Hopefully this is the proper place for this, please feel free to move. Have been beating on this problem for days and were going nuts. There appears to be???no communication between the controlling software(Candle) and the CNC. There are 3 stepperonline 542 drivers, 2, 3amp steppers and 1 2.8 amp, Arduino UNO with breakout board. Pics attached. I Soldered up a test board so I know the driver to motor connection is fine. We can control the speed and direction of the steppers. All the DIR and PUL leads were verified and checked for any resistance. There is 5v on the positive side, 24v on the drivers.. Candle was checked for proper port, when connected it goes to "idle" indicating it is connected and coordinates change when jog keys are clicked. User command keys were programmed to send G code manually and tried. Tried 3 different cords, has a new UNO which my laptop had no problem downloading grbl. too. Nothing helps. the machine is motionless. Only inconsistency I have noticed is the TX/RX lights flash like crazy when Candle is turned on. I know it's something simple that I am missing and it's killing me. Any suggestions gratefully appreciated.
Just a stab here, but have you tried switching $4 in grbl settings? If its 0 try 1. If its 1 try 0. Save and reset.
cannot be that, the enable lines are not wired in at all. please confirm that the motors lock up when power is on. if they dont you have a power problem, if they do you have a step/dir wiring problem. the flashing lights on the Uno mean that Candle is talking to the Uno ok. (BTW Candle has not been updated in years so you may want something more up to date like OpenbuildsCONTROL or bCNC)
Thanks for responding Drivers have power. Photo shows test circuit attached. Can control the pulse with the pot and direction by pressing the button. All work. Originally checked continuity on the limit switches, now they are completely disconnected. "candle" consol shows grbl 1.1h installed, also $4=0. TX and RX flash constantly even when no info is being exchanged. Guess next step is to try your app recommendations.
Applications constantly poll Grbl for position feedback to update the DROs - i.e NORMAL behaviour Lets eliminate CANDLE, try OpenBuildsCONTROL from software.openbuilds.com Make sure you didnt cross your step/dir wiring (step to dir, and dir to step for example)
Switched to openbuilds control..no change verified all the connections again. Can I ground the PUL pin directly on the driver without damaging anything and see what happens??? It acts like it is not going low though putting the meter across a ground and 5v pin on the Arduino gives me a reading so I assume the ground is present.
Pul+ should be going HIGH (signal from Grbl pin). The other pin should be GNDed And all your GNDs (including from the Arduino) should join together
The drawing I got off this forum said attach the DIR and PUL plus pins to 5v and the negative to the Arduino outputs so their were no changes to grbl. I'm confused!!
Pic is under Cnc builds/unknown terms. Both Giarc and Kyo said + pin is 5v . I did just notice that the enable + pin has 5v though the neg. is not connected. Could that be it??
No, enable (when nothing is connected) is already enabled (at least on the dq542ma's) Kyos wiring is one option, but i prefer the other way round. May very well be your issue right there
@ca. 280, if you didn't solve your problem yet, try changing the common on the pulse and direction to the ground, or negative, and have the positive controlled by Arduino.
Thanks to all who responded. Switching the leads, ground on the - pin and the + pins to the arduino did indeed fix the problem. That being the case, when would you ever use the drawing I was referred to that put 5v on the + pin?? Is it associated with wiring the enable pins?? Any way on to setting the parameters. Thanks again.
Refer to gnea/grbl But the "signal to + input" is more standard, and also the Grbl default. The only reason one would wire it the other way, is if the drivers needed a higher current to switch - as an arduino pin can sink more current that it can source. Think chinese stepper drivers. The good ones like DQ542, DM542, DM556, etc have decent inputs that switch fine with a couple mA
or if you had a breakout board (BOB) with open collector outputs, they can only pull down so you get an 'active off' signal.
