my extruder. The changes don’t go into effect as expected.
I am using Arduino 0023, Ramps4 electronics, Slic3r, Repentier-Host, and PLA 1.75.
I have noted on the forum others having similar problems apparently caused because the I/O board’s electronics are not set to be reprogrammed. The solution is to reset the board to accept reprogramming.
In Sprinter there is the “configuration.h file” which gives the options to make the changes by using one of 4 codes detailed below.
*******************
The microcontroller can store settings in the EEPROM
- M500 - stores parameters in EEPROM
- M501 - reads parameters from EEPROM (if you need reset them after you changed them temporarily).
- M502 - reverts to the default "factory settings". You still need to store them in EEPROM afterwards if you want to.
- M503 - Print settings

The way I programmed it was by changing the one line as below
// define this to enable EEPROM support [I DEFINED IT AS M502 4/13/13]
#define USE_EEPROM_SETTINGS M502

This worked once, I made a change, but not enough, I still need to adjust my extrusion rate further but the I/O board does not accept the change when I go through the reprogramming process.
I do not understand electronics very well, so am not sure I did this correctly.
Question 1: Would someone explain the 4 code options in simple layman’s terms
Question 2: Did I make my change using the correct syntax (but with the wrong code)?
Question 3: Which code should I use to be able to reprogram the I/O board
Question 4: Will the changes be “permanent” (not require reprogramming ), but remain changeable in the future?

Any help would be appreciated.

Bob

I am sure you have to press the reset button on Ramps for the new code to take effect?

Pressed the reset each time, still acted as noted.

Bob

Reset is unneccesary for RAMPS, the uploader can reset the board remotely.

As for the problem, with EEPROM enabled, there are three sets of settings stored on the processor.

One is stored in the firmware itself. One is stored in ROM, and the one actually used is stored in RAM. On boot, the firmware retrieves the copy from ROM and uses that as the active set, which means that it won't pick up new settings from configuration.h. You can fix that by disabling EEPROM altogether, or by sending:

M502
M500

from the host.

M502 loads the settings from firmware into RAM, M500 stores those settings in ROM.

The intent of EEPROM is that you can configure the machine in software rather than have to compile and upload new firmware. In this instance, you would send

M92 E[steps per MM] ; to set the new steps/mm value

And when you have a value that works

M500 ; to save that value to EEPROM.

Thanks Andrew, I think I understand a little better now. I'll try later today and repost my results.

Once again, thanks!

Bob

Andrew, my system now retains the changes and is now calibrated.

Sure is nice to have all the helpful and knowledgable forum members!

Bob

Edited 1 time(s). Last edit at 04/26/2013 10:56AM by BobHewson.