SparkFun Forums

[rgbphil]

Ivensense are apparently releasing their new IXS series gyros, giving pitch (X) and yaw (Z) angular rate sensors (aka gyro) in 500 deg/s and 2000 deg/s specs. Supposedly destined for Wiimote Motion Plus adapters.

Also being released are single axis Z sensors (ISZ range).
This means with two IXS sensors, or an IDG+ISZ along with a tri axis accelerometer you've got a 6DOF IMU without naffing around with vertical mounted boards.....huzzah!!

No word on pricing yet, can the good people at Sparkfun have a look into a bulk purchase and put them on the site please? (also include single chips for those of us who don't want to use breakout boards).

While you at it Sparkfun, is there another shipment of the ADXL345 accelerometer chips coming in soon? (the cool ones with SPI i/f and FIFO buffer).

[Fredjikrang]

I agree! A new 6DOF IMU with an IDG-500, and an ISZ-500 would be amazing! I bet it would cost about the same, or even less, than the current Atomic IMU, because it could all be done on a single PCB, and it would be a lot better, as the Invensense gyros are quite a bit nicer than the LISYL gyros.

[rgbphil]

I must admit, I haven't any experience with angular rate sensors (I prefer to be pedantic and not call them gyros....just me). Been waiting to dip my toes in before committing.

Can you elaborate on how the Invensense sensors are better?

I think the best thing about the IXZ sensors coming out is they're being used in a mass market device like the Wiimote, this should ram down the price like the original wiimote did for the ADXL330.

Until they cheaply integrate XYZ onto one chip, does anyone know of people utilising the fact that putting several multi axis sensors chips on a board can potentially give more information. For example with the IDG500+IXZ500 you've got two X, two Y and one Z axis. With two IXZ units you've got two Z axis, possibly an extra horizontal axis if you offset the sensors rather than align them....surely this extra information can be useful if the sensors are placed a distance from each other.

The next on the wish list for MEMs sensors are internal AD sampling and big FIFO buffers with multiple triggering to take the load off a micro. The ADXL345 I mentioned is almost there with 32 samples, I'd like 64 or 128 sample FIFOs though to get a good 'before' snap shot of an event.

Phil

[corvette123]

huh?

u say sparkfun has adxl 345's???

they arent out till june-ish except for samples according to the major distributors and analog.com

but sample away! just a phone call away.

yah its gonna be a nice accelo.

if you guys wanna try out the IDG line of sensors already done on a module for you with low noise VREG and op amp buffering, +filtering, stop by us and checkout our offerings

www.thesiliconhorizon.com

we offer 440/2000/67 deg / sec flavors.

yes our IDG 650 has solder bridges to change between 440 and 2000.

stop on by.

[Fredjikrang]

I must admit, I haven't any experience with angular rate sensors (I prefer to be pedantic and not call them gyros....just me). Been waiting to dip my toes in before committing.

Can you elaborate on how the Invensense sensors are better?

I'm not sure why it is, but the IDG gyros just work better. I've mostly seen them used on quadrotors, and there has been a lot of trouble trying to get the LISYL gyros to work for quadrotors, because of their low cost, but they tend to have strange issues and drift a lot.

One of the best theories as to why this is the case is because of the LISYL's low resonant frequency, operating at about 4.5Khz, while the Invensense operate at about 26 Khz.

The Invensense gyros also have dual outputs, an onboard temperature sensor for calibration, a faster startup time, and really don't cost all that much more per axis (you can buy them straight from the manufacturer for only $40 for the dual axis chips.) They still cost almost twice what the LISYL gyros do per axis, but you don't have to use as many external components per axis, and have to make fewer PCBs as well (for an IMU type setting.)

[gchristopher]

I wonder if there's any chance of the IDG-500/650, ISZ-500/650 and IME-3000 accelerometer set becoming available on Sparkfun? Seems like that's the combined application InvenSense intends for their 6 axis setup.

[corvette123]

I sincerely hope so!!!

i dont think theyve done a new IMU in a while...

we are gearing up to do a new one to replace our IDG 300 based IMU too....

may be ARM9 based running linux ala 200 MIPS (and do other things too obviously...)

or a TI part...

not sure yet.

[Fredjikrang]

Sparkfun has done a few new IMU's in the last few months, but I think that they are still waiting on the ISZ's at least for this new IMU, though it wouldn't surprise me if they waited for the new accel as well.

That would be one sweet combo, and very small and inexpensive too! A great replacement for the 5 DOF IMU they currently sell.

[corvette123]

too bad the ADXL345 aint 16 bits.

now that would be suuhhhweeetttt

[corvette123]

oh yah the Atomic!!

nice and cheap

[Fredjikrang]

It just keeps getting more interesting!

Invensense just cut the price of all their gyros in half. An IDG500 now only costs $20 straight from them.

[corvette123]

that is always nice!!

we have passed the price cut on to our customers.

and yes we carry the new IXZ modules right now too.