PWM on gShield not working to turn on spindle

I have not used the PWM since upgrading to a Dewalt Rounter. I recently purchased IOT relay power strips, and I have successfully tested the function of those. I wired the relay into the S- and S+ correctly. Ig I move the spindle switch on the power supply, the relays work. If I move it to Logic, and send the M5 command (even with the Spindle speed set to 500+) it will not turn on. I measure the voltage on the D11 pin on the gShield and it is only 1.3 volts. I understand that it is not the voltage that triggers the logic, but it seemed low. Easel is reading the firmware as GRBL 1.0c and Easel Driver 0.3.9. Can anyone assist?

The M5 command is spindle off. Use M3 to turn it on. S0 will also turn the spindle off.

Check the grbl values in $30 and $31. S value must exceed the value in $30 for the PWM signal to be full on.

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Doing some probing, and I think the zener Diode on the Power supply interface is bad. It is reading an open when probed in both directions.

You can hook D11 directly to the IoT relay.


Sent M3 S12000 No Joy.

No joy on hooking up directly to D11 either.

If you use M3 S100 what voltage do you measure on D11?

When probing D11 after sending M3 S100, there is 1.3 VDC.

It appears that your D11 pin is not working correctly. What is the voltage on D11 after issuing an M5 command?

After issuing a M5, get .1 VDC. would this be the audrino board or the gshield?

It would be the Arduino (or a bad solder connection on D11 on the gShield).

Do this test. Issue the command M4 S100 and measure the voltage on D13.

4.5 VDC on D13 after sending M4 S100

I guess I will try to reflash the Audrino.

Just to check out your circuit hook D13 to the IoT relay and use M4 S100 to turn it on and M5 to turn it off.

Does that work in Easel? If not, I am ok using UGCS.

Don’t know, you can try it.

If Easel doesn’t work UGCS will.

Actually, M5 might not turn it off, use M3

m4 s100 did work on D13. M5 did not shut it off, but m3 did.

Ok, that says that your circuit is good, and there is a problem with D11.

If you are sure that the solder connection on the gShield for D11 is good then next to try would be to reflash the Arduino.

Reflashed with latest hex and had the same issue. Just purchased a Arduino Uno Clone for testing. Will have it Wednesday. If that fixes it, I will purchase an official Arduino just for good measure.

I’ve had pretty good luck with several of the clones. From my point of view if the clone works Ok. I would just use it.