Memory expansion

Chen

Anyone with any experience on the expansion of program memory of Basic Stamp? The space is limited. And, if there is someone who once did program expansion with Microchip PIC microcontrollers? Or any web link to introduction of such material as big memory programming? Do I have to use microprocessors for expansion?

Your opinions count.

Mike Green

You cannot expand program memory of the Basic Stamp. There is no way to do it. You can replace one model of the Basic Stamp with another that already comes with multiple 2K “pages” of program memory (like the BS2p series), but the additional “pages” are limited in how they can be used. The Reference Manual and a couple of Nuts and Volts columns describe the statements that can be used.

erco

Old school, if you can find one, there's the Parallax StampMem...

https://forums.parallax.com/discussion/download/114447/StampMem_Manual_v1_1.pdf

mikeologist

erco wrote: »

Old school, if you can find one, there's the Parallax StampMem...

https://forums.parallax.com/discussion/download/114447/StampMem_Manual_v1_1.pdf

That's cool.
I read the manual and now I'm curious as to why you can use the 27939 with a stamp but you can't use an external serial flash? Is the stamp too slow?

Mike Green

You can use external serial flash with a Basic Stamp, but only for data storage, not for program storage, and (!!!) it doesn't extend any of the built-in variable storage mechanisms. There's a Nuts and Volts column on interfacing with I2C devices that shows how to do this. The code required to access an I2C device takes a lot of space in the limited Stamp program memory, but it does work. The BS2p series Stamps have built-in I2C statements that make this much easier and less costly in terms of program memory. Again, you can't extend any of the built-in memory of any of the Basic Stamp models ... whether for program or data, but you can use external serial flash for data storage separate from (and much less useful than) the built-in variable memory.

The StampMem that erco mentions is a peripheral device with its own controller. It listens for and interprets serial commands that allow it to use memory attached to the controller (probably a PIC of some sort).

Tracy Allen

The original Stamp 2 has a much easier time with SPI external memory, using its built in SHIFTIN and SHIFTOUT commands. Example, the CAT25512 give you 64kbytes of external memory that can be used for things like data logging or storing patterns or text. (not programs).

As Mike pointed out, the 'p series Stamps have extended memory. For example, my favorite, the BS2pe, comes with 16 banks of 2048 bytes, and 8 of those can store program code, and you can chain code from one bank to another. The other 8 banks are for data storage only.

mikeologist

Mike Green wrote: »

You can use external serial flash with a Basic Stamp, but only for data storage, not for program storage, and (!!!) it doesn't extend any of the built-in variable storage mechanisms. There's a Nuts and Volts column on interfacing with I2C devices that shows how to do this. The code required to access an I2C device takes a lot of space in the limited Stamp program memory, but it does work. The BS2p series Stamps have built-in I2C statements that make this much easier and less costly in terms of program memory. Again, you can't extend any of the built-in memory of any of the Basic Stamp models ... whether for program or data, but you can use external serial flash for data storage separate from (and much less useful than) the built-in variable memory.

The StampMem that erco mentions is a peripheral device with its own controller. It listens for and interprets serial commands that allow it to use memory attached to the controller (probably a PIC of some sort).

Cool, thanks for clearing that up.