add on memory

[rigidigital]

i want to continue using the 08M or 14M can I add on memory ram and or eeprom ? to these chips ?

 

[Andrew Cowan]

What do you want the memory for?

Storing variables (volitile)?
Storing variables (non volitile?)
Having a longer program?

Andrew

 

[rigidigital]

thanks

for storing variables/ inputs from a keypad then eventually sent via uhf or digital.

 

[Andrew Cowan]

The main method for expanding memory is I2C, and this is only compatible with X parts. (18X, 28X etc).

Andrew

 

[hippy]

You can add bit-banged I2C Eeprom / Ram but that eats into available code space and can only be used for data storage.

You cannot magically create extra variables although you can use the PICAXE internal Ram (SFR) and move data between Ram and variables. You can also use this Ram for storing input for later use. See the PEEK and POKE commands.

 

[rigidigital]

Thanks for the solutions

I thought it was going to be tooo hard so I bought a Basic Stap starter kit cost hundreds.
Basic Stamps are around $80 aus dollars ! Considering I need about 25 of them I am going to head back to picaxe and figure out ic2 etc.

Are there any other microprocessors besides picaxe that can be programmed in basic ? Just a thought ?

Thanks again for your replies.

Mick.

 

[hippy]

Yes, there are other micros which can be programmed using Basic but the PICAXE is probably the easiest and often cheapest you can find.

An explanation of what you're trying to do will help people offer best advice. You may want to stick with the 08M/14M because of lowest cost, but if you have to start adding I2C you may be better off using an 18X and no I2C. Use an even bigger PICAXE and you might not need 25. There may also be other tricks which can help you get the most out of what you want to do.

 

[manuka]

RigiD. Check the table below for memory features of the entire PICAXE range. You may even benefit by waiting for the "anytime now" X2 offerings?

This is almost a brain teaser of course, but just what do you need 25 PICAXEs for?

 

[moxhamj]

There may well be other solutions to 25 picaxes. What are they doing? There could be TTL or other logic solutions with picaxes acting as controllers. There is the much higher memory of the bigger parts. For datalogging there are the eeproms. There are the new X2 parts. So many questions and it depends on what you are trying to do.

I'm currently working on a hybrid Z80/picaxe system with 1Mb of ram and a speed about 2,000x faster than picaxe and programmed in basic with lots of extra commands like text strings and floating point maths. But it is still in the early stages so don't build your project around it!

 

[rigidigital]

I will let u know what its all for

Just need to go home to my pc and check stuff and write a simple but hopefully clear plan, then ill be back.
thanks alll...

 

[rigidigital]

brainn teaser

RigiD. Check the table below for memory features of the entire PICAXE range. You may even benefit by waiting for the "anytime now" X2 offerings?

This is almost a brain teaser of course, but just what do you need 25 PICAXEs for?

Because I have 25 picaxes 25 key pads 25 tranceivers well thats the plan.

 

[BCJKiwi]

So are these one interconnected system, or 25 completely separate systems?
How much memory do you need?
How often does it change?

 

[moxhamj]

We are still a bit in the dark here, but these teasers are most intriguing. I do hope you haven't gone out and bought 25 picaxes and then found the code doesn't fit?

What do each of these devices do?

 

[manuka]

Ah-it's generally considered that proof of concept should be the first step in any technical venture. No one should normally order bulk supplies without establishing the "plane will fly" (etc) on a prototype! It reminds me of folks who rush into PCB making without first taming their circuitry.

Although PICAXE "transceiver" linking is well established, both Dr_A & I will verify fish hooks abound relating to data rates, power, frequency, range & interference. REGULATIONS also can be a spoiler. Ex. Although there is no voice restriction, the 40 channel 470MHz UHF CB band in Aus/NZ rigidly allows just 3 seconds an hour of data use on only 2 channels. Endless lobying has gone into changing this, but to no effect (so far)...

 

[moxhamj]

Indeed Manuka. Agree 100%. Though there are ways around this 3 second rule - eg by using large numbers of nodes that are self organising and use RF power under the limit ie 100 metres or less. This way, messages can hop between nodes and eventually will get there. Not so good for fast links, but perfectly adequate for sensing tank levels and stock troughs and wind turbine data and the like. I am actively working on a board for this - have just got an analog to analog link working. Eg 0-5V in =0-5V out but the signal can have bounced between any number up to 100 digital nodes to get there. The user does not need to know about that - just input a voltage and it comes out the other end. Ditto switches to relays. "Hope" modules are part of the solution. Will publish once it is working, but suffice to say the problem is not as simple as it first seems!