BLT Touch - duet Wifi

kivlow · 17 Apr 2018, 09:12

Hello,
I cant to get it work
so i add in config.g
Z-Probe
M307 H7 A-1 C-1 D-1
M558 P5 X0 Y0 Z1 H5 F100 T2000
G31 X-22.00 Y7.0 Z1.5 P5
M557 X15:215 Y15:195 S20

I plug black with white with 240 ohm resistor to Z probe on duet wifi and red bown nad orange to +5 ground nad heater 7
so i can send m401 and m402 and probe react but in consol in Z-probe i have 0 reading on scale all time

When i try g30 bed go up (coreXY) but i have error no signal from sensor

is my blt not working correct or i have someting mess up in settings ?

p.s. i upgrade firemware to 1.21 and change m558 to p9 and nothing change m401 nad m402 work but duet not see signal z-probe is still 0 in .
When probe is up with red light i mesure voltage on black/white na i have about 3.6mV its that ok ??

dc42 · 17 Apr 2018, 09:33

@kivlow said in BLT Touch - duet Wifi:

Hello,
I cant to get it work
so i add in config.g
Z-Probe
M307 H7 A-1 C-1 D-1
M558 P5 X0 Y0 Z1 H5 F100 T2000
G31 X-22.00 Y7.0 Z1.5 P5
M557 X15:215 Y15:195 S20

I plug black with white with 240 ohm resistor to Z probe on duet wifi and red bown nad orange to +5 ground nad heater 7
so i can send m401 and m402 and probe react but in consol in Z-probe i have 0 reading on scale all time

When i try g30 bed go up (coreXY) but i have error no signal from sensor

is my blt not working correct or i have someting mess up in settings ?

p.s. i upgrade firemware to 1.21 and change m558 to p9 and nothing change m401 nad m402 work but duet not see signal z-probe is still 0 in .
When probe is up with red light i mesure voltage on black/white na i have about 3.6mV its that ok ??

It should be about 3V, not 3.6mV. Are you sure your resistor is 240 ohms? Later versions of bltouch don't need the resistor, instead you cut a trace for 3.3V operation.

kivlow · 17 Apr 2018, 10:15

something wired is happend - when i send m401 and push the probe up till gets error and blinks then i have 1000 on web interface.
after that when i send m280 p7 s160 i1 its go off
(error mode) and 0 on interface go on.
when i send 401 or 402 still 0 on interface.
p.s. its old one blt touch - when i force to error then i have on black/white about 3.8V without resistor

kivlow · 17 Apr 2018, 19:11

I order new bl touch so if new will works everything will be clear (if not i mess setting or my duet is broken )

kivlow · 20 Apr 2018, 04:35

New probe work fine but i have old one type so in manual is writen to add 240ohm resistor for 3.3 logic but in my setup work fine without it :]
Maybe it is connected with that i use 24V supply ?!

dc42 · 20 Apr 2018, 08:36

@kivlow said in BLT Touch - duet Wifi:

New probe work fine but i have old one type so in manual is writen to add 240ohm resistor for 3.3 logic but in my setup work fine without it :]
Maybe it is connected with that i use 24V supply ?!

Unlikely. Although we say that you shouldn't feed more than 3.3V into the Z probe input, in practice it will tolerate much more although we can't guarantee that.

kojderek · 22 Aug 2018, 11:05

Why You are using deploy and retract probe gcodes (M401 and m402) instead of M280.
Web configurator creates retractprobe.g and deployprobe.g wit M280 inside not M401 and M402 ??

dc42 · 22 Aug 2018, 21:02

@kojderek said in BLT Touch - duet Wifi:

Why You are using deploy and retract probe gcodes (M401 and m402) instead of M280.
Web configurator creates retractprobe.g and deployprobe.g wit M280 inside not M401 and M402 ??

M401 runs deployprobe.g and remembers that the probe is deployed. M402 runs retractprobe.g and remembers that it is retracted. So M401 and M402 are the correct commands to send the Duet to deploy and retract any sort of Z probe.

Redemptioner · 23 Aug 2018, 03:24

This is a very common problem with the BLTouch as it is basically a useless device. The design relies on some heatshrink to hold the magnet to the probe for Hal sensor and set the length of the probe, this is of course sensitive to heat making it useless when mounted anywhere near heat (like your hot end).

Do yourself a Favor and get a DC42 IR Sensor.

burtoogle · 23 Aug 2018, 06:56

@redemptioner said in BLT Touch - duet Wifi:

This is a very common problem with the BLTouch as it is basically a useless device. The design relies on some heatshrink to hold the magnet to the probe for Hal sensor and set the length of the probe, this is of course sensitive to heat making it useless when mounted anywhere near heat (like your hot end).

Do yourself a Favor and get a DC42 IR Sensor.

I have a BLTouch on a Kossel Mini and it works perfectly well to set Z to zero at the start of the print. Very reliable. No good for probing, of course, due to effector tilt but that's not really the probe's fault. I have previously had a dc42 IR sensor and never managed to get repeatable results from it so it's definitely a case of YMMV. I also have a Orion Piezo thing and that is another story!