Data Logger Using PIC & 24LC16B (EEPROM)

[nicko-391]

Im going to make a Digital-Multimeter with a data Logger.External EEPROM is used
to store data.

Multi-meter has five digits.How can I manage EEPROM which has 2K memory to store measured values with Unit. Please give me & Idea.

 

[horace1]

any idea what range of measured values you are going to store and how many different units ?
The most space efficent way to store data is in binary rather than as character strings.
for example you could always store voltages in mVolts using a 24 bit number (3 bytes in EEPROM) giving a range of approx -8388.608 to + 8388.608 volts. If you don't need such a range so you could use some of the bits to indicate the units Mvolts, mAmps, ohms, etc.
it you need a larger range you could use 32 bit numbers etc.

 

[andre_luis]

5 digits means 10^5 magnitude ( 99.999 ) and with only 3 bytes ( 2^24 ) you can manage that storage.
Even wasting 1 byte ( 3+1 ) to make easyer the pointer access you can achieve ~250 records ( 2K/4 ).

+++

 

[horace1]

have a look at Microchip's Temperature Data Logger Demo Board it may give you some ideas
**broken link removed**

 

[nicko-391]

There are 17 units, except AC/DC. Maximum Value is 19,999.

 

[horace1]

you could use three bytes for each value
1 byte holding the units
2 bytes holding a signed 16 bit integer range -32768 to 32767

 

[klystron]

Take a look at this low power temperature logger that stores transactions in code memory https://www.compendiumarcana.com/datalog/