Stepper config problems

[Sebastian]

Hi,

i finally build the simple controller with a DRV8825 and a Nema 11 / 1,8° ,just the Temp probe and Switches. Installed Ascom and standalone Software.
Programmed the Arduino just with the Tempprobe activated and the right driverversion.
Adjusted the Motor current like described in pdf over the pod.

My calculations for Stepsize say:
Mak with reducer = f5,7f5,72,2= 71 CFZ
One revolution = 10mm travel measured
So i decided to go with 1/8 Stepping (2008=1600)to get:
(101000)/1600 = 6,25
71/6,25 = 11,36 Steps in CFZ
Maximum travel is 6 revolutions (with 1/2space at both ends)
So max Step should be 1600x6=9600

Now i opend the standalone software, and tell him maxsteps, cfz and 1/8 stepping, slow mode.
But that wont fit. Not enough movement. After checking over and over i just tried to start with full step.
When i say "go 200" in Fullstep mode it turns one revolution fast.
When i say "go400" in 1/2 Step it turns very slow maybe 10% o a revolution.
When i say "go800" in 1/4 Step it turns one revolution
When i say "go1600" in 1/8 its the same like 1/2 Step , just some movement maybe 10% of a revolution
When i say "go3600" in 1/16 it turns like hell and hit the the edge around 4000Steps after 6 turns.
So whats wrong with it?

Sebastian

[brownrb]

Hi Sebastian
It sounds like the connections between DRV8825 and Arduino for the MS (micro-stepping lines) is wrong.

There are two possible things to look for
- Using the wrong firmware
- Wired incorrectly.

You did not say whether
1-you are using a PCB, and if so which one?
2-what firmware file you are using?

There are several different versions that use drv885 as the stepper motor driver chip.
But the MS pins they use are not the same. If for example, you make a DRV8825 board and try to load the DRV8825HW203 firmware on it, then microstepping does not work properly.

For a specific firmware then the pin connections are listed in the myBoards.h file.

For example, looking at the firmware myFP2_DRV8825HW203_324, the myBoards.h file has

#define DRV8825DIR            3       
#define DRV8825STEP           4
#define DRV8825ENABLE         8 
#define DRV8825UTFTENABLE     A4
#define DRV8825M2             5
#define DRV8825M1             6
#define DRV8825M0             7

Another example for myFP2_DRV8825_324, the myBoards.h file has

#define DRV8825DIR          3             // drv8825 control lines
#define DRV8825STEP         4
#define DRV8825ENABLE       8
#define DRV8825M2           7             // for easydriver, do not connect
#define DRV8825M1           6             // for easydriver, connect to MS1
#define DRV8825M0           5             // for easydriver, connect to MS0

as you can see, the firmware for drv8825_hw203 does not have the same M0-M3 pin nu,bers compared to the drv885 firmware.

Now look into the myBoards,h file you have and make sure your Arduino pins match the correct pins of the DRV8825

If you have programmed a controller a number of times WITH different firmware files I would recommend you first run the program ClearEEPROM which is found in the Tests folder. This clears out any configuration left over from previous versions.

Let me know what happens.

Regards
Robert

[Sebastian]

Hi Robert,
thanks for the advices, i will take a look this evening. Fist i have to eat my b-day cake :-)
Sebastian

[Sebastian]

Hi Robert,
i used the "Rev13 DRV8825 myFocuserPro2M" pcb with
myFP2_Firmware_324.zip
From that zip i used the "myFP2_DRV8825_324"

I checked the lines . M0 and M2 are wrong

Firmware says M0 = Pin 5
M2= Pin 7
M1= Pin6

My DRV8825 connects like this
M0 = Pin 7
M2 = Pin 5
M1 = Pin6

Dir and Step are right

So i rewrite the firmware by changing these two numbrs and reprogramm the Arduino with it?

[Sebastian]

Hi,
i cleaned the eprom and uploaded the firmware "myFP2M_324" from the myFP2M folder
In this ino the M lines are the right way. No it works.
Why i not used this firmware wich the pdf also points?
Because the folder says "Arduino Firmware for myFP2M Prebuilt Controllers Only"
So this is a bit confusing because i have no "prebuild" one so i thought its better to use the
"myFP2_Firmware_324.zip"
I dont know wich differences there are beside the M line assigment but as written, its working now.
Stepper sounds much better and is turning the right speed depending on the stepping i programming
Sebastian

[brownrb]

Hi Sebastion

Nice to hear that it is working.

The myFP2M software is only for "pre-built" controllers that I had put together. As such they have different firmware and trying to use that M firmware on another type of controller will fail.

Over the years since 2014 there have been different my focuser products.

myFP
This was version 1 and moonlite compatible. Will not work with myFP2

myFP2
Version 2, has its own special firmware and not nork with anything else

myFP2M
The ready made controller only

myFP2N
Nextion touch screen version of myFP2

myFP2ESP
Early version of wireless myFP2, using ESP8266 chip, no further updates

myFP2ESP32
Latest version of myFP2 using ESP32 WiFi chip.

Regards
Robert