Topics

Ramps 1.4 - ST4 don´t work

riclamer@...
 

Hello every one,  it´s my first post in Groips.io.   Firstall, thanks to every one that share your knowledge to help. 

i am building the Ramps 1.4 + drivers A4988. 

I tested the motors working connected with Stellarium, and worked.   But when i try to move motors in axis RA/AZM and DEC/ALT, using the ST4 buttons, nothing happens.

And i need this function to calibrate the telescope. 

my config: 
#define ST4_INTERFACE                 ON.
I tryed too with- ->  #define ST4_INTERFACE      ON_PULLUP ,  but dont worked too.

I used this wiring schema : ( ST4 )


   Some one, had success working RAMPS to use the Basic Hand Control (just N,S,E,W buttons).

 Can help me , to discover what happens?

Thanks

Howard Dutton
 

On Tue, May 19, 2020 at 03:26 AM, <riclamer@...> wrote:
Can help me , to discover what happens?
1. Since you don't show any pull-up resistors in your circuit (which are highly recommended) you must use the ON_PULLUP setting.
2. You must wake OnStep up.  Start an Align, for example, or the motors will not move.
3. You might have a very slow guide rate set, making guide actions less noticeable.

riclamer@...
 

Hi Howard,

 I don't find any information in official documententation about the need to use resistor.
Link1 
And 
Link2
Can you update my diagram with the position and value of resistor using PULLUP?

I find this example of PULLUP,  R1 = 33k

Howard Dutton
 
Edited

This is covered in the ST4 section of the MKS Gen-L/Ramps Wiki.  We use fairly strong pull-ups of about 2K resistance (noise suppression.)

The lack of external pull-up resistors wouldn't keep the hand controller from working provided ON_PULLUP was used.  It's just there to prevent spurious signals.

Note the Ramps14 pinmap has been around for a LONG time and is used by many.  It works.

riclamer@...
 

Thanks Howard to help me to solve this ST4 function in Ramps 1.4

I really found in WiKi informatoin about resistor and PULLUP.

------------------

ST4 interface:
This is enabled by setting ST4_PULLUP in the configuration file.  If the hand-control option is used (enabled by default) additional capabilities become available, read the configuration file for more information.  The order of pins on the AUX-2 header match those of the RJ12 jack that they should be connected to (search eBay for "RJ12 breakout"):

Pin 1: +5v or NC
Pin 2: Gnd
Pin 3: RA- (D63/A9)
Pin 4: Dec- (D40)
Pin 5: Dec+ (D42)
Pin 6: RA+ (D65/A11)

Note: this configuration uses the Mega2560's built in pull-up resistors, if RFI/EMI noise on the ST4 leads is unacceptable add 2k pull-up resistors to each line.
--------------------------
So with this information i create this schema:

#define ST4_INTERFACE           ON_PULLUP
#define ST4_HAND_CONTROL  OFF




   If you inform this schema is OK,  I will try to solder these resistor and i will inform the results !

My Config: ( attached complete Config.h )
#define SLEW_RATE_BASE_DESIRED        10.0
#define AXIS1_STEPS_PER_DEGREE    64.0   ( i´m not using gearbox in this moment  only the motor)
#define AXIS1_DRIVER_MODEL            A4988
#define AXIS1_DRIVER_MICROSTEPS       16

*** At this moment i can´t use Android App OnStep to align, my HC-06 don´t connect.   I make movement of motor using Windows Stellarium connected in Serial of Arduino.


Howard Dutton
 
Edited

On Tue, May 19, 2020 at 12:09 PM, <riclamer@...> wrote:
If you inform this schema is OK,  I will try to solder these resistor and i will inform the results !
The idea is right with the resistors pulling lines up to 5V and switches connecting each pin to ground.

Some RA/DE connections are reversed etc. though.  Effects which button does what, that is all.

Howard Dutton
 

On Tue, May 19, 2020 at 12:09 PM, <riclamer@...> wrote:
#define SLEW_RATE_BASE_DESIRED        10.0
Probably too fast.  Use 2.0 then figure it out from there.

Howard Dutton
 

On Tue, May 19, 2020 at 12:09 PM, <riclamer@...> wrote:
At this moment i can´t use Android App OnStep to align, my HC-06 don´t connect.   I make movement of motor using Windows Stellarium connected in Serial of Arduino.
Easy to make the mistake of wiring this right in and damaging a pin on the HC06.  These need 3.3V level conversion 5V TX from Mega2560 to 3.3V RX on the HC06 this is in the Wiki.

riclamer@...
 

Hi Howard Dutton,

   Today a created my Basic Hand Control (just N,S,E,W buttons).

But i can't make it work in my Ramps 1.4 .


 How i am testing:

1 - i open Sttelarium in my WIndows.
2 - Then i connect to OnStep using serial.   
3 - I Sync the position , then i choose a star and click  GO.
4 - the motors perform the movement. 
5 - In the end of movement of motors, i click the buttons of my BHC, but nothing happens. 

I am forgetting something or doing something wrong ??

tks 

Howard Dutton
 

Ok, I just looked at your Config.h file again and notice the steps per degree of Axis1 and Axis2 are set at 64.0!   64.0!!!

That's ~57 arc-seconds/step and the suggested limit is <= 1.25

OnStep was never designed to handle settings like that... I'd #error the compile and not allow it if the pre-processor could do checks on floating point numbers.

That said in my testing (of your exact Config.h file except set to TMC2130's) on my Mega2560/Ramps14 board guiding did work fine just the motion (given your settings) was so slow as to be nearly unnoticeable.  Especially since you don't have hand controller mode enabled so rates are limited to <= 1X on the ST4 port.

riclamer@...
 

I'm using 64 step  because I'm not using gearbox. Just to initial test. 

I will set to 1000. And i will inform if work

riclamer@...
 

Sucess Howard,

 I changed the Steps to default 12800.00, and WORKED.

  But the PULLUP with 5V and resistor created some reboot in Arduino.  Using only the GND without resistor worked perfectly. 


Thanks for your efforts Howard.

riclamer@...
 

Have a method to i increase the rates?

Howard Dutton
 
Edited

On Wed, May 20, 2020 at 08:18 PM, <riclamer@...> wrote:
But the PULLUP with 5V and resistor created some reboot in Arduino.
You were probably accidentally shorting something somewhere...

2K resistors work fine for this, it's proven.  Well within specifications for current drive capabilities of a Mega2560 pin.  (I.e. should never crash the Mega2560 no matter what you do.)

Howard Dutton
 

On Wed, May 20, 2020 at 08:23 PM, <riclamer@...> wrote:
Have a method to i increase the rates?
Rates of what?

riclamer@...
 

Increase the rates for BHC,   have in config a method to adjust the speed to x2  for example?

Howard Dutton
 

On Thu, May 21, 2020 at 05:22 AM, <riclamer@...> wrote:
Increase the rates for BHC,   have in config a method to adjust the speed to x2  for example?
Read the Wiki:
https://onstep.groups.io/g/main/wiki/7150

Howard Dutton
 
Edited

On Thu, May 21, 2020 at 06:07 AM, Howard Dutton wrote:
On Thu, May 21, 2020 at 05:22 AM, <riclamer@...> wrote:
Increase the rates for BHC,   have in config a method to adjust the speed to x2  for example?
Read the Wiki:
https://onstep.groups.io/g/main/wiki/7150
Note that having a buzzer along with the BHC is extremely helpful, takes much of the guesswork out of it as you enter/exit the special button press modes.