Hello,
I'm trying to make a system that will allow me to set a value say float volume and have it keeping the same last set value after power down and boot up without using EEPROM since it's not that important and it could happen continuously wearing out the EEPROM fast.
Is it possible to do that?How?
Really? How often does your volume change? What do you mean, "it's not that important"?
What have you tried?
aarg:
Really? How often does your volume change? What do you mean, "it's not that important"?
A user can change that "variable" a few times a second and the system is expected to be shut down unexpectedly and needs to remember certain values that were set in the last session.
Whandall:
What have you tried?
Nothing just initializing the variable with nothing I guess you'd have to set it in some constant pre known adders.
So "I'm trying to make a system" translates to "I have no clue how to fulfill my strange wishes" nowadays?
Use the EEPROM, save the value not too often, if you manage to kill some cells, switch to different ones.
Have a look at AVR101: High Endurance EEPROM Storage
Arduino EEPROM is the only way to save such variable information during power off.
You can expect about 100,000 EEPROM write cycles (minimum), so plan your program accordingly.
Can't it read it off a particular address at the flash memory?
Flash wears out faster than EEPROM.
Then how do they do it smartphone and computers reliably if reliably?
Got a ds1307 rtc module? That has some battery backed ram. You could store the value there. Ram does not wear out (as long as the battery is ok).
MikeLemon:
Then how do they do it smartphone and computers reliably if reliably?
Wear-levelling algorithms
PaulRB:
Got a ds1307 rtc module? That has some battery backed ram. You could store the value there. Ram does not wear out (as long as the battery is ok).
Can't add hardware that much.
How about an 8-pin FRAM chip? Pretty small in a workable (hand assemblable) SOIC package,or smaller if you're talented. 10 to 100 trillion write cycles. No need for crystal and pullups, etc that DS1307 needs, or battery. SPI interface for fastest writes, same as writing to external SRAM (vs 3.3mS for internal EEPROM). Non-volatility of EEPROM without needing a battery.
These are 512x8, larger storage sizes are available in the same package too.
Check for 5V operation, some are 3.3V only.
Seconded on the FRAMs, I have used both the Cypress ones and Fujitsu SPI and I2C, they seem reliable so far.
The cypress ones have a particularly high endurance, if you could write to one around 1000 times a second, its still going to last around 3,000 years.
How much data do you need to store?
MikeLemon:
A user can change that "variable" a few times a second...
How? By what mechanism is a (presumably human) user able to change a value a few times a second?
A pot or knob encoder?
CrossRoads:
How about an 8-pin FRAM chip? Pretty small in a workable (hand assemblable) SOIC package,or smaller if you're talented. 10 to 100 trillion write cycles. No need for crystal and pullups, etc that DS1307 needs, or battery. SPI interface for fastest writes, same as writing to external SRAM (vs 3.3mS for internal EEPROM). Non-volatility of EEPROM without needing a battery.
These are 512x8, larger storage sizes are available in the same package too.
Check for 5V operation, some are 3.3V only.
https://www.digikey.com/products/en/integrated-circuits-ics/memory/774?k=fram+memory&k=&pkeyword=fram+memory&pv142=1636&nu800=kHz&xu800=kHz&pv2043=11&FV=ffe00306&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25
Well NVM thank you the element isn't that important that it deserves some hardware maybe I'll try the EEPROM method anyways and just not care about hard long term use.
jremington:
A pot or knob encoder?
That a human changes constantly for an eight hour shift? With three shifts a day?