Originally shared by Brandon Satterfield
For those using a touch sensor on a TinyG with Chilipeppr, are you having to add resistance to lower the LPF?
About to get out an O-scope and chase down my problem of resetting the TinyG every time I close the Zmin.
Can you provide a connection diagram (words would be OK).
TinyGV8 has the Zmin port pulled high on the tinyG board, 2.7K to +3.3V, and bypassed to gnd with 0.2uF. Most folks seem to connect a wire from Zmin switch port to the tool.
Are you doing something different?
@cmcgrath5035 thank you for the quick response.
Connection: two 16g shielded (shielding not currently grounded) wires with banana clips one to the endmill one to the aluminum plate. Zmin and ground, NO.
That sounds correct. Does tinyG reset if you just connect the two banana clips momentarily?
I am assuming you are using the proper probe command, rather than just designating Zmin as a limit. The probe command modifies the tinyG interpretation of the closure.
I have seen this in the past as well. I twisted my wires together and that seemed to help, but I still did not have it perfect. I figured the only best answer was to drive the touch probe using 12 volts and rig up a level shifter to talk back to TinyG.
@jlauer Based on John’s experience, sounds like noise. Perhaps ground your shield, at the tinyG end?
It might be interesting to add a good ceramic or mylar (not electrolytic) at the touch plate end (.1 to .5 UF, whatever you might have). Not at all clear why that would cause a reset rather than a misfire of the probe algorithm.
You did leave the switch settings as NC, correct? I guess that assumes you have NC limit/home switches.
Note that recent FW (440.xx) looks for change of state on Zmin, not a high/low level, so NC/NO for that switch is irrelevant.
Thanks guys. @cmcgrath5035 and @jlauer
No other limit switches on the machine. Just this one.
It is set at NO on the Zmin. I’m not sure I could do NC, I’m creating continuity… Correct?
I have attempted this on both touch probe and auto-level, both provide the same results.
Recently updated this board ( @jlauer , this is the coolest thing ever!) through CP.
I did notice last night using the touch sensor, if I stop the touch sensor manually, via the screen, I get the “beep beep” and the TinyG stops communicating. If I understand this is somewhat correct, but I have to reset the TinyG to get it to jog post. If I perform the same, momentarily touching the two “limit switch” wires the red light flashes and the TinyG needs to be power cycled.
I also added a large ring ferrite last night, only did two wraps, no advantage seen.
I used limit/homing and only limit, no change in response.
@jlauer I had the first set of wires twisted. That didn’t work so I went to the shielded. I took the small grounding wire out of the shielded cable on one attempt and grounded one end to the frame the other to the “-” of the TinyG, no change.
All motors are off and unpowered except the Z motor.
I have another machine sitting right next to this one on a TinyG. This one acts the same way, so I’m assuming it’s to some fault of my own.
Last night I also tried a 10pF ceramic up to a .47uF elect cap on a bread board right before the signal enter the TinyG’s board. No change in response.
@Brandon_Satterfield Try setting switches to NC. TinyG changed a while back to implement the probe action detecting a change in state, so that open to closed, the natural result of a simple probe, could coexist with NC Limits and Homes.
But if you have no other switches and they are properly disabled, this really shouldn’t do much
Are you sure that your wiring is correct?
Zmin is right next to 3.3V on the connector; grounding 3.3V would reset tinyG for sure.
Perhaps a solder cross, etc near the connector?
Try a 1K ohm or so resistor Zmin port pin to ground.
The voltage on Zmin should drop consistent with a voltage divider .
If Zmin pin remains at 3.3v, sounds like Zmin is shorted to 3.3V
In case you don’t have it, applicable Schematic page:
https://github.com/synthetos/TinyG/blob/master/hardware/v8schematics/v8h/tinyGv8h%20-%20schematic%20page1.pdf
@cmcgrath5035 thank you, I’ll try this.
Yes, sure that the wires are in pin 4 and 6 from the Amax side. This should align with Zmin and GRD. Getting a little older can’t see as well, have to memorize hole count vs reading…
I haven’t messed with the NC except one try, my logic was that normally closed would see an issue right at the check. Knowing logic is looking for any shift might be the que.
I will add the 1k from Zmin to Grnd. I was cautious of adding more resistance as I didn’t want to add too much resistance to the system. Going to ground though and using the VDR sounds like a plan. Will look at the math 4.7 and 1 and see what we are dropping it too.
Last resort will be a grounding plan if I have to get out my O-scope. Have a young guy working for us that thought that it was a small TV, probably need to do a little training on the scope anyway.
@Brandon_Satterfield OK; I have a V7 (not V8) so can’t comment on the specific connector layout, I am just reading the schematic.
The purpose of a 1K (or close) to ground on Zmin is just to test if Zmin is somehow shorted to 3.3V.
Without a resistor, you should read 3.3V on Zmin.
If you added 2.7K to ground, you should read 3.3V/2 , a 2:1 voltage divider. If you use 1Kohm, you should read about .9V or so. If you see 3.3V, then Zmin is shorted to 3.3V
Ah, understood, your wanting to do this as a test. No problem I’ll check this out this evening.
V7? Man for what you do for this community and the forum we are going to have to get Riley to get you updated!
Get on the other side of this and I’ll have to take care of you for assisting. What kind of machine are you running?
Well guys playing this evening I switched to NC and went to homing only on the Z, also turned off all other limit switches.
This seems to have worked for now. Going to level an ~ 3’ X 3’ area.
Thank you both John and Carl for your assistance today.
Carl, I had no idea. We’ll get you a v8.
Alden
That’s awesome Alden!
@Brandon_Satterfield Actually, V7 and V8 are performance identical and some aspects of the V7 layout made it easier to connect to a massive heat sink. But a V8 in my hand will make some questions a bit clearer, so thanks!
And good news that you are now up and leveling