Prop Magazine - April 2008

last issue March 2008 next issue May 2008

Ramblings by the editor

Well, this is the 3rd edition of Prop Magazine. It won't be that long and it will be time for an anniversary. Speaking of anniversaries, this must be about the 2nd anniversary of the Propeller Chip (If someone knows the exact date can they drop a note in this thread please). So, I have decided to include some of the old posts in this edition. On a more recent note there have been a fair few object releases this month. Check out the new games, I2C slave, nice user interface on the Quad DRO and the others listed below.

The ESC was also this month and some of the people from Parallax were there. Check out their reports below. Also on show was the Coyote-1 and the danceBot.

History

A miracle chip? http://forums.parallax.com/forums/default.aspx?f=25&m=110889

FullDuplexSerial is posted. Probably the most widely used object. http://forums.parallax.com/forums/default.aspx?f=25&m=111614

Some early notes about the propeller. http://forums.parallax.com/forums/default.aspx?f=25&m=113461

Propeller Guts - Some early documentation. Still helpful although most things are now in the manual and data sheet. http://forums.parallax.com/forums/default.aspx?f=25&m=111215

Special Threads

Being April there were of course a couple of special threads. First up was the release of the Relleporp. http://forums.parallax.com/forums/default.aspx?f=25&m=261265&g=261647#m261647

And secondly a hidden assembly instruction was found! http://forums.parallax.com/forums/default.aspx?f=25&m=261282

Basics

Request for programs to put in a kiosk program for ESC (with any luck they will release what they used, get the hint?) http://forums.parallax.com/forums/default.aspx?f=25&p=1&m=262904 http://forums.parallax.com/forums/default.aspx?f=33&m=262907

Questions about how long it takes to start a cog and other ways of accomplishing things. http://forums.parallax.com/forums/default.aspx?f=25&m=263541&g=263593

Sine wave output from the prop http://forums.parallax.com/forums/default.aspx?f=25&m=261056&g=261067

Pre-fetch and self modifying code. Something to watch out for! http://forums.parallax.com/forums/default.aspx?f=25&m=260965

Some questions and answers on accessing bytes in larger variables. http://forums.parallax.com/forums/default.aspx?f=25&m=262787

Some general questions and answers about what the prop can do. http://forums.parallax.com/forums/default.aspx?f=25&m=264271

Getting data from one pin to another and a how to use the timers to do it. http://forums.parallax.com/forums/default.aspx?f=25&m=264649

Changing variables between long and byte. http://forums.parallax.com/forums/default.aspx?f=25&m=265586

Basics and Beyond

A question about required crystal accuracy. http://forums.parallax.com/forums/default.aspx?f=25&m=261089&g=261115

and more questions about crystals http://forums.parallax.com/forums/default.aspx?f=25&m=259385&g=264662 http://forums.parallax.com/forums/default.aspx?f=25&m=264577&g=264843

What are the threshold voltages of the prop? This tells you for one prop. http://forums.parallax.com/forums/default.aspx?f=25&m=260930&g=261152

Questions and answers about what can hang a cog http://forums.parallax.com/forums/default.aspx?f=25&m=260908&g=261255

Another fried PLL and some hints from Paul about how prevent it happening. http://forums.parallax.com/forums/default.aspx?f=25&m=261542&g=262166

Pops and clicks in audio and how to avoid them. http://forums.parallax.com/forums/default.aspx?f=25&m=261767

Tools and methods for fixing memory corruption problems. http://forums.parallax.com/forums/default.aspx?f=25&m=253901

Using the pos/neg edge detector timer modes. http://forums.parallax.com/forums/default.aspx?f=25&m=262573

Initial states for the c and z flags. http://forums.parallax.com/forums/default.aspx?f=25&m=262837&g=263003

QTI sensor code is here. http://forums.parallax.com/forums/default.aspx?f=25&m=263689&g=263689

What does the @ operator do in asm? Also a tip on the @@ operator. http://forums.parallax.com/forums/default.aspx?f=25&m=264399

Questions about graphics and VGA (again, hopefully some answers this time). http://forums.parallax.com/forums/default.aspx?f=25&m=264361&p=1

More discussion about high speed comms. http://forums.parallax.com/forums/default.aspx?f=25&m=264379&g=264477

Problems with the CORDIC object. http://forums.parallax.com/forums/default.aspx?f=25&m=264018

Questions about SPIN speed and the interpreter. http://forums.parallax.com/forums/default.aspx?f=25&m=266040&g=266043#m266043

Advanced

Creative use of the object[x].method notation to solve some problems http://forums.parallax.com/forums/default.aspx?f=25&p=1&m=260504

Questions about queues and some examples http://forums.parallax.com/forums/default.aspx?f=25&m=262504

Discussions on loading new LMM cogs in ImageCraft C http://forums.parallax.com/forums/default.aspx?f=25&m=263048&g=263456

Discussions about new features for the spin compiler. http://forums.parallax.com/forums/default.aspx?f=25&m=260170&g=261362

Using the prop as an RF transmitter and receiver. http://forums.parallax.com/forums/default.aspx?f=25&m=261275

New Programs and Objects

An I2C Slave driver is now available in spin and assembly thanks to hippy (who has a D'Oh moment while testing multiple slaves). http://forums.parallax.com/forums/default.aspx?f=25&m=263375&g=263520

Distance and Bearings calculations object for the prop by Chuck. http://forums.parallax.com/forums/default.aspx?f=25&m=263181&g=263266#m263266

Ymodem upload utility by Rayman. Upload files from your propeller to your PC! http://forums.parallax.com/forums/default.aspx?f=25&m=261220

High speed serial by Stephen. http://forums.parallax.com/forums/default.aspx?f=25&m=262414&g=263008

Quad DRO by Richard. Useful if you have a mill/lathe or anything else you need measurement info for. http://forums.parallax.com/forums/default.aspx?f=25&m=262412&g=263235

A pop3 email client for the prop that displays the message From: and Subject: fields on your TV. http://obex.parallax.com/objects/259/

On prop development using a spin like syntax. Again thanks to hippy. http://forums.parallax.com/forums/default.aspx?f=25&m=264289&g=264403

Steven finally finishes the XOR version of Graphics.spin including the ROM font. http://forums.parallax.com/forums/default.aspx?f=25&m=248864&g=264881#m264881

PropBASH, a modded version of PropDOS that is more like BASH http://forums.parallax.com/forums/default.aspx?f=25&m=265024

VGA Text driver for ImageCraft C. http://forums.parallax.com/forums/default.aspx?f=25&m=266216

Gotcha

Assembly, MUL details divulged. (w/commented code) http://forums.parallax.com/forums/default.aspx?f=25&m=261282

References

Basics

Prefetch impacts self-modifying code (w/link to deSilva asm tutorial) http://forums.parallax.com/forums/default.aspx?f=25&m=260965

Can a cog get stuck waiting? http://forums.parallax.com/forums/default.aspx?f=25&m=260908

byte basics http://forums.parallax.com/forums/default.aspx?f=25&m=262787

Basics and Beyond

Audio: pops at start and stop of wav file http://forums.parallax.com/forums/default.aspx?f=25&m=261767

Debugging programs, best practices (divide and conquer) http://forums.parallax.com/forums/default.aspx?f=25&m=253901

On negative edge counting (counter setups) http://forums.parallax.com/forums/default.aspx?f=25&m=262573

Advanced

On queues http://forums.parallax.com/forums/default.aspx?f=25&m=262504

GPS: conversions, ddmm.mmmm to dd.dddd, radians. (link to Circuit Cellar) http://forums.parallax.com/forums/default.aspx?f=25&m=262819

Parallax stuff

embedded props get a write up. http://forums.parallax.com/forums/default.aspx?f=25&m=261005

propplug logo up on protoboard http://forums.parallax.com/forums/default.aspx?f=25&m=262269

Hardware

on radio control, http://forums.parallax.com/forums/default.aspx?f=25&m=262102

signals between 3.6v and 5v chips http://forums.parallax.com/forums/default.aspx?f=25&m=262865

Counters

FSK, signal synthesis, decoding discussion. http://forums.parallax.com/forums/default.aspx?f=25&m=261275

Demos

Ymodem: upload data as [binary] file http://forums.parallax.com/forums/default.aspx?f=25&m=261220

Circuitry

circuit design precautions and guidelines (how2 stop frying pll's) http://forums.parallax.com/forums/default.aspx?f=25&m=261542&p=1

use a 1K pull-up on prop plug whose cable will removed http://forums.parallax.com/forums/default.aspx?f=25&m=261253 more info inc fish's schematic: http://forums.parallax.com/forums/default.aspx?f=25&m=192068

on pull-up resistors http://forums.parallax.com/forums/default.aspx?f=25&m=261993

Adverts

Imagecraft C 20% discount http://forums.parallax.com/forums/default.aspx?f=25&m=261910