This driver has Direction (7), Step (8) and Common (9) entries. These entries were used to be connected on TinyG (Z Axis) at Direction, Step And Ground pins.
I did some tests, but at the moment, I could not have communication between TinyG and the Gecko Driver. This driver works fine using another board (similar to TinyG).
I have observed some points about TinyG (Voltage):
STEP PIN is between 0.8 - 29 mV.
DIRECTION PIN is between 0.8 mV - 3.4 V.
ENABLE PIN is between 0.8mV - 3.4 V
Please, any information that you could give will be great !
Using and testing only Z Axis, I have detected that STEP Pin is not major than 29mV (forward motion and backward motion). Without motion is up to 0.9mV
Other two pins (DIRECTION, ENABLE) are up to 3.4V.
For the moment, I don't have measurements for the other axes.
If you are measuring with a volt-ohm meter what you might be seeing is the step line acting as a pulse-width modulated line. You would not measure 3.4v in that case, as the steps are very narrow (a few microseconds). Have you tried measuring the voltage on an oscilloscope? You should see a low base of well under one volt with narrow pulses at 3.0 to 3.4 volts.
In that case, I saw here cases where users had to use "level shifters" or "octal bus transceiver" to connect their external drivers to TinyG.
I suspect that their external drivers only accept 5V signals, and in my case the driver accepts 3v-5v signals. I'm a beginner on this and I'm trying to set up my TinyG board with external drivers. I have some nema 23 and nema 34 motors.
I'm very sorry if my questions are too elementary. Any help would be appreciated.
No problem with the questions. There are a few things that need to be satisfied for an external driver to work
- Voltage. The external driver must accept 3v pulse signals or you will need a level shifter of some sort. I like the 74HC125 or 74HC126 (OnSemi is a good manufacturer). Power the chip with 5v and a 3.3v logic input will output 5v.
- Pulse timing. The external drive must be satisfied with step pulse widths down to about 2 microseconds. Use the edge branch (412.01 or higher) if you need these widths. THe code in the current master branch (380.xx) outputs pulses about 1 microsecond width. We added some pulse stretching later which is currently not in the master branch.
- Enable. THe enable signal from the TinyG is active low.
I have used the edge branch with current version 412.01
It appears that step pulse width on master branch is not enough for my external stepper driver (Gecko G210X, 1uS - 4.5 uS).
For anybody that may have this problem (like me), just, try to use the edge branch, that branch solved my problem. Using that version I could move a stepper motor nema 34 @5A using gecko driver g210x.
It could be better if these new features (edge branch) were available on master branch.
Uhm...., let me see..., In fact, I'm in the same condition as you. I'm a beginner on these topics... Just take my comments only as reference, because I'm not an expert.
I saw the Gecko G320X spec, and there are some differences between 210x gecko drive and g320x gecko drive. (For example motor current, power dissipation, input frequency and step pulse "0" time, and...., the motor target).
To be honest, I don't know the real differences between stepper motor and servo motor, because g210x is based for stepper motors, and g320x is based for servo motors. I don't want to lie on this topic, but, I think you should do a deep research on this and what kind of motor you must use for your machine. In my case I have used stepper motors connected to external stepper drivers.
For the other side, nowadays I was using tinyg and another board with similar conditions. I have tested stepper drivers like Gecko G210X and CW-5045 on tinyg board, and both of them are working. Serious tests are not yet ready (with built machine, I'm working on that...), but, my tests were only using these stepper drivers with nema 23 or nema 34 motors. (In the case of G210X stepper driver, I have tested nema 23 and nema 34, and, in the case of CW-5045 stepper driver I was using only nema 23 motors, because for this driver the amperage limit is 4.5A and my nema 23 motor is up to 4.2A...my nema 34 motor is up to 5.0 A. As you can see, this last motor is not the right choice for CW-5045 stepper driver).
I hope this information was useful. If you have more questions, I will try to answer them with the most useful data....
Thanks for your reply...was off sailing for 2 weeks and didn't get a chance to thank you and ask some additional questions.
I'm pretty sure I'm going to go with the TinyG board, and Gecko G320X drivers with NEMA 34 stepper motors (drawing < 6 amps).
I'd appreciate any information on how you wired those, if you could provide a picture that would be very helpful.
The main thing is that you have succeeded in hooking up the Gecko G320X drivers, so I know it can be done (perhaps even by me!) if I have some guidance.
I'm close to ordering the board/drivers/stepper motors but I won't have the gantry for another month or so.
Anyway, just wanted to reach out to you and learn from your experience and I'm very happy you've been able to get that configuration working.
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