Sending sensors data from RPi/Arduino to Duet Dashboard?

curt.darius · 15 Jun 2021, 17:24

Hello,

I have a ToolChanger with a Duet2Wifi board running RepRap Firmware which I want to use for a process monitoring project. I need to measure the temperatures of all NEMA motors, cold end, ambient and possibly the heatbed. I also need to do vibration analysis measuring accelerations on the extruder and carriage.

I was thinking of measuring all of these using Raspberry Pi/Arduino, PT1000 sensors, ADXL345 accelerometer and somehow sending the data to the Duet2WiFi in order to integrate it into the Duet Dashboard to visualize the data. At this point I am not sure if this is possible and couldn't find any resources for what I am trying achieve.

During this research I also found out the RepRapFirmware 3.3beta3 and 3.3RC1 include experimental support for connecting LIS3DH accelerometer, so this might be a viable option. If I were to use this option, I need to know how many additional PT1000 sensors am I able to directly connect to the Duet2WiFi. Is it possible to connect 6-8 PT1000's and integrate them along with the LIS3DH accelerometer into the Duet Dashboard without having to use an Arduino or Raspberry Pi?

I would be very greatful if somebody could lead me into the right direction, thank you!

dc42 · 16 Jun 2021, 10:14

It is possible to connect the LIS3DH to the Duet WiFi via the SPI daughter board connector. However, it is intended that data is collected in short bursts only, because an accelerometer using a high sample rate produces a lot of data. If you want to measure accelerations continuously then you would be better off connecting an accelerometer to a RPi that collects and stores the data.

You can connect PT1000 sensors to any thermistor input on a Duet. The Duet WiFi has 3 built in thermistor inputs (bed_temp, e0_temp and e1_temp) and 5 more on the expansion connector. So 8 thermistor/PT100 inputs in total. If you need more sensors, you can connect up to 4 PT100 daughter boards to a Duet WiGi, each one supporting two PT100 sensors. So 8 PT100 sensors in total.

It would also be possible to connect third-party PT1000 boards that use the MAX31865 chip to the daughter board connector. To find these boards, search for "MAX32856 PT1000" on eBay, Amazon etc. Note, if a board is advertised as PT100/PT1000 and there is no option to select which at the time of ordering, then if the board comes configured for PT100 you would need to change the reference resistor to use it with PT1000.

curt.darius · 16 Jun 2021, 11:57

@dc42 Thank you for the information, I appreciate it. Is there any documentation available about what I am trying to achieve by connectng a RPi to the Duet2Wifi in order to visualize the data in the Duet Control Panel?

o_lampe · 17 Jun 2021, 05:38

@curt-darius @chrishamm
Maybe there is a way to implement "ComVisu" or similar (arduino) dashboard program as plugin for DWC?
It's availabe for RPi, too.

chrishamm · 17 Jun 2021, 05:51

@o_lampe If you can query the sensor data over HTTP (with CORS enabled on the remote endpoint), you could certainly build a plugin for it. Dynamic info panels (like the Status, Tools, and Chart areas) are planned for v3.4.

curt.darius · 17 Jun 2021, 07:09

I still haven't received a solid answer and I'm a bit confused. So there is currently no way to directly send some data from a RPi to the Duet Control Dashboard?

jay_s_uk · 17 Jun 2021, 07:14

@curt-darius unless a custom plugin is produced, correct.
You may want to look into whether BtnCmd can provide that https://github.com/MintyTrebor/BtnCmd/releases