Control Bare LCD With ATmega328p

Status
Not open for further replies.

Athosworld

Member
I want to control a bare dot matrix display with an ATMega328p but I have no experience on doing this, what code do I need to create a “wiggle” AC signal to drive that LCD? Or do I have a driver IC between the ATMega and the LCD?
 
Sort by date Sort by votes
Its not R/W cycles. The chips had a few cycles during initial development then after everything was working the circuit was put away. Bringing them out years later show several not working and needing reprogramming. Part of it might be that I live in the tropics and that room is not air conditioned every day.

One trick that I did not consider until now is over-programming the flash, something I used to do with EPROMs -program them more than once with the same code and no erasures in-between to make sure the floating gates were fully charged or not. However waiting several years between tests makes for a very long test. Don't know how many years I have left ;-)

It might be that the early AVR chips were not as robust as the current chips. I think that flash memory in general improved a lot in the first decade of this century as have the processes.
 
Upvote 0 Downvote
Were the very old AVR's actually FLASH anyway?, they were (as far as I know) the first to label them as 'FLASH', but it was always suggested that they were still EEPROM like everyone else, who then followed suit and relabelled their EEPROM devices as FLASH (as it was the new 'buzz word' of the time).

But looking at the chart danadak posted, 20 years is probably the design life, at reasonable temperatures.
 
Upvote 0 Downvote
When I see that 20 year spec. in datasheets, I can only imagine that they verified it by accelerated aging or some other kind of simulation because it is still too early to have completed real-time life tests

The earliest AVR that I can remember was the AT90S1200 in which the Flash and EEPROM had very different endurance claims.

I remember being surprised in the late 2000's (2006 or later) when I recall I first saw mention of data retention in the spec sheets - this was probably an ATMEGA controller. Maybe they were reluctant to talk about retention until it was better.
 
Upvote 0 Downvote
Dick Cappels said:
When I see that 20 year spec. in datasheets, I can only imagine that they verified it by accelerated aging or some other kind of simulation because it is still too early to have completed real-time life tests
Click to expand...

Exactly, I've been trying to do accelerated tests on battery life - in practice we're looking (or hoping ) for 5+ years while transmitting data once a week. By setting a couple to transmit once a day instead, it 'roughly' should run out of battery in 1/7th of the time.

Dick Cappels said:
The earliest AVR that I can remember was the AT90S1200 in which the Flash and EEPROM had very different endurance claims.
Click to expand...

That's the data EEPROM, not the same thing as program EEPROM/FLASH - the data EEPROM has much lower read/write capability than program memory. Even the devices that admitted to using EEPROM program memory had vastly lower read/write capability for the data EEPROM.
 
Upvote 0 Downvote
According to the AT90S1200 datasheet there program is stored in flash and the EEPROM is accessible for data storage. Whether the "Flash" program memory was really Flash or EEPROM may be indicated by the endurance figures, which are very different (100:1 in favor of EEPROM).
 
Upvote 0 Downvote
Thats what I saw in Freescale, Cypress, etcc. EEPROM ~ 10 x FLASH limits in R/W cycles.


Regards, Dana.
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

F
  • Question
Issue with Interfacing LCD with PIC16F877A
2
Replies
22
Views
7K
Farhaad
F
P
Which MCU for translating usb-midi to control LED lighting?
2
Replies
28
Views
7K
be80be
S
  • Question
LCD 4Bit - PCF8574
Replies
10
Views
3K
Ian Rogers
  • Question
MAX7219: 7-segment and 8-digit display control (Oshonsoft).
Replies
0
Views
218
DogFlu66
J
  • Question
Controlling a Stepper Motor with Arduino
Replies
3
Views
2K
atferrari
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…