RV1 10k trimmer- what's it for?

[tom_tm]

Hi Xavier.

Finally got around to building mine. I used the Mouser BOM, but got a trimmer, which looks like it's supposed to be RV1. What's it for, as it doesn't suggest anywhere about fitting it.

Also what are connectors P1 and P3 for?

Lastly, those looking for the PCB header pin arrays used for the OLED, in the UK, Maplin sell these which is handy to know- since I couldn't find them at either Mouser UK or RS.

Cheers!

Tom

[Xavier]

Hi Tom,

RV1 is the contrast resistor for LCD display. Useless if you have a OLED display.

P1 and P3 are describe at the end of this FAQ  :
http://ixox.fr/forum/index.php?topic=63377.0

Thanks for the Maplin tip. Ebay is also good place to buy low profile pins header if you're patient :
Search for "Single Row Round Pin 2.54mm Pitch Spacing Header"
They're cheap if you buy many.

Xavier

[tom_tm]

Fantastic stuff Xavier!

One more question, the brightness seems a little dim on the OLED. Is there anyway of increasing it?

Tom

[tom_tm]

Ah. This is odd. When I turn rotary 1 to change algorithm although these change, the screen brightness also changes! Is this a feature?

[tom_tm]

It gets even stranger. Turning the other rotaries, compromises the brightness completely! Something can't be right. I haven't updated the firmware yet (if there is an update?). Still on 2.0.6

[Xavier]

What PCB revision do you have ?
If R5d, check the OLED resistor is not empty.

Last firmware is 2.0.7 but that won't fix your problem :
http://ixox.fr/forum/index.php?topic=63505.0

[tom_tm]

Hi Xavier.

Board revision is R5d

The OLED resistor isn't in place. ('OLED=0 or 22 for Mod'... etc?). Should I solder in a 22Ω resistor?

EDIT: "If you have a PCB R5d (or +) : solder a 22ohm at the "oled" position and go to step 4 directly... DON't do step 1,2,3."

Ahh! Just reread this. Will try now.

[tom_tm]

Eureka!

All working fine! 8-)