Coming soon: Accelerometer Support

zapta · 10 Apr 2021, 17:37

@cncmodeller said in Coming soon: Accelerometer Support:

delivery from Germany to the UK is prohibitive for just one board.

There are inexpensive alternative with SAMD21G18. Will they work?

E.g.

https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=SAMD21G18&_sacat=0

CNCModeller · 4 Oct 2021, 19:07

@zapta said in Coming soon: Accelerometer Support:

@cncmodeller said in Coming soon: Accelerometer Support:

delivery from Germany to the UK is prohibitive for just one board.

There are inexpensive alternative with SAMD21G18. Will they work?

E.g.

https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=SAMD21G18&_sacat=0

Unfortunately it looks lot me that they don't have a CAN interface... And even if they did I doubt the pinout would be compatible with @dc42 s firmware

I do have a teensy 3.2 with CAN but I'm assuming a transcode to that board is a massive task, even if it's fast enough.

zapta · 4 Oct 2021, 19:59

@cncmodeller said in Coming soon: Accelerometer Support:

Unfortunately it looks lot me that they don't have a CAN interface.

I see, the CAN transceiver are external to the MCU.

Edit: In this case, an external CAN transceiver may help. E.g. https://www.aliexpress.com/item/32375462280.html

CNCModeller · 10 Apr 2021, 20:29

@zapta said in Coming soon: Accelerometer Support:

@cncmodeller said in Coming soon: Accelerometer Support:

Unfortunately it looks lot me that they don't have a CAN interface.

I see, the CAN transceiver are external to the MCU.

Edit: In this case, an external CAN transceiver may help. E.g. https://www.aliexpress.com/item/32375462280.html

In principle yes if it's the right CAN standard, but it'll require new pin allocations in the firmware and TBH I'm not that interested in reworking @dc42 code.

I'm more interested in standing on the shoulders of giants than trying to be one lol.

zapta · 10 Apr 2021, 20:38

@cncmodeller, let your inner giant free.

wildblue · 4 Nov 2021, 13:39

@dc42 Okay, a LIS3DSH Sensor is ordered to connect via SPI on my Duet2wifi.

As i understand, the LIS3DSH should be also supported, because its only a more capable version of the LIS3DH. If not, there it goes to my bin of parts and 1.60€ down to the gods of tinkering. Just using the second position of this order (a true and only supported LIS3DH) then.

Just for planing things ahead, when will Version 3.3b3 be released?

I would love to add CAN-bus connectivity to my machine with Duet2 hardware. Is there yet a viable path to go for people capable of soldering and willing to tinker with their hardware?

dc42 · 4 Nov 2021, 15:37

@wildblue said in Coming soon: Accelerometer Support:

As i understand, the LIS3DSH should be also supported, because its only a more capable version of the LIS3DH. If not, there it goes to my bin of parts and 1.60€ down to the gods of tinkering. Just using the second position of this order (a true and only supported LIS3DH) then.

Unfortunately the LIS3DSH is not backwards-compatible with the LIS3DH, so the current firmware will not work with it. The control registers are mostly different, although the output and status registers are the same. So firmware changes would be needed to support it.

Just for planing things ahead, when will Version 3.3b3 be released?

As soon as I find a fix for the ADC/DMA issue in the Duet 3 Mini.

I would love to add CAN-bus connectivity to my machine with Duet2 hardware. Is there yet a viable path to go for people capable of soldering and willing to tinker with their hardware?

Unfortunately the SAM4E8E MCU on Duet 2 supports only basic CAN, not CAN-FD; so no. Even if it did, it has insufficient flash memory and RAM.

Nuramori · 13 Apr 2021, 06:45

@dc42 can you share a quick diagram how you would wire up the LIS3DH with a toolboard? I have a duet3, and it's directly wired to a 1.0 toolboard right now (on the printhead). If I were to add the accelerometer, from what I am reading I need a sammyc21 also, but that all can reside on the printhead, but I'm not clear how it would chain up. I understand that the one side of the toolboard is terminated with the r120, so would that be removed and the sammyc21 put in the chain, with a termination after that?

Nuramori · 13 Apr 2021, 06:51

@dc42 one other question, for the direct connection method, where you say to connect it to the SPI daughterboard, via MISO and MOSI. I noticed that the temp daughterboard connector also has SPI0_MISO and SPI0_MOSI connections - does that mean those could be used, AND also still connect a SBC, which has SPI1_MISO and SPI1_MOSI?

dc42 · 13 Apr 2021, 20:57

@nuramori said in Coming soon: Accelerometer Support:

I understand that the one side of the toolboard is terminated with the r120, so would that be removed and the sammyc21 put in the chain, with a termination after that?

Yes; or alternatively, connect the SAMMYC21 between the main board and the tool board, so that the termination resistor is still at the end of the chain. Or, if the SAMMYC21 is on the tool head so the wires between it and the tool board are short, just connect the SAMMYC21 CAN pins in parallel with the tool board CAN pins.

dc42 · 13 Apr 2021, 20:59

@nuramori said in Coming soon: Accelerometer Support:

@dc42 one other question, for the direct connection method, where you say to connect it to the SPI daughterboard, via MISO and MOSI. I noticed that the temp daughterboard connector also has SPI0_MISO and SPI0_MOSI connections - does that mean those could be used, AND also still connect a SBC, which has SPI1_MISO and SPI1_MOSI?

Yes, use the temp daughterboard connector to connect an accelerometer directly. The SBC uses a separate SPI bus. However, currently accelerometer data can only be saved to file when running in standalone mode.

Nuramori · 13 Apr 2021, 23:02

@dc42 can the sbc still function,, as in, can I use the plugin to see the data, even if it’s not being saved?

jay_s_uk · 14 Apr 2021, 05:05

@nuramori unless DSF has been updated to include accelerometer support, no

Nuramori · 14 Apr 2021, 07:00

@jay_s_uk rats.

I'm designing the mount for the accelerometer, and now I'm trying to understand the "Inn" orientation parameter for M955. It's not quite clear how to determine the correct value. I have a core xy (BLV cube) and I'm looking to orient the board 90 degrees from what the board symbol shows, which would otherwise align with the printer x/y axis. So if the "default" is 21, I'm not sure what it would be if I rotated the board clockwise 90 degrees.

dc42 · 14 Apr 2021, 10:11

@nuramori, the documentation was wrong. The default (which corresponds to the chip axes lining up with the machine axes) is 20, not 21.

When you rotate the chip, if chip +Z is still up then the first digit 2 doesn't change. The second digit will be 1 if the chip +X direction faces the machine +Y direction, or 5 if it faces machine -Y.

Nuramori · 14 Apr 2021, 10:40

@dc42 aaaah, I get it now, thanks! The silkscreen arrow on the adafruit board helps put that together.

zapta · 15 Apr 2021, 03:43

@nuramori said in Coming soon: Accelerometer Support:

I'm designing the mount for the accelerometer..

Is the accelerometer supposed to be mounted permanently or just used one time to measure the reassurance frequency(s) of the system?

Nuramori · 15 Apr 2021, 05:57

@zapta My understanding it's providing real time or near real time feedback that's taken into account for all movement. So in short, a permanent part of the system.

jay_s_uk · 15 Apr 2021, 06:02

@nuramori on klipper its a run once and remove from the system thing until you change something.
not sure if it will be used in the same way here or not

CNCModeller · 15 Apr 2021, 07:32

@jay_s_uk said in Coming soon: Accelerometer Support:

@nuramori on klipper its a run once and remove from the system thing until you change something.
not sure if it will be used in the same way here or not

My understanding is also that it's a run once to characterise the resonance of the printer.

Input shaping is an open loop approach as far as I understand.

However, the accelerometer needs to be rigidly secured to the print head to accurately measure the printers characteristics so a dedicated mount IMO is a good idea.

That's not to say we won't find other uses for an accelerometer in the the future of course!!