I have fitted a larger character backlit LCD screen to my Optimiser running on a remote lead clipped to the edge of my windscreen. It has an LED backlight, my problem is I cannot identify the pins 15 and 16 on the Optimiser PCB for the backlight power. Supplying 5v to the corresponding pins on the LCD make it light up nicely though. The LCD displays the normal Optimiser dialog OK.

I am not sure if I can safely connect the LCD backlight direct to the power input to the Optimiser or if I should add R1,R2,T1 and then wire it to the Optimiser pcb holes 15,16, in which case I need to be able to identify them.

This is the larger LCD, not sure if it is an adequate link.

http://www.ebay.com/itm/Larger-Character-LCD-Module-Display-LCM-1602-16X2-162-/200503698836?pt=LH_DefaultDomain_0&hash=item2eaef3a594

Thanks. :o

The 2 connections for the back light are just above the RJ45 connector. The one closest the PCB edge is the +5V feed. The other goes via the 10ohm resistor to the BC547 transistor.

There is some logic in the Optimiser to only activate the back light when the ECU voltage and engine RPM satisfy  so you may only see it if the engine is running, If you want to change this you can take the 47K resistor and pull out the leg that goes to the chip and switch it to 5V the way you want ( another switch or permanent )

Keep in mind that the back light takes about 100mA and this will reduce the ECU voltage booster's output. So keep an eye out for  for the ECU/Optimiser resetting while cranking.

Hi Cliff, I am a bit confused by the reference to the RJ45 connector as there isnt one on the Optimiser.

I understand your concern about the backlight robbing power during cranking, very clever of you to design it so it only provides power to it once the motor is running and voltage had risen.  So if I decide to wire it direct to +5v best to have a switch to control it.

I really like the Optimiser - the only problem for me was the small display and the need to find streetlamps to see what was happening.

The RJ45 connector is at the lower right of the PCB ( where the cable plugs in ). It slightly different to the one on the ECU side but I believe it is still called and RJ45

With wiring your own just make sure the 5V you switch goes via a resistor to the bse of the transistor

Ah, I now remember I had problems some time ago with the socket and removed it, my cable to the MyEcu is now hard wired to the Optimiser pcb. Thanks for the help.

Having got the larger display working OK I now wish to mount the Optimiser in a different case. 

Can I assume the second potentiometer is now unlikely to be used, as developement seems to be moving over to the Android MyEcuController.

Can I just remove the second pot and cut the wires back?


As an aside, when I wired up the larger LCD it worked fine, then I noticed your assembly notes about reversing pins 1&2 which of course I had not done, does this reversal only apply to the LCD you originally supplied?

Yes I think its safe to ignore the 2nd pot as I'm not planning on developing the Optimiser any more. I've already removed it from the main web site.
Just leave the wires as unconnected.

The reversal for pins 1 & 2 was probably just for that particular LCD. They're actually the 0 and 5V lines so the fact it works means you got it right.