I’m on my second bltouch. Antlabs replaced the first, but I’m convinced now that there was nothing wrong with it. I have a DVM on the output servo pin (I’ve tried 1.23 and 3.25) and I get no AC or DC voltage. As I understand this the PWM should register as some RMS voltage. The yellow wire from the BLTouch is connected to the pin, which is what the diagram showed.
The board is a genuine smoothie 4x
white -> Zmax signal
red -> Zmax +5
brown -> Zmax gnd
black -> Another gnd (tried it without as well)
yellow -> Currently on 3.25
Config:
switch.servo.enable true
switch.servo.input_on_comand M280 S3.0
switch.servo.input_off_command M281 S7.0
switch.servo.output_pin 3.25
switch.servo.output_type hwpwm
switch.servo.pwm_period_ms 20
Imported from wikidot
Why do you have S3.0 and S7.0 in there ? That is not how the switch module works.
Where did you copy/paste this from ? This is the third time in a month I see this nonsensical configuration snippet, I really need to find where it comes from so I can fix it/ask the person responsible to fix it, it’s misleading too many people. Thanks.
Fair enough, I saw it in another post (sorry, I can’t find it in my history). But it wasn’t working without the S values either. I had literally just added them. I just removed them again and still no voltage ac or dc on the servo pin and no actuation of the bltouch.
I can’t see anything wrong then, should work, does for others.
Can you see your config file at pastebin.com and some photos of your setup at any free image host ?
()*& it, the site doesn’t want to let me post links. Do the appropriate below. Geez. They are all https links. The images are drive google com and the config is pastebin com. Arg.
config on pastebin: http://pastebin.com/LjGpZzFE
image of servo (yellow on 3.25) and ground (black) wires on smoothie board http://drive.google.com/open?id=1Pk1XxwoxgVmYDrQQGE4AwzKCYqDC_jDuNQ
image of connector on z max with white, brown and red wires: http://drive.google.com/open?id=1mSS2srREaratrfXB1QuyRpC4pxuh1Z9lKg
image of bltouch mounted with power on: http://drive.google.com/open?id=1Z6efthsU_ziTj-3wC_ULvtM-m2IkXnBKyA
I can’t see anything wrong. Can you try upgrading to the very latest firmware, get the very latest example configuration file and replace your current one ( save the current one ), edit the ( new ) configuration file strictly only as much as you need to get the bltouch to work, remove the board from the machine, disconnect everything but USB and the bltouch, and try to get the bltouch to work ?
I’ll try this and report back. I should have tried the latest firmware but neglected that.
I tried the latest firmware with the default config and only the bltouch mods and no luck. I don’t see the point in dewiring the steppers, thermistors and loads. I get that there’s a warm fuzzy of no interference, but they are all firmly on the outside of isolation electronics and really shouldn’t be able to affect the hwpwm signal (and the XYZ movement and min stops work, the fans work and the heaters and thermistors work.
I suppose my attempt to grab the voltage off the 3.25 pin may not be working, I’m gently inserting a sewing pin in the end of the connector thinking it should hit the metal of the dupont crimp.
The only other connection is a tft display connected to the “debug” connector (Rx, Tx, +5, Gnd)
So, been doing smoothie support for 5 years, when we say “latest firmware, unmodified fresh config, nothing but usb and that thing connected” ( which we say often ) there are very good, weird, historical reasons. 95% of chances it won’t change/apply to your specific case, but if you are in the remaining 5 and don’t do this, then we are going to waste a ton of time, both of us.
This applies even more in cases like yours where my best explanation right now is “ghosts”.
Can you do the unplugging, then try setting up the switch for zprobe, testing it, and if it doesn’t work, then do that again, but using the other pwm pins on the board, each in turn ( see smoothieware.org/pinout for pwm-capable pins ).
Fair enough, I’m handicapped by 2 EE degrees, makes me feel smart sometimes. I get what you’re saying. I’ll do it in the AM when I’m fresh.
OK, didn’t wait, tried with all but the USB and 12v power off. BLTouch configured on ZMax, I tried 3.25, 3.26 and 1.23 for the servo pin and nada.
ok so I was going towards a board defect here, but 3 broken pins doesn’t sound very likely ( one would already be “one in many thousand” material ).
one thing we haven’t tried : it’s imaginable it’s not actually reading your config at all ( or reading an old version of the file ), maybe because of a problem with the SD card. can you try :
- formatting the sd card and trying again
- if you have one around, try with another sd card
It happens that I have a couple of other sd cards. I reformatted one and put just the latest firmware and config on that. No difference. BLTouch doesn’t activate and if I replace the servo wire with the dvm then no ac voltage.
I also can’t imagine three broken outputs unless they were designed fragile and the first bltouch somehow burned them. Given a PCM type signal that really shouldn’t be possible unless there’s absolutely no current limiting resistor or device - I know I wouldn’t drive such an output without one.
ANTLabs for some reason insists it has to be on Zmin and not Zmax, which makes absolutely no sense. But I wanted to say I tried it and it made no difference. I was slightly happy that logic prevailed but unhappy that an illogical solution didn’t fix it.
what does the “version” command answer exactly ?
( not going to lie, never seen something like this, building a printer on top of ancient burial grounds ? )
Send: version
Recv: Build version: edge-c819aa6, Build date: Apr 4 2018 16:52:08, MCU: LPC1769, System Clock: 120MHz
Recv: 5 axis
Ancient burial grounds? I buy my coffee fresh! I seem to be lucky this way. I’m a software engineer by profession (retired now) and I always had unique failure modes in other people’s libraries.
Is it possible I should be contacting uberclock, or that I’m missing some essential power source or jumper or some simple thing like that? I’ve been assuming that a modern quality dvm (fluke) has a high enough input impedance that I should get a reading of ~1v rms for the hwpwm signal minimum. It isn’t like an ac voltage measurement circuit should have trouble working at 20ms periodicity.
One thing I found confusing. I found P1.23 on the schematics, but I couldn’t find 3.25 or 3.26.
For what it’s worth I’m driving the smoothie board with a RasPI running OctoPI/OctoPrint.
Just in case you are making an incorrect assumption when measuring, maybe try a LED or a piezzo at different pwm output values ?
While we are looking into that sort of possible problem, can you take a screenshot of the terminal where you are sending mcode commands trying to set the switch at various pwm values ? I might be able to notice something.
I’m not sure about a piezo, a piezo buzzer? I tried hooking up an LED positive to P1.23 and no glow with M280 or M280 S3.0. The link to the terminal is
http://drive.google.com/open?id=16HpTWJmkXD4KHSFmOeJUTCHALa6oXVM4gw
Thank you for your patience. This is really bizarre, but clearly not the bltouch since there seems to be no servo output.
Piezzo buzzer, or even a small speaker, anything that’d let you hear any pwm signal easily.
M280 S3 is pretty low ( it’s 0-255 ), try M280 S200 next test just to be sure.
The terminal output looks ok. Try S200, if that doesn’t help next thing we’ll try is changing the switch to not be pwm at all ( just on/off ) and see if we can get something out of the pin that way.
hmm, it hadn’t been obvious what the range was for S, rtfm eh? But unfortunately no change, nor a change with type = digital. With the LED do I need to have an external voltage though? Is the switch something like an open collector (source) circuit where the connection is a load to Vbb or Vc, or is it a load from the drain to ground? I kinda hate not having a schematic of the outputs on the big IC chip.