Another BLTouch Topic

The_Mechanic

I've some news about my problem.
As @Phaedrux told me I've changed the PWM port to the first one on the DueX2 and it works since then.
Meanwhile I've updated to RRF 3. After I've set the config like the older one with RRF 2 it works again.

Now I've thought why not testing it again, maybe it was a firmware problem?!

Here are the line out of my config.g

M950 S0 C"duex.pwm1" ; create servo pin 0 for BLTouch
M950 S2 C"duex.pwm4" ; create servo pin 0 for BLTouch

I've two BLTouch's for testing. The first one works since the workaround and also on RRF 3.
After another test with PWM port 4 and 5 I come to the conclusion that it must be a hardware problem. PWM port 4 and 5 do not work.

There is nothing in the config-override.g that could occupy the ports.

Here's also a picture of my DueX2.

Has someone a idea?

The workaround from @Phaedrux does work and solves the problem for me so this topic can be marked as solved.

Phaedrux

@The_Mechanic said in Another BLTouch Topic:

PWM port 4 and 5 do not work.

How did you test that they do not work? Are you also using different M280 commands to reference the different pins?

The_Mechanic

@Phaedrux
I've sent M280 P2 S120 (BLTouch self test) through the console.
I don't change the P2 in my M280 command because the only change must be done in the config.g for the PWM port.

M950 S2 C"duex.pwm4" (I've changed the '.pwm to .pwm2, 3, 4 etc.)

It works on the other ports.

The strange thing about these two PWM ports is that they have 5V (4.881 V measured with a multimeter).

There must be something wrong with the PWM signal.

JoergS5

@The_Mechanic There is a thread https://forum.duet3d.com/topic/10654/bl-touch-and-the-duex-5/65 at the posts starting 6th Nov 2019 of about PWM5 and a jumper, maybe this helps finding the reason.

The_Mechanic

@JoergS5
Thanks for that hint. This was a prolem I had in the past. But actually all ports do get 5V.
There must be something else wrong.

JoergS5

@The_Mechanic your heater 6 is not blocked (because PWM5 and heater 6 share resources)?

Maybe your problem has something to do that your Duex 5 board has version 0.8. But I did not find something special yet (minor MOSFET ... changes).

The_Mechanic

@JoergS5
Don't get me wrong. It's a DueX2. I've read through these two boards and the only differences are the three TMC2660 that are not soldered. Am I right?

I'm using the expansion board only because of my three z-axis, the BLTouch and two fans, that's all.

JoergS5

@The_Mechanic your image says Duex5:

Duex 2 is with 2 drivers, 5 with 5.

The_Mechanic

@JoergS5
Your're right. Thats wirtten on the board but it's a DueX2.

M122
=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 3.1.1 running on Duet WiFi 1.02 or later + DueX2
Board ID: 08DDM-9FAM2-LW4S4-6JTD6-3SJ6L-1LVRY
Used output buffers: 3 of 24 (23 max)

I think thats because they share the same shematic.

JoergS5

@The_Mechanic thanks for explaining, this makes sense.

The_Mechanic

I've found something interesting.
@JoergS5 gave me a hint.

My DueX2 is a version 0.8 and when I read the features section from the DueX2 and DueX5 I see this:

Duex 2 v0.8 and older

2 additional TMC2660 stepper motor drivers with stall notification.
2 additional extruder heater outputs.
2 servo outputs with 5V power and 5V signal levels, sharing control channels with the heaters. So you can use unused heater channels to drive servos.
2 additional endstop inputs with indicator LEDs and 3.3V/5V voltage selection. These are also usable as outputs.
6 additional PWM controlled fan outputs*, also usable for driving LEDs etc. The output voltage may be switched between 5V, 12V and VIN .
4 uncommitted general purpose I/O pins.
12V switching regulator, for generating a 12V supply for fans, LEDs etc. when the VIN power is higher than 12V.
2 additional thermistor inputs.
Support for 2 more thermocouple or PT100 daughter boards, supporting up to 4 more sensors.
Optional 5V external power input for powering servos, fans etc.

Duex 2 v0.8a and newer

2 additional TMC2660 stepper motor drivers with stall notification.
5 additional extruder heater outputs.
5 servo outputs with 5V power and 5V signal levels, sharing control channels with the heaters. So you can use unused heater channels to drive servos.
5 additional endstop inputs with indicator LEDs and 3.3V/5V voltage selection. These are also usable as outputs.
6 additional PWM controlled fan outputs, also usable for driving LEDs etc. The output voltage may be switched between 5V, 12V and VIN .
4 uncommitted general purpose I/O pins.
12V switching regulator, for generating a 12V supply for fans, LEDs etc. when the VIN power is higher than 12V.
5 additional thermistor inputs.
Support for 2 more thermocouple or PT100 daughter boards, supporting up to 4 more sensors.
Optional 5V external power input for powering servos, fans etc.

Now the crazy part. I have a 0.8 and not a 0.8a but I can use the servo ports 1-3. This is really strange and does not apply to any logic.

@dc42
May you could tell me where I'm wrong or misunderstand something?