Reading EEPROM from PC

Adriano72

Hi all,

I would like to read the Eeprom data of a BS2 without using the Basic Stamp Editor. For example, imagine that I build a temperature measurer that register checks done all day long and then I want to plug this device to the pc via USB and get the data so I can build reports etc...

How can I accomplish this task?

Thanks to all

Cheers

Adriano

Mike Green

There is no practical way to directly access the EEPROM data from a PC. The normal way this is done is to have a jumper on your Stamp board that can be read from an I/O pin. In the initialization portion of your logging program, you have a test for the jumper setting and that goes to a portion of your program that communicates with the PC using DEBUG / DEBUGIN statements.

The StampPlotPro program (which is available from Parallax for free non-commercial use) is intended for just this sort of use and can save PC files or plot / print downloaded data. Look at the documentation for it: www.parallax.com/tabid/441/Default.aspx

Adriano72

Thanks Mike,

but I have not understood what do you mean about the jumper. Is not a jumper that tiny plastic removable switch? Like that one that switches between Vin and Vdd?
And how can I read the jumper from the I/O pin?
Forgive me but I'm very very newby.

Thank you

Adriano

Tracy Allen

Adriano,


Near the top of your program, have a statement similar to this:

top:
  DEBUG "Press D to download data"
  SERIN 16,$54,2000,main,[noparse][[/noparse]char]
  IF char="D" THEN download   ' this happens only if user presses "D"
  ' also can have other commands, e.g. erase, set clock etc.
main:
  DO
    ' collect data in locations 
  LOOP

download:
  FOR index=0 TO endofdata STEP 2  ' read words
    READ index, Word result
    DEBUG SDEC result, CR   ' signed decimal results
  NEXT
  GOTO top

Capture the data download in a program such as Hyperterminal. You also need means to erase the old data and to start over. There are several ways to do that, depending.

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Tracy Allen
www.emesystems.com

Mike Green

If a PC is connected to the Stamp, Tracy's suggestion displays a message, then waits 2 seconds for a character to be received. If nothing is received in 2 seconds, the program continues on as it would have before (at main). If a "D" is received, it dumps data to the PC where a program like HyperTerminal can store it in a file.

My suggestion was to do pretty much the same thing, but to use the setting of a jumper instead of typing a "D" on the PC.

A jumper is just a wire that connects two points on a circuit board. These days, it's usually a set of pins sticking up from a printed circuit board, commonly on a 0.1" grid. There are molded connector blocks that can be installed over a pair of pins that connect them together. In this case, one pin would be connected to a Stamp I/O pin with a 10K resistor connected between the I/O pin and Vdd. This provides a default voltage of +Vdd on the I/O pin. The other jumper pin is just connected to ground (Vss). If the connector block is absent, the I/O pin reads high (1). If the connector block is installed, the I/O pin reads low (0). There are examples in the Stamp Basic Syntax and Reference Manual of reading the state of an I/O pin. If you're using I/O pin 11, you'd use the value of IN11 in your program.

Adriano72

Thank you very much Mike and Tracy!

I'll do some tests and quite sure I'll be back with more questions...

A great hug!

cheers

Adriano