I was wondering if there was anyone with experience in controlling a few hundred solenoids via the Duet WIFI? I have looked online on methods people use basic arduinos but it seems like a lot of the information is outdated. Any guidance into what expansions boards I can use would be super helpful!

I would prefer to use the Duet architecture because it is so handy and I can post my findings here for future reference!

@dc42 I am using a color spectrum analysis from the openCV library.

Okay I think I understand. I remember those DRV8860 drivers from the old RAMPS boards a few years back. I could daisy chain all the DRV8860's together on my own little breakout board, attach the signal pins to the outputs of the DRV8860's, then I connect the inputs to these SPIO pins:

How do I send my serial signal from my computer/web interface/gcode file to those pins to control the DRV8860's?

@snoozer It is 2019, PLC is expensive, inflexible, heavy, clunky, and it is just outdated tech. I also want to control the whole system through the duet and off the shelf IC's. The duet and arduino in general is awesome to work with.

@Hardware_SortingRobotics I'm seeing now that the 6XD documentation does actually have the correct pins listed. This information is, however, incorrect on the "connecting thermocouples" page.

@Hardware_SortingRobotics @CHRISHAMM We just discovered a serious discrepancy in the thermocouple daughterboard documentation.

When addressing the thermocouple daughterboard, spi.cs0 does not address the first sensor on the daughterboard. The documentation states that the pins are spi.cs0-spi.cs3. We have found that the actual addresses are spi.cs1-spi.cs4 instead. Spi.cs0 is not recognized by the system as a valid pin name.

@Hardware_SortingRobotics With some further testing, setting the input pin to spi.cs1 causes the temperature readout to go to 2000C instead. This is a type k thermocouple btw.

@gloomyandy Yes this is true. I copied and pasted this code into the post sloppily and must have mixed these up. The problem persists even when the heater/sensor numbers match.

Hello,

I am currently trying to utilize the medium-current output pins on my Duet 6XD (out7, out8) to drive a pair of external SSRs. These SSRs are hooked up to heaters which are being measured with thermistors, which are connected to the Duet board. My objective is to use the 12V or VIN PWM output to drive these SSRs like I would any other heater, using M950 to set them up as a standard heater, and allow the duet to vary the PWM accordingly to control the heat output.

My issue is this: When I measure the voltage differential between V_OUTLC1 and out7-, I get a steady reading of VIN (24V). The config file runs just fine, setting up the heaters as expected, but the output is high by default. Here is the config setup:

M308 S2 P"temp2" Y"thermistor" T100000 B3950 ; configure sensor as thermistor
M950 H2 C"out7" T2                           ; create nozzle heater output and map it to sensor
M307 H2 B0 S1.00                             ; disable bang-bang mode for heater  and set PWM limit
M143 H2 S275                                 ; set temperature limit for heater
M563 P2 S"Jar Heater" H2 F0                  ; define tool
G10 P2 R0 S0                                 ; set initial tool active and standby temperatures to 0C

Inverting the signal using an ! doesn't change anything either. It seems like these output pins are not switching at all, as my oscilloscope shows a steady voltage, even during heater tuning at 0.1 max PWM. I have also tried setting up the same pin using M950, but as a GPIO. Using M42 S0.5 does not have any effect on the voltage either, it just stays at 24V with no PWM switching. Please help!

I have been trying to get a brand new thermocouple daughterboard to work on my also brand-new Duet 3 6XD. Unfortunately, I have not been able to get the board to read temperatures, or output any readings at all.

We have tried many different configurations in firmware. This is the current config we have set up. We have verified that the MAX3185 chip is the one that is installed on this thermistor daughter board.

M308 S4 P"spi.cs0" Y"thermocouple-max31855" F60 ; configure sensor as thermocpuple
M950 H5 C"out6" T5                            ; create nozzle heater output and map it to sensor
M307 H5 B0 S1.00                              ; disable bang-bang mode for heater  and set PWM limit
M143 H5 S275                                  ; set temperature limit for heater
M563 P5 S"Thermocouple (No Heater)" H5 F0     ; define tool
G10 P5 R0 S0                                  ; set initial tool active and standby temperatures to 0C

When this config file is used, this is the result on the web interface:

This is the most common outcome as we reconfigure the firmware. There are some circumstances where the temperature shows up as "2000C" instead, usually when using another spi port.

Please let me know if there is any advice you could give to us.

Hello,

I am currently trying to find a way to read the value of the driver0.err pin after a driver error has been detected. The goal is to allow the system to run the driver-error.g macro upon the initial detection, wait 50ms, then check the status of the error input pin again in order to eliminate the chances of electrical noise causing a false driver fault (this has happened to us before).

I am struggling to find the correct object model name for the driver0.err pin. Previously, we used GPIO pins to detect driver errors. That allowed us to use a trigger to detect the error, which ran a macro that performed the second check after 50ms. We referenced this pin with the object model parameter as such:

if sensors.gpIn[6].value == 0

How might we reference the state of this pin using RRF 3.4?

My team is currently trying to access a PWM output to control a heater from the Duet 2 Ethernet mainboard. We would like to do this without using the expansion board which exposes H6 and H7 PWM outputs.

We currently do not know how to achieve this. I believe it is possible to assign the PWM fan pins to heaters, but I do not know if this may pose a risk to the hardware, or have other unintended consequences.

Is there any way that we could use the E0 and E1 extruder heaters as simple PWM outputs?

@dc42 We can't really reproduce the failure mode yet to this day. I do believe that once we transfer the board to a new ribbon cable, the problem persists. To make matters worse, the symptoms range a lot from one failure to another.

The last time this happened, there was a constant ~3V offset between H6_PWM and ground. Same with H7_PWM. However the triacs connected to this output did not activate despite this voltage difference. Which does lend some traction to the "bad ground" theory.

Could you elaborate more on what you mean by "bad ground"?

@chrishamm We are using 3.1.1 at the moment.