BOM for Ambika MOBO

Added a BOM for the MOBO to the wiki for Mouser. Everything directly from the BOM on the site EXCEPT I also added switch caps and arduino 6 pin headers ( a bit pricey there on the headers but saves ordering from more than one place). BOM here as well. Shouldn’t be errors, but would love for someone to look it over.

I’d highly suggest the Optrex C-51850 LCD. It’s absolutely amazing. It’s around $40 but worth every penny.

@qp do you eany the transmisive or transflective type? Transmissive is black letters on color background and transflective is white letters on black baclground right??
Is it better or as good as an OLED?

Mines Green letters on Black Background. The viewing angle is not as wide as OLED and there is still LED light leak in the black, but, the characters respond waaay faster than regular LCD Displays and are way brighter/crisper. Just got to remember to put a 100ohm resistor in or the LED will pop (as pichenettes did his first go with the LCD)

ordered… i went for white background with black letters… notetomyselfon/ ! HAVE TO REMEMBER 100 ohm resistor ! /notetomyselfoff

Are each of these Mouser reference usable for the MoBo ?

  • 805-51850NFJSLWADN

  • 805-51850NFQJLGACN

It seems, but it’s always better to ask :slight_smile:

Thanks !
Hédi K.

yup i got the green one (the second one)

Thanks !

Hédi K.

Hello I am sorry, I have remove from the project the 15 LED out of stock and the ATMega644p MCU, 20MHz by tipping error and I don’t know how to correct the project,… please can someone correct the project?

I went with the green-on-black Optrex neg. LCD. Been happy with it so far. Seems nice and bright, and no complaints about update speed. I also bought a VFD too, but the pinout is different, and I didn’t fancy hacking the mainboard around to make the hole bigger for it, and offsetting it, like Luap did.

The only thing that’s a bit odd about the Optrex part is the white plastic surround, which some might not like. It might be possible to lever if off, but I don’t mind it so I left it on.

I was tempted by the white-on-black, but resisted, because I was a little disappointed with the supposedly white neg. display that came with the Shruthi-1 4PM ‘semi-kit’. It was nice, but with the best will in the world, was blue…


I’ve ordered yesterday the green-on-black Optrex neg. LCD too. Did you put a 100ohm resistor as said before in this topic ? If yes, where ?

Hédi K.

100ohm’s should work just fine. I believe several people have used the same value with no issues.

On the back of the MoBo, top right of the LCD, just to the left of the trim pot pads is a spot for either a jumper or a resistor (labeled 8). Put the 100ohm there.

ordered a positive black/white optrex… I hope it’s nice … i thinking about a white case for it … maybe get some white leds for it too … only thing is there are almost no dual color leds with white in them.

@ qp
Thanks ! I’ve got it :wink:

Hédi K.

@shiftr: That display is killer. I built a project with the 4x20 version and it looked great. IIRC, thats transflective type so its easy to read during the day

…might it be that the Ambika-BOM is missing the 18pf-capacitors? - i was just getting to that step in the build-manual now and i cannot find the capacitors in the BOM…

They are listed as 22pF in the BOM ; but you can use 18pF too. I ship 18pF in the kit.

…ah! - ok, thank you for the quick reply and the info…i stopped soldering this afternoon and went to order the missing parts…so i’ll continue with the 22-ones now :o) …

…on a side-note: i noticed that the photos in the build manual show a different version of the MoBos…most obvious is the different numbering of the diodes between the photos and the current PCBs…

Yes some photos in the build instructions are from the older version - the only thing that has changed is the output amp section, and less importantly, the numbering of some parts.

I’ve got everything in Boards and Mouser order… i hope i made a right choice to go with a positive display… i think i should make a kind of test for it before i solder it in…