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31  Using Arduino / General Electronics / Re: 23K256 SRAM Issues (SOLVED) on: February 23, 2013, 11:54:54 am
For anyone struggling with this, here is how I solved it:

Used the following components and wire routing:
(1) Arduino Uno
(2) Microchip 23K256
(3) SparkFun Logic Level Converter (BOB08745)
(4) 10K Resistor

Code:
Arduino--Logic Conv--23K256
D13------TXH/TXL-----SCK
D12------------------MISO
D11------TXH/TXL-----MOSI
D10------------------CS
3V3------LV
5V-------HV
GND------HV GND------VSS
3V3------------------HOLD
3V3------[10KR]------CS

Please note, no cats were harmed during the entirety of this experiment.
32  Using Arduino / General Electronics / Re: 23K256 SRAM Issues on: February 23, 2013, 01:53:49 am
I think we're on to something here. Let me release this cat and try an experiment. I'll report back...
33  Using Arduino / General Electronics / Re: 23K256 SRAM Issues on: February 22, 2013, 10:58:58 pm
I powered the chips off the arduino 3v3 pin and ran CS, SI and SCK thru a spark fun Logic Level Shifter (and also ran them thru an adafruit nxp0108 breakout board). I tired using 1k8/3k3 R voltage dividers too and with and without a pullup on CS. I get data out of the chip, but its gibberish. Thx.
34  Using Arduino / General Electronics / 23K256 SRAM Issues [solved] on: February 22, 2013, 08:12:53 pm
 I’ve spent the better part of 2 days attempting to get SPI 23K256 RAM chips to communicate with an arduino. I’ve tried 3 arduino boards (168, 328 & uno), two 23K256 chips, wired them with and without voltage dividers and logic level shifters.

I’ve tried several SPI and SPISRAM libraries found on the internet.

I’ve also read countless reports of others having similar issues and come to the conclusion these chips hate me. I view anyone claiming they've made this work skeptically.

At this point I'm contemplating sacrificing animals to the God of Peripheral Interfaces. For the sake of stray neighborhood cats, any advice would be appreciated.
35  Using Arduino / Programming Questions / Re: GPS direction/ distance problems on: February 17, 2013, 08:39:07 pm
Quote
You could be travelling backwards, looking toward your original location, but the GPS would not know this, it would display you moving toward your destination.
No, it wouldn't. It would show a vector moving away from the target. Now, it would not know, or care, which way you are facing, or whether you are moving in the direction you are facing, or not. All it knows is which way you are moving.

+1
36  Using Arduino / Programming Questions / Re: GPS direction/ distance problems on: February 17, 2013, 10:19:36 am
Distance is in NM, so .01 = 60 feet, either GPS is not updating (indoors?) or try a destination that is closer.
37  Using Arduino / Sensors / Re: Calculating Vehicle Position with an IMU on: February 11, 2013, 12:57:11 pm
I had an old Stack data acquisition unit for my kart.  Thing is probably 10 years old or older now.  It had an accelerometer in it which it used to derive track maps.  This was a long time ago, and it didn't use a gyro or magnetometer, just an accelerometer.  The track maps visually looked very accurate, although I can't say exactly how accurate, and to scale they were, but visually it did a very good job.  Accelerometer data is very noisy, so if you are just integrating the raw data, I would imagine the results to be awful.  You are going to want to use some form of complimentary filter or Kalman filter to integrate to determine your position.

Reasonable track maps can be derived from accelerometer AND a wheel speed sensor. However, remember this is also on a track and typically defined over several lap iterations.
38  Using Arduino / Programming Questions / Re: LATLONG 2 UTM/MGRS library for Arduino? on: January 04, 2013, 11:35:02 am
is there an Arduino library that can convert LatLong data from a GPS to UTM or MGRS strings? Google didn't find anything useable.

Doubtful, I just looked at some old LL to UTM conversion code of mine and it takes up 12000 bytes. Conversion to/from MGRS would probably exceed 16000 bytes.
39  Using Arduino / Programming Questions / Re: Need help with Chess Algorithm for Arduino. on: December 18, 2012, 09:43:00 pm
Google Avr-Max or micro-max
40  Using Arduino / Programming Questions / Re: delayMicroseconds(0) = 16383µs on: December 06, 2012, 10:42:38 am
Sidetrack:

Why is anyone calling delayMicroseconds(0) in the first place?
41  Using Arduino / Project Guidance / Re: Vehicle Keyless Proximity Remote on: December 02, 2012, 04:43:39 pm
Great point, maybe there is some sort of prevention already built in (?).
42  Using Arduino / Project Guidance / Vehicle Keyless Proximity Remote on: December 02, 2012, 02:55:10 pm
I saw a Ford advertisement where a vehicle’s trunk is openned by swiping a foot under the rear bumper. I like that feature.

My car has a keyless proximity remote, and so I think this would be a possible project. Do you think I could use an arduino with proximity sensor and tap into the electric trunk switch to get the same result?

Any thoughts would be welcome.
43  Using Arduino / Programming Questions / Re: Speed of floating point operations on: November 08, 2012, 10:39:55 am
What he said.

http://ucexperiment.wordpress.com/2012/10/30/arduino-timing-failure/
44  Using Arduino / Programming Questions / Re: Can I send a serial GPS data up to 10Hz from 1Hz GPS receiver? on: November 05, 2012, 09:10:23 pm
You might find something here useful:

http://ucexperiment.wordpress.com/2012/03/13/arduino-scripted-gps-simulator-v2-0/
45  Using Arduino / Programming Questions / Re: Need a math sketch to compare Teensy 3.0 to Uno on: October 14, 2012, 10:16:33 pm
what cpu spedd was the T3.0 running at?
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