Reply with Quotehttp://www.youtube.com/watch?v=ARyiSqxUvbw&feature=player_embedded]Z-DRIVE Linear Motion - YouTube
they makes toys with that , this mean it's cheap !
http://www.google.com/url?sa=t&rct=j...SZ4j-ZKiQY810g
This is the PDF of the calculation of a printed circuit to create a multipolar magnetic field !
This is the solution by creating a printed circuit it become easy to go beyond the limit of 1mm pôle and also very easy to make specific off center circuits!
The guy that refuse to give me a magnet will regret it now, but those of austria microsystème will not regrets the 3 samples they give me!
I try to find someone that can calculate the shape of the printed circuit (hey young engineer of austria that is work for you) i forgot my math too long time ago !
http://www.youtube.com/watch?v=ARyiSqxUvbw&feature=player_embedded]Z-DRIVE Linear Motion - YouTube
they makes toys with that , this mean it's cheap !
Is there any point in going with a finer pole resolution? I had the impression that the 1 mm pitch was determined by the placement of the hall sensors inside the AS5311.
The problem is the magnet , making multipole magnet smaller than 1 mm seems very difficult
But making a detector smaller should not be a problem at all !
I manage to weld it and all the connections are good . This is definitely a hard job for a guy of 57 !
I will start my test soon now !
The good i finished the board I put all the led i check my 5 V I put a crocodile on the ground usually i use a much smaller clips but it's so messy in my lab !!!
Go ! smoke ! merde,skata **** ostia !
I just burn my as5311 !
so we manage to engrave a tiny circuit with a machine of 1,5 tons making a special tool with a old german tool profiler , I lost time to make a solidwork schedule train for balling finally i manage to weld the circuit and I burn it!
I was really disappointed, specially because this was a mistake of beginner(the crocodile make a short circuit) so i try to desolder it and it work !
I resold it , this time i did not use crocodile (guess why ?)
I make my test and it work, now i must find the good magnet and test different electro magnet !
I have found a little magnet to test the as5311 in rotary mode!
I must say that the quality of the magnet and the quality of the implementation is VERY important.
I am used to optical encoder so i can feel the reaction of an encoder. An approximative implementation make this encoder useless since the steps become uneven.
to be fair an optical encoder misaligned will not work properly and worst may break(this cannot happen with magnetic encoder) !
except that the signal is clean. But there is no way to make proper test if i do not make a clean implementation , I just can say it has a strong willing to work ! LOL
Did you get the proper magnet strip from Austrian Micro along with your AS5311 eval?
I did not ask for it and I see now that it is a mistake since I miss a reference to find alternative cheaper solutions.Originally Posted by scsi
but as a rotary encoder it work pretty well, I consider that before you become familiar with this circuit you get an "ideal" magnet sampler even if it seems that the chips adapt itself pretty well.
Of course if you are very familiar with magnets it's pointless since the technical specifications of the magnet are meaningful for you but it's far to be my case
They can send you one 300mm sample free of charge: AS5000-MS10-300 / Magnets / Magnetic Encoders / Products / Home - austriamicrosystems AG
Getting longer continuous pieces will be a major challenge though. I'm unable to find a reasonable retailer who sells high quality scales. Bogen (OEM) will sell in 25m reels, but that will run you around $1,500.
the high précision magnet is not send in roll since it will create variations in legth.
I will try to see if it's possible to create electro magnet for this because the precision will be then much better!
I really depends on how precise you want it to be. They send strips in rolls and able to maintain 10um per meter accuracy just fine because the rubber magnet is bonded to a 0.3mm stainless steel base tape, which maintains shape pretty well. They can also do better than 10um/m, but then they have to magnetize a strip that is already bonded to a rigid base.
Hi,
I have tested the AS5311 with a AS5000-MR10-128 MagRing from Austrian Micro and I can say that the AS5311 generates a loot of noise on the A and B incremental outputs.
I used a STM32F2 MCU to read the incremental outputs and can’t get a clean reading even with the STM32F2 digital filter engaged (the STM32F2 can use a programmed digital filter on the input capture IOs), even with the magnet standing still over the AS5311 the noise in the incremental outputs makes the STM32F2 encoder interface count up and down erratically as if the mag-ring was moving back and forward.
So, if you want to use the AS5311 get prepared to make a analogic filter on the board…
Regards
PA
How long is your transmission line? What VDD level are you using? Have you tried to terminate the A/B lines with resistors?
I'm getting noise only when magnetic field is not strong enough (>0.3mm gap), which may be your problem with the wheel.
The mechanical implemenation must be done with care Astropor what is the accuracy of your implementation ?
Hi again,
Yap, there is a 100ohms series resistor at the source do match the impedance of my line, the gap between the chip and the mag-ring is about 0,6mm.
There is no ringing on the line, no reflections due to mismatch impedance, the only problem is to much "glitch" ... the datasheet does mention a 0,3 to 0,6 gap ... I'm going to try a shorter gap and will report.
Regards,
PA
Re: AS5311 encoder 2 µ for VERY little money
Bogey USA has a new point of presence. I spoke with the rep who was quite happy to get some 1m pieces for $30-40/M in from Germany.
I'm going to give this a try.
Nitrous
Re: AS5311 encoder 2 µ for VERY little money
These will provide 2um of resolution, I doubt they will provide better than 20-40um accuracy though, and this is dependent on the magnetic tape manufacturing processes.
Re: AS5311 encoder 2 µ for VERY little money
Interestingly, Tooling, parts, and accessories for bench top machinists - LittleMachineShop.com has 1 meter length magnetic scales on for $39. The counts per inch is 5080 so that would seem to be the spec for 5 micron accuracy.
Nitrous
