LCD and cold temperature

[Magister]

what a messy display

I have the regular blue one from NKC, it's rated 0 to 50°C (32F to 122F) but we have something like -49F (with wind, it's just -28F without wind) the night here...

The morning when I start the car (I have a block heater, no problem here, coolant temperature was 55F this morning for instance), the LCD which should be white on blue is more like black on blue and the refresh rate is in seconds, so I got messy black pixels for a couple of minute until the LCD is warmer

BTW each time I start my OBDuino in the -20F or less, there is no problem, atmega168 and others have no problem running.

I am remaking an OBDuino on a small board (3"x2") and I guess I will search for an LCD with extended range

[dcb]

I chose this one for it's temperature performance (after a tip from paulb to watch out for temperature performance), but mouser has the same temp specifications for most of them now:

NHD-0216K1Z-FL-YBW

[Magister]

This morning at -28°F my LCD became an SCD, a solid crystal display
It took quite a time for it to "melt", I hate this winter

[dcb]

FYI, it was -5 here and I had to make sure the car would start (left it out).

The LCD was responding, but very slowly. Painting a pixel black was instantaneous but it took about 6 seconds for the pixels that were not supposed to be black anymore to clear up enough to read well. So the trips should be useable, but the instantaneous readings were a blur.

[wyatt]

I have the same blue NKC display. It was +5F (-15C) this morning and I had no problems with refresh rates or it turning into a SCD. Since this is about as cold as it gets for this part of Alabama, I should be ok until I have to go somewhere colder. If mine is rated for 0C and it is good at least to -15C, I wonder how good dcb's is that's rated to -20C...

[wagonman76]

Great thread, I logged in planning on starting this thread.

Mine is like dcb said on most winter mornings, everything works but it updates slow and is a bit of a blur.

This morning was obviously the coldest all winter. A coworker said it was -14F about 25 miles inland from me. Judging by the way the car cranks at various temperatures, I think it was more like -20F at my house. The bottom row of characters was fine, but the top row only contained the bottom row of pixels, so it was like a row of underscores. It took about 5 miles to get some heat in the car and get the display to come back. But I have not had one single glitch with the operating system, it is still working 100%.

[dcb]

Theres this: M0216SD-162SDAR2-1 it lists a- 40 C to + 85 C range. But would need a couple code tweaks.

I tried cranking up the contrast to about 110 and that seemed to help, still sluggish but at least I got a ghosty image of a number on the changing numbers instead of a muddle of black.

[dcb]

-10 this morning, much less responsive than at -5, looked at a scangauge too, it was even more sluggish. My cell phone never displayed anything (it does once it warms up).

Is anyone willing to pay an extra $30 for the vfd hardware for better temperature response with their mpguino?

[Magister]

The VFD is too expensive I guess.

An LCD doing -20°C to +70°C should be ok for almost everyone.

This morning was the coldest in 12 years, -31°F, the EL lit but there was no display for a couple of minutes, but no problem with the atmega or communicating with the MCP2515 and the ECM

[wyatt]

Originally Posted by dcb

Is anyone willing to pay an extra $30 for the vfd hardware for better temperature response with their mpguino?

If you get 50 it's only an extra $20... Would be cool, but to me it isn't enough of a problem to pay the extra.
One alternative would be to use the female headers to connect the LCD to the MPGuino. That way people can disconnect the LCD at night and take it inside where it's warm. I don't know if there are problems with connecting and disconnecting headers lots of times, but it is an option. If I'm not careful, it's going to wind up sounding like I have an interest in how the female header companies do... this is like the 5th time I have suggested it...