Show Posts
Pages: 1 ... 4 5 [6] 7
76  Using Arduino / General Electronics / Re: LED Driver for 8x8 Display on: March 16, 2012, 06:48:20 pm
I need to be able to see the display some distance away, maybe 10m or so.
77  Using Arduino / General Electronics / Alternative to MAX7219 LED Driver for 8x8 Display on: March 16, 2012, 06:25:43 pm
Hi

Is there a cost effective alternative to the Max7219/21 LED driver ?
They are about $23 each at Element14

Is the Texas TLC5928 compatible, it doesn't say anything about SPI, just serial connected.

My electronics skills are not good enough to determine if this would work

I'm driving a 8x8 display via SPI bus, well hoping to  smiley

K
78  Using Arduino / Programming Questions / Re: Arduino calculation problem on: January 03, 2012, 10:10:16 pm
Can you please explain to me how an integer has decimal points ?
and how to divide 2 16bit ints and get a decimal point
79  Using Arduino / Programming Questions / Re: Arduino calculation problem on: January 03, 2012, 04:40:52 am
or go (240 x 100)/280
an int goes from -32,768 to 32,767, so you should just sneak in.

Still will only be an approx answer, but might be okay for your needs
80  Using Arduino / Programming Questions / Re: Arduino calculation problem on: January 03, 2012, 04:04:59 am
change your data type to Float.
Int does only hold whole numbers
81  Using Arduino / Programming Questions / Re: Semaphores on: January 02, 2012, 01:33:24 pm
I have been using Splat controller for quite a while. www.splatco.com.au
They have a very simple cooperative OS with semaphores.

Quite a bit of free downloadable material their site.

Anyway, this is my first C program, so there is quite a bit of syntax learning to be had.

I'm using Protothread as my "OS" as it appears to be nice and simple (AND completely in C) and I'm just doing a bunch of tasks doing different things to get my head around C.
As I have an Duemilanove (8bit) and Chipkit Max32 (Pic32 bit) board, I can have the same program running on both.  :-)

Task1 is just the blinking LED, task2 is button press with LED on using bit(), task3 is a star delta motor starter, task4 to task8 to be decided.
Trying to use all the Protothread timing functions to understand them.

Cheers
K

82  Using Arduino / Programming Questions / Re: Semaphores on: January 02, 2012, 04:22:31 am
Oops, yes they are. Unsigned long then.

Couple of reason.
I find it much easier to remember names and the code is usually easier to read when using labels.

Also by using 32bits, it fits my inputs very nicely as i have 32 inputs per channel and 3 channels.

This makes comparisons and bitwise stuff easier.

K
83  Using Arduino / Programming Questions / Re: Semaphores on: January 02, 2012, 04:08:35 am
I'm obviously missing something here :-), not first time.

So, how would I normally declare a bunch of semaphore ?
Can I use an unsigned int, ie 32bit, and declare semaphores from 0 to 31 using labels ?

I see its quite easy to set and clear them using bit() or bitset() etc

Cheers
84  Using Arduino / Programming Questions / Semaphores on: January 02, 2012, 03:23:21 am
I want to use 1 bit semaphores for communicating between tasks.
I have searched the site but everything points to semaphores using quite advanced RTOS, which I don't need.

Is there not some sort of framework for using semaphores in Arduino ?

I use Protothread as my cooperative "operating system"

K
85  Using Arduino / Programming Questions / Solved: Re: How to shuffle 8 inputs into a byte on: January 01, 2012, 07:29:25 pm
Primo. Thanks a lot as I hadn't seen those byte instructions.
K
86  Using Arduino / Programming Questions / Solved: How to shuffle 8 inputs into a byte on: January 01, 2012, 06:18:53 pm
I have been trawling the site, but to no avail. Maybe I'm searching the wrong thing.

Anyway, I want to take 8 inputs and put theses into a byte.
The inputs will be from different ports, so i cannot just read a port.

Input 1 to go into lsb or bit 0

I can do a digitalRead(pinX) but how do I get input information into a specific bit in the byte

Cheers and happy new year :-)

K
87  Using Arduino / Programming Questions / Re: Usimg millis() as a global timer on: December 27, 2011, 05:43:53 pm
I did search the site, but obviuosly not deep enough :-)

Found the answer here
http://www.arduino.cc/playground/Code/TimingRollover

Cheers
K
88  Using Arduino / Programming Questions / Usimg millis() as a global timer on: December 27, 2011, 02:45:24 pm
I want to use millis() as a global timer, however when it rolls over to zero, how do I handle that ?


Cheers
K
89  Using Arduino / Motors, Mechanics, and Power / Re: Hysteresis Current Control on: December 10, 2011, 01:31:02 am
Freescale, Texas and MicroChip, among others, have a significant amount of application notes on their web sites relating to vector drives and their applications.
Arduino should be fast enough for simple speed control and proof of design.

Once you go further you will need DSP/32bit to do real time calculations.
BTW you can get 32bit arduino (PIC32) boards :-)

K
90  Using Arduino / Programming Questions / Re: Simple Scheduler on: November 27, 2011, 03:37:43 am
Cool

Thanks

fiddler
Pages: 1 ... 4 5 [6] 7