Reply
Thread Tools
Posts: 1,104 | Thanked: 5,652 times | Joined on Feb 2010 @ Holland
#1
So, I found this in my mailbox today:



An AT24C02 EEPROM with a wopping 256 bytes of data

Since EEPROMS are very very easy to program, this is a very quick way to make your custom OH instantly very awesome!

But, since I am an extreme hardware guy (and a little low on software knowlegde), what to put on them??

Howto:
-download a picture and set it as ambiance?
-download and install a program?
-change settings?
-start a daemon?

Also, they are dirt-cheap.
 

The Following User Says Thank You to dirkvl For This Useful Post:
Posts: 1,104 | Thanked: 5,652 times | Joined on Feb 2010 @ Holland
#2
Also, GITHUB has this page

struct toh_eeprom_entry toh_eeprom[] = {
{ TOH_EEPROM_VENDOR, 2, 0 },
{ TOH_EEPROM_PRODUCT, 2, 2 },
{ TOH_EEPROM_REV, 1, 4 },
{ TOH_EEPROM_EEPROM_SIZE, 2, 5 },
{ TOH_EEPROM_CFG_ADDR, 2, 7 },
{ TOH_EEPROM_CFG_SIZE, 2, 9 },
{ TOH_EEPROM_UDATA_ADDR, 2, 11 },
{ TOH_EEPROM_UDATA_SIZE, 2, 13 },
};
 
Community Council | Posts: 4,920 | Thanked: 12,867 times | Joined on May 2012 @ Southerrn Finland
#3
Well, 256 bytes don't hold very impressive images or sounds. that's for sure

I'd imagine what you can put there is an URL that gets downloaded by the system when you insert the EEPROM, for example. Now you'd need to write up a daemon that gets kicked when an EEPROM of the signature you have gets inserted to I2C...

Last edited by juiceme; 2014-01-14 at 06:12. Reason: corrected typo
 

The Following User Says Thank You to juiceme For This Useful Post:
Posts: 646 | Thanked: 1,124 times | Joined on Jul 2010 @ Espoo, Finland
#4
Originally Posted by dirkvl View Post
An AT24C02 EEPROM with a wopping 256 bytes of data

Since EEPROMS are very very easy to program, this is a very quick way to make your custom OH instantly very awesome!
256 bytes is about same capacity of the NFC tags. If it's just to recognize the OH wouldn't be better to use those (and spare the energy to power the EEPROM) ?
Otherwise, how does read/write cycles in NFS tags and EEPROMs compare, when they are used to periodically store temporary data?
 
kimmoli's Avatar
Posts: 562 | Thanked: 2,744 times | Joined on Dec 2013 @ Espoo, Finland
#5
Remember that the VDD in toh is 3.3V, and I2C levels are 1.8V CMOS, so the EEPROM might not talk with you.
 
Posts: 1,104 | Thanked: 5,652 times | Joined on Feb 2010 @ Holland
#6
Originally Posted by juiceme View Post
Well, 256 bytes don't hold very impressive images or sounds. that's for sure
Well no, that's why I said 'download' image Although there are also a lot bigger EEPROMS, I think its power is in simple commands.

Originally Posted by minimos View Post
how does read/write cycles in NFS tags and EEPROMs compare, when they are used to periodically store temporary data?
Stand-by current of eeprom = 8 micro-amps. Read/write is a bit higher, but write time is a few milliseconds. The thing is, EEPROMs are available and Jolla NFCtags are not. Also, when you are making a PCB for an OH, it is way easier to also put an EEPROM on there instead of also making an NFC tag.

Originally Posted by kimmoli View Post
Remember that the VDD in toh is 3.3V, and I2C levels are 1.8V CMOS, so the EEPROM might not talk with you.
I believe EEPROMS are designed with flexibility in mind, so I think this will be okay!

Originally Posted by juiceme View Post
Now you'd need to write up a daemon that gets kicked when an EEPROM of the signature you have gets inserted to I2C...
Ha! See this post. Thats the beauty, the phone automatically looks for it.

Anyway, the question was not 'if' but 'how'! What kind of commands could you put on there?
 
kimmoli's Avatar
Posts: 562 | Thanked: 2,744 times | Joined on Dec 2013 @ Espoo, Finland
#7
Originally Posted by dirkvl View Post
I believe EEPROMS are designed with flexibility in mind, so I think this will be okay!
you wish... with I2C, anything is possible, it is "standard", but implementations varies.

VinHIlow = VCCx0.7V (aka CMOS) and when VCC is 3.3V, means that SDA/SCL needs to be ~2.3V to make sure them to be high.
(Ref AT24C02 datasheet)
 
Posts: 1,104 | Thanked: 5,652 times | Joined on Feb 2010 @ Holland
#8
Okay, then i put an regulator in between that outputs 2 volt to the Vcc of the EEPROM, problem solved. At least for trial fase.
 
Posts: 1,104 | Thanked: 5,652 times | Joined on Feb 2010 @ Holland
#9
In recent developments, the qwerty-oh is upgraded with a 1.8V voltage regulator, which mean I will very probably also stick an EEPROM on there.

Has anyone -by chance- come by some EEPROM commands for Sailfish?
 
Guest | Posts: n/a | Thanked: 0 times | Joined on
#10
Originally Posted by dirkvl View Post
In recent developments, the qwerty-oh is upgraded with a 1.8V voltage regulator, which mean I will very probably also stick an EEPROM on there.

Has anyone -by chance- come by some EEPROM commands for Sailfish?
you'll need to create that interface yourself
An eeprom is programmed by electric signals on designated addressbusses and will output whatever you put in their. Those instructions can then be used by microcontrollers, or TOH, interpreting the output.

http://www.engineersgarage.com/elect...s/24c02-eeprom
 
Reply

Tags
eeprom, otherhalf

Thread Tools

 
Forum Jump


All times are GMT. The time now is 15:50.