Need for speed

[melazarus]

Hi all,
I'm new on this forum and have been playing with the Picaxe chips for quite a while now and I realy love them.

But I have a problem with a project I'm dooing at the moment.
I like to serial (serin) control 110 LED's with a 08M chip. I found that the 74595 is ideal for this project.
but as you can imagine, this is slow. I takes litle less than one second to update all led's (w/o the serin time).
This is mainly becouse the picaxe language is interpreted by the chip I understand.

I read that there is an possibility to convert the picaxe basic language to asembler and then burn the hex file to a PIC chip.

My question is now, will this make my programm any faster?
Or will it still be interpreted by the chip?

Has anyone any experience with this?

Thanks alot for anyone who takes the time to read/answer this.

BTW: The goal of the project is to control 55 duo LED's (=110) that are build in a map. The chip will listen for serial data comming from the PC and display it.

 

[hippy]

Converting to Assembler and burning a PICmicro will definitely improve execution speed ( and it will run 'native' and not be interpreted ), but the Rev-Ed supplied converter is an educational tool so does not support all PICAXE commands. You may have to manually re-code parts of your program directly in Assembly Language, and you will have to find or write routines to do those tasks which the converter doesn't support; Serial Input for one.

There are alternative commercial compilers which will convert Basic direct to Assembler or burnable file, but you may need to re-code your program to compile and you may have to purchase a compiler if your program is too complex for a demo version.

An alternative is re-coding in a different high-level language, but you have to choose one and may still need to find libraries or write your own code to replicate what each PICAXE command does and will have to find and learn how to use the software tools.

A forum search should reveal further discussion on conversion to PICmicro.

You are using a PICAXE-08M but it might be worth considering a PICAXE-18A or 18X and looking at the work I did on high-speed SPI output. The 18A should support SPI out.

This should certainly improve the speed at which data bytes can be output from a PICAXE to a shift register such as the 74595.

That's what I'd consider and recommend doing first, as you can then stay with the PICAXE and won't have to purchase any additional software tools or programmers nor have to go to other forums to seek advice on problems which arise.

Edited by - hippy on 19/01/2007 14:30:44

 

[melazarus]

Thanks for the info. I don't mind learning an other language if it works a the end. But I'll take a look at the high speed SPI stuff you wrote for the 18X. It looks prommising as it will allow me to keep the serin command.

thanks

 

[kranenborg]

Hello,

You might consider a 28X running at 16Mhz together with a MAX6955 LED driver, using the i2cfast16 keyword for proper i2c speed. This driver supports a maximum of 128 leds (individually controllable), and I have found it to be extremely versatile (albeit somehat complex too due to the plethora of options).

Regards,
Jurjen
http://www.kranenborg.org/ee/picaxe

 

[Jeremy Leach]

You're talking a lot of serial in, parallel out with the 74595 chips then? So you're trying to bit-bang the serial feed to the chips from PICAXE code?

If so, then I think some of Hippy's recent discoveries regarding high speed comms might help you. Hippy ...can you give any tips?