Hello everyone.
Trinamic stepper drivers and various low cost Chinese clones have been on the market for some time now.
Compared to the A4988, these drivers are silent and in theory could solve the problem of radio interference during the operation of the Satnogs rotor equipped with a stepper motor.
Has anyone tried replacing the A4988s with TMC drivers before?
I did it but to no avail, it does not work, probably the firmware on board of arduino needs to be reconfigured with the TMC2208 libraries and perhaps the pinout.
If we were successful we could solve the noise generated by the drivers.
Also on my 3d printers equipped with A4988 I have significantly improved instead by inserting between the driver and the stepper motor the TLsmoother which are diode circuits that do not allow return eddy currents from the motors, significantly cleaning the signal and making the printer silent.
Has anyone tested this? I would be curious to share the evidence made.
IZ5ZR
Hi,
I just built my rotator based on the sarctrac mini satellite rotator and I’m having lots of issues with the a4988 being very noisy on 2m.
Did you get a chance to try the tmc2208 drivers? do they really fix the rfi issue?
73 de IU2OZH
Hi.
Unfortunately not, I need to buy TMC2208 to try, but I confirm that A4988 are very noisy driver so i have shielded moto cables and power cables becouse power cord seems act as antenna for irradiate noise, infact if you move that cable noise change
IZ5RZR
Hi Massimiliano,
I ended up swapping out the A4988 with the TMC2208 and I can confirm that the difference is between night and day! If anyone is planning to build a rotator with stepper motors make sure you use this type of drivers…
Do you mind sharing how you shielded the cables?
73 de Giordano IU2OZH
Hi Giordano, well to know!
Here is link about my shield rotator pictures
Ciao
Thanks for this info! Are there any code changes needed if swapping between the 4988 and the 2208? In particular, I’m using the Arduino Uno/CNC shield for my v3.1 rotator but having horrible noise with the 4988 despite shielding/ferrite beads,braiding cables etc
Hi,
I’m not using the SatNOGS firmware but the one from this project Mini Satellite-Antenna Rotator Mk2 - SARCNET, I’m also using the CNC shield and the only change I had to make to the code vs the 4988 was that the direction pin in inverted and that the minimum step size is 1/16 instead of 1/32. So you can take out the 3rd jumper from the shield…
On a similar note, this project for a magnetic loop controller has a nice circuit that is used to ground and isolate the stepper communication lines.
If anybody is handy in PCB manufacturing this would be a nice addition to the rotor design. Check out the schematics at To automatically tune a Magnetic Loop Antenna - Loftur E. Jónasson - TF3LJ / VE2LJX
Well, so if I want to change TMC2208 instead A4988 on a SatNOGS original pcb v 1.2 and firmware I must change pinMode to work in 2 microstep??? (cause TMC2208 minimm resolution is 2 microstep)
/Enable Motors/ (A4988) vs (TMC 2208)
pinMode(EN, OUTPUT);
digitalWrite(EN, LOW);
/Step size/
pinMode(MS1, OUTPUT); -------->>> pinMode(MS1, OUTPUT)
digitalWrite(MS1, LOW); //Full step —>>> digitalWrite(MS1, HIGH); // FOR 2 MICROSTEP
IS IT CORRECT?
TMC2208/A4988 TMC2208/A4988 A4988 A4988 TMC2208
MS1 MS2 MS3 Microsteps Microsteps
low low low 1 8
high low low 2 2
low high low 4 4
high high low 8 16
high high high 16 16
AGIS CAN YOU HELP US? …couse if working we will eliminate noise on Satnogs Rotator
Hi,
I am using TMC2208 drivers.
I did not change any of the STANDARD Satnogs software settings.
I did have to reverse 2 wires on each stepper motor to get correct direction(This can be done in software if required).
For microstepping I removed all jumpers(MS1 LOW, MS2 LOW, MS3 LOW, MS3 is not used on TMC2208).
Here is a very helpful link.
Very important is TMC2208 appears upside down compared to A4988, Double check.
I did not and let the smoke out of my 1st couple.
Hope this helps.
Ok guys. A few updates.
I inserted the tmc 2208 drivers in the v1.2 board that previously mounted the A4988, in fact you have to reverse the wires of the motors otherwise it doesn’t work. Then done this they leave. But now the problem of the microstep configuration arises. The TMC2208 drivers apparently do not work in FULL STEP, but start from 1/2 up to 16 microsteps.
Is only pin MS1 defined on the Satnogs stepper motor.ino code which is put in LOW (so it should be GND)?
Since the MS2 is not configurable, which from the board in the picture seems to be grounded so the drivers would seem to be working at 8 microsteps, can you confirm my thesis?
How can we set the TMC 2208 to 1/2 microstep in order to still have more torque on the motors than 1/8 and not modify the parameters of the .ino code too much?
In theory from my first tests on the .ino code the variable SPR (step per revoluion) of 200 value should be multiplied by 8 so SPR 1600 better to put the rounding? (SPR 1600L) ?.
In this case, the speed, delay, etc. parameters for motor control must also be greatly increased.
If with the TMC we are able to eliminate the spurious compared to the A988 we greatly improve the reception on the VHF band.
I hope you can help me
IZ5RZR