Search found 138 matches

by elevator4
Mon Oct 20, 2014 4:53 am
Forum: AVR Microcontrollers
Topic: Too confusing to do this myself, perhaps simple for you $$$?
Replies: 2
Views: 2011

Re: Too confusing to do this myself, perhaps simple for you

Hi,
having done this before (on a different micro, and analog) I don't see any problem. You may contact me via PM.
-e
by elevator4
Thu Aug 21, 2014 4:24 pm
Forum: Projects
Topic: Long Distance Mail Notifier
Replies: 7
Views: 1039

Re: Long Distance Mail Notifier

Agree with Stevech. You may want to look at their -LR models, still sub-GHz, for longest range at a slower data rate, which I assume is of no concern in your application. As for the on/off switching, you want to wire the box so that the mailman turns it on, the Arduino latches it on until its job is...
by elevator4
Thu Nov 14, 2013 6:07 pm
Forum: PCB Design Questions
Topic: need resonator part number
Replies: 3
Views: 1398

Re: need resonator part number

Hi,
here's what i found on mouser:
http://it.mouser.com/Passive-Components ... r&FS=True

-E
by elevator4
Tue Apr 09, 2013 2:24 pm
Forum: Wireless/RF
Topic: Read data from SIGMA heart belt via wireless...?
Replies: 1
Views: 425

Re: Read data from SIGMA heart belt via wireless...?

Hi bubbolo,
Judging from the product description the protocol must substantially differ from the Polar one; must be proprietary to SIGMA, so I suggest you contact them.
by elevator4
Mon Feb 18, 2013 4:38 pm
Forum: SparkFun Product Questions
Topic: Real World Mag/Compass Sensors
Replies: 11
Views: 1087

Re: Real World Mag/Compass Sensors

fkatzenb wrote: Thoughts?
You know, I completely misread your OP. I thought you were interested in angular position only, regardless of any Z displacement. :doh: (thinking...)
by elevator4
Thu Feb 07, 2013 6:16 pm
Forum: SparkFun Product Questions
Topic: 9V switched mode power supply & relay from 110 VAC outlet.
Replies: 1
Views: 367

Re: 9V switched mode power supply & relay from 110 VAC outle

Hi,
depending on idle/peak current consumption:
through a capacitor-rectifier-zener, or a chip like power integration's ICs (www.powerint.com)
-E
by elevator4
Wed Feb 06, 2013 7:08 am
Forum: MSP Microcontrollers
Topic: PowerScope
Replies: 4
Views: 2663

Re: PowerScope

Neat!
by elevator4
Tue Feb 05, 2013 2:07 pm
Forum: SparkFun Product Questions
Topic: Real World Mag/Compass Sensors
Replies: 11
Views: 1087

Re: Real World Mag/Compass Sensors

Hi, I assumed the magnet was never going to be 100% perpendicular. You can also do it with discrete components: An LC relaxation oscillator, frequency changes with field force. At any rate, at some point I'd do some real-hardware testing. Check these out (unfortunately, "coming soon"): http://www.al...
by elevator4
Fri Feb 01, 2013 5:40 pm
Forum: SparkFun Product Questions
Topic: Real World Mag/Compass Sensors
Replies: 11
Views: 1087

Re: Real World Mag/Compass Sensors

Frank, assuming your sensors are able to resolve both field polarities, two (X and Y) would suffice. Imagine rotating the sleeve through 360 egrees: The X sensor will give you a reading proportional to cos(angle), while the Y will give you sin(angle). by these two measures (the relation between the ...
by elevator4
Tue Jan 29, 2013 4:43 pm
Forum: SparkFun Product Questions
Topic: Capacitor as a timer
Replies: 2
Views: 444

Re: Capacitor as a timer

Hi,
here's a nice page on calculating the required capacitor given current draw and time-to-discharge. Enjoy,
-E
http://www.elna.co.jp/en/capacitor/doub ... ation.html
by elevator4
Tue Jan 29, 2013 4:38 pm
Forum: Arduino
Topic: Can't find an answer
Replies: 4
Views: 536

Re: Can't find an answer

Hi, You can always try :) but to somewhat level out the differences in Vf I would at least use (for an 8x8 matrix) 8 resistors at the cathodes and 8 at the anodes, then tie all the cathode R's together, same for the Anode's. Calculate the Rs to provide current for 8 parallel LEDs each (eg 20mA*8=160...
by elevator4
Tue Jan 29, 2013 1:51 pm
Forum: Wireless/RF
Topic: headphone wire into wireless
Replies: 1
Views: 342

Re: headphone wire into wireless

Hi, if you are looking for a small form factor (read small batteries), nothing beats FM radio. Unfortunately, in the past cheap transmitters (most were based on a crappy transmitter IC from Holtek) have given the solution a bad name. More recently however, ICs have been developed with far better sou...
by elevator4
Thu Jan 24, 2013 2:59 pm
Forum: PCB Design Questions
Topic: power rail help
Replies: 8
Views: 1246

Re: power rail help

The p-fet should work. What sort of isolation are you looking for?
There are also ICs for the purpose, eg TI TPS2111
-E
by elevator4
Thu Jan 24, 2013 7:06 am
Forum: SparkFun Product Questions
Topic: Trying to make a tiny, wearable, simple button to log data
Replies: 5
Views: 524

Re: Trying to make a tiny, wearable, simple button to log da

Wow, that would be really great! Please let me know how much you want for one? I don't know. I'm more concerned with the development setup you'd need. Here's what I am using: - the final coin battery is not mounted on the logger at that stage: first, to allow measuring current draw. Second, to save...