EEPROM parameters

Hello evebody,

I'm new on this forum and it's my first post. I'm french and live in New Caledonia, in south pacific near the est of Australia. So could you be indulgent with my poor english ;-)
I just bought my first used 3D printer, a G3D, similar to Prusa I3.

So my question is :
When one EEPROM parameter is define and written in EEPROM, wich parameter is considered ? EEPROM parameter or Marlin parameter ?

thank you very much for your answer.

Best regards,

EEPROM is a function that allows to modify firmware (Marlin) parameters and store them without the need of "reflashing" through the Arduino IDE. You modify the parameter and save it using G code.

Thank you for your answer.
G code is something like M5xx, I remember to read something about that.

So if I send M501, I get this following message :

>>> M501
SENDING:M501
echotored settings retrieved
echoteps per unit:
echo: M92 X80.00 Y80.00 Z2013.30 E836.00
echo:Maximum feedrates (mm/s):
echo: M203 X400.00 Y400.00 Z3.00 E20.00
echo:Maximum Acceleration (mm/s2):
echo: M201 X7000 Y7000 Z25 E10000
echo:Acceleration: S=acceleration, T=retract acceleration
echo: M204 S2000.00 T2000.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)
echo: M205 S0.00 T0.00 B20000 X15.00 Z0.30 E3.00
echo:Home offset (mm):
echo: M206 X0.00 Y0.00 Z8.00
echoID settings:
echo: M301 P31.43 I2.34 D105.57

It's means that "steps per unit" parameters used when Arduino start will be "X80.00 Y80.00 Z2013.30 E836.00", not parameters defined in configuration.c ? Am i right ?

EEPROM pulls that info from Marlin configuration h file, so those parameters are defined in configuration h.

It will be good for you to open Marlin firmware with an Arduino IDE and look at the configuration h file and all its values, so you can understand how the firmware works and which parameters you can change via EEPROM.

M92 is the steps per mm
M203 the feedrate
M201 acceleration
M204 extruder acceleration and retraction
M205 jerk
M206 offsets
M301 PID

All these values can be changed via EEPROM, there is many more that will be need the IDE to be changed.

[github.com]

This is an example of what you will find in configuration h file.

In the configuration.c I've downloaded, I have these parameters :

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,500*8,760*1.1}

whenI send M501, I get these parameters :

M92 X80.00 Y80.00 Z2013.30 E836.00

number of steps for Z and extruder are different !

The simplest to explain is E 760 X 1.1 = 836 it's just syntaxes, you can put the multiplication factors or just the result. Now with Z you have an issue, 800X 5 is 4000, the 2013.30 means that your z stepper it's only doing half steps (1/8 instead of 1/16) to fix this issue and get the right value you need to check that all the jumpers under the Z stepper driver are present, and if they are most likely your driver is damage and need replacement.

You can try:

M92 Z4000
M500

Then do M501

Most likely it will show again the 2013 value, if it shows the 4000 value, move Z up and down 10mm and measure it to check it's moving that much (Give it some space from bed) because most likely it will move double the distance. If it moves 20 instead of 10, the you'll prove yourself that the axis is not micro stepping correctly.

Thank you very much ggherbaz
after checking, effectively jumpers for Z stepper driver is different. All jumpers for all other drivers and only 2 jumpers for Z axe driver.
Do I have to change that ?

Yes, if you want good quality prints you need to have all 3 jumpers installed, if you don't have one to put, you can get them pretty cheap on eBay, or if you can't wait and are good at soldering, you can solder them together.