Data logging from microcontroller

[justin_t]

Hi
I have a project where a Microcontroller (Atmel mega162) controls the switching on/off times of a motor/heater.
I would now like to make a data logger that will store the date and time of day that the switching occurs.
I would also like to be able to extract the data from the control board with out having to connect it to my PC.
I imagine i can do all the data logging in my microcontroller by storing each event to 4x8bit EEPROM addresses at as the time of day and day are supplied to the controller via a RTC chip.

The problem now is how do i get it from the board?
Ive looked into finding a USB driver that will change the seriel EEPROM data into something a USB pen drive can receive but with out a master controller this doesnt seem to be a suitable option.

I was then thinking about looking for some sort of bluetooth chip that might transfer the data to a mobile phone.

Does either of these options sound like they might work or has any one come across a similar problem?

justin_t

 

[3v0]

Is there a reason you can not use a memory card like a camera uses. SD seems to be popular. Sparkfun has a breakout board.

 

[justin_t]

Yeah, i havent thought of that, maybe mount a little SD holder on the board and send information to it. ill prob need another driver chip between the 2 but that sound like an excelent idea. ill look into it

 

[3v0]

Yeah, i havent thought of that, maybe mount a little SD holder on the board and send information to it. ill prob need another driver chip between the 2 but that sound like an excelent idea. ill look into it

Why use the EEPROM at all? Log the data to the SD card. Erase or empty the data file on the PC when you read it. If you use 2 cards you can insert an empty one and take the one with the data with you to be downloaded.

Be sure to have the code check if the SD card is present and hold an event or two in temp storage in case you pull the card just prior to an event.

 

[justin_t]

i havent looked that maxim example yet but im guessing ill need software that will be able to read the code and display something to the layman that he can understand.

 

[3v0]

i havent looked that maxim example yet but im guessing ill need software that will be able to read the code and display something to the layman that he can understand.

I could be more helpful if you were using a PIC. But I do not think the interface to the clock chip should be a problem. There is a good chance you can find the code already written or at least code you can leverage.

The SD card is where I would start. But as with most AVR request you would be better off over at AVR Freaks.

 

[justin_t]

ha! yeah youre prob right but thanks any way.
im away for the weekend but ill let you know how things go