Coming soon: Accelerometer Support

CNCModeller

@o_lampe said in Coming soon: Accelerometer Support:

@cncmodeller
Imagine we'd have to terminate all unused I/O pins on the boards

As I understand it there is a difference between unused pins and unterminated flying wires that are still connected. Unterminated wires would just act as an antenna to draw electromagnetic interference into the Duet.

dc42

@o_lampe said in Coming soon: Accelerometer Support:

@cncmodeller
Imagine we'd have to terminate all unused I/O pins on the boards

No need.

Nuramori

@cncmodeller given my liquid cooled head which is not what I’d call light, the 2-5 grams I’m adding is t something I’m going to fuss over, and I plan on just leaving it on the head. I have a toolboard on the back of the print head, so the wiring is short and sweet.

aprz

@nuramori said in Coming soon: Accelerometer Support:

@aprz This is how/where I'm mounting mine...

I like your cooling system.

zapta

@cncmodeller, looking at your picture, the accelerometer is close to the rail and far from the nozzle. I would think that you want to measure the accelerations of the nozzle which can be different due to mechanical flex and play.

(I am not an expert, just speculating).

CNCModeller

@zapta Hi it's not my printer its @aprz

But as the print head is pretty much a solid item i'd think it won't really matter. Most if not all of the flex in the printer and hence the source of resonance is in the structure and drive system in my opinion.

zapta

@cncmodeller, that would something interesting to try, the effect of the position of the accelerometer on the measurement results.

BTW, as for same uniform accelerations on a stiff object, you don't want to be near the bow of the ship when the sea is rough.

arhi

@zapta said in Coming soon: Accelerometer Support:

I would think that you want to measure the accelerations of the nozzle which can be different due to mechanical flex and play.

that's why I really like the klipper idea of using el-cheapo ADXL345 board (0.74EUR + free shipping on all for e.g.) is like 2 gramms, you can stick it directly to your nozzle with some double tape (or very close to it)

on the other side LIS3DH that is (will be) used with RRF (I understand why, it is a better chip IMHO) is zero stock on digikey, mouser .... now I do have some LIS3DH too and they are great as they can send bigger chunks of data if I remember correctly but I really hate they are not on stock at any of my suppliers and that all the boards I have it on (and that I can buy it on) are 4-5 times bigger than small boards ADXL345 comes on

@o_lampe copter needs a kalman so as many sensors as you can pull to work together to get to proper data. here you are interested in very short and very simple measurement so no need for additional sensors..

with a growing flat spot on a ball

for this you normally need a very different accelerometer probe and they cannot be mounted on the hotend but on the rail ... this equipment that detect balls that are starting to deteriorate start, used, at a price of a good brand name printer ... el cheapo accelerometer attached to a plastic carriage will not be detecting a flat spot on a ball in the bearing

zapta

@arhi said in Coming soon: Accelerometer Support:

zero stock on digikey, mouser

There is a global shortage of semiconductors due to the pandemic and the components that are still available went up in price.

"First they came for the toilet paper and I didn't speak up, then they came for the accelerometers".

arhi

@zapta makes sense ... I just yesterday paid 2300eur for gpu that was below 1000$ when it was released crazy world

I have some of the LIS3DH in stock at home, never tried them tbh so good reason to do so now

o_lampe

@arhi said in Coming soon: Accelerometer Support:

I just yesterday paid 2300eur for gpu

Mining for Crypto-cash? I have a 64CPU-cluster I wanted to use for mining, but never got it working...damn Linux

wildblue

My ordered sensors just came in today from china. Even better, the new firmware is also available right now.

@dc42 Before soldering a header to the breakout board, i would love to know If the analog inputs of the sensor will be available in reprap firmware. Just like the panelDue we have available inputs for free at no additional cost (other
than you implementing the code to make then work) on our remote devices, which i already have plenty ideas of what crazy stuff we could connect to them.

So please let ne know If you also have the future of what DuetFirnware could become in mind and If the analog! inputs are/will be available via gcode.

dc42

@wildblue I don't have any plans to support the analog inputs at present.

j3d

@dc42 said in [Coming soon: Accelerometer Support]

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.

Will this still work if you have a temperature daughterboard installed? I'm utilizing the thermocouple board on a Mini 5+.

dc42

@j3d said in Coming soon: Accelerometer Support:

@dc42 said in [Coming soon: Accelerometer Support]

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.

Will this still work if you have a temperature daughterboard installed? I'm utilizing the thermocouple board on a Mini 5+.

Yes, but as described in the wiki page the CD and INT pins of the accelerometer must be connected to one of the IO ports.

zapta

Apropos accelerometers mounted on 3D printer gantries, this guy uses an Android accelerometer app to measure fan vibrations and fixes it by balancing the fan with a small piece of adhesive tape.

https://www.youtube.com/watch?v=ZZ3SxrUpCnM

keyz182

Does anyone know if the accelerometer can be wired to a Toolboard? I ordered one over the weekend from Ooznet (UK) - so assuming it'll be a v1.0 not v1.1. Would make things a bit easier

Nuramori

@keyz182 you can, using a sammy-c21 in conjunction with it.

keyz182

@nuramori So no direct connection, it'll have to be via a SammyC21 on the CAN bus? Should have waited for v1.1 to be in stock lol. Ah well, I'm sure I'll find other uses for a Sammy 21.

At least I can stick with just the 4 wires to the tool

Nuramori

@keyz182 correct. I had prepped just such a set up days before the announcement of the 1.1 toolboard. I've since relegated the part to the "maybe some other project" bin.
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