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Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 29 Sep 2010, 17:46
by HaWe
1000 rpm -
does it mean, you can read 1000*360/60= 6000 different angle counts each second?
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 29 Sep 2010, 18:10
by gusjansson
1000 rpm -
does it mean, you can read 1000*360/60= 6000 different angle counts each second?
No... it means you can reliably get an RPM reading of up to 1000 RPM (but like I said, I believe it can actually go much higher).
The Angle sensor is a digital I2C sensor so the fastest you can read the sensor is about 100 time per second. Every time you read the sensor you can read the Angle, Accumulated Angle, and RPM. These values are all maintained in the sensor, not on the NXT. It is not like the old LEGO RCX rotation sensor or the NXT motor encoders where the processing of the encoder takes place on the p-brick.
Gus
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 29 Sep 2010, 19:32
by doc222
gusjansson wrote:What is the Max. rpm it is able to handle?
Officially the RPM range is -1000 to 1000 RPM though I have tested this well beyond that range. Gearing it up a couple of times I was able to get RPM readings beyond 6000RPM without any reason to suspect that it is not accurate.
Gus
Wow more than we should need!
Thank you,
Doc
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 29 Sep 2010, 23:12
by schodet
gusjansson wrote:The sensor packaging is really not bad or difficult to work with.
I agree about through hole version being more difficult and costly, but a packaging like a shortened version of the power function M motor would have been really easier to use.
Actually, I am dreaming of a NXT servo motor using the power function package, every time I must use a NXT motor, it is always painful to find the good way to attach it.
It is actually very interesting how this encoder works. [...]
Thanks for your response, this encoder internals looks really great!
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 29 Sep 2010, 23:48
by sqiddster
This makes me feel better about it. I agree, using the NXT motor as a rotation sensor is frustrating, has gear lag, a huge amount of resistance, and the like. I also like the ability to read the RPm and the like.
Well done, hitechnic!
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 30 Sep 2010, 03:57
by cghaning
If you are willing to build your own, a company named CUI makes an encoder that very easily is adpated to Lego use and can be through axle mounted, and also is compatible with the normal motor tachometer inputs of a motor port.
It also has a much higher resolution -- 2048 lines which if I remember correctly gives you 4096 counts per rev (Lego firmware counts rising edge of A & B pulse from encoder)
Here is the part at digi-key:
http://parts.digikey.com/1/parts/957564 ... v-kit.html
If you need further information, let me know.
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 30 Sep 2010, 05:41
by mightor
cghaning,
How would you count the pulses that quickly on the NXT? You won't be able to do without an additional controller that has interrupts.
- Xander
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 30 Sep 2010, 13:35
by milluzaj
Gus--
When are these parts shipping? How soon can I order them. The angle sensor seems really cool!
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 30 Sep 2010, 14:16
by gusjansson
When are these parts shipping? How soon can I order them. The angle sensor seems really cool!
Both the Angle sensor and Magnetic sensor are shipping now.
Gus
Re: New from HiTechnic: Angle and Magnetic Sensors
Posted: 01 Oct 2010, 00:28
by cghaning
mightor wrote:cghaning,
How would you count the pulses that quickly on the NXT? You won't be able to do without an additional controller that has interrupts.
- Xander
Xander -- I wired this encoder to the normal motor tachometer (encoder) inputs of the motor port (on the connector this is pins 5 and 6) so no external controller necessary!!!