NP-41 Emulator (may be)

[Chris Chung]

MEMORY LOST.

I had over-estimate my ability to hand solder SMD components (this one at 0.5mm pitch). After a failed PCB and a destroyed MCU ($15 dollar value), I managed to assemble my backup MCU (only ordered 2) and get it running.

There are a few missed pins when I turn on the power.

   
Another soldering session have all the segments light up.
   

I can't get the MCU charge pump working, so for now I am suck w/ no contrast control. I am not sure where the shadow segments came from, could be software or hardware. Hope I will be able to figure that out. The poor soldering may also contribute to ghosting.

Will be waiting for SMD capacitors to come in and try the on chip charge pump again. I have not yet soldering and code the keys yet. Still using UART (usb-serial) and a terminal for input. So the UART works and will allow us to download programs in the further. I am going to work w/ this rig and sort out the firmware 1st. Then have another PCB design. I feel that I need at least another engineering / prototype design before finalizing.

The most worry now is the quality of how I am driving the display. The ghosting is just too much. Have to rule out these possibilities.

. bad soldering.
. lack of precise bias control (due to no charge pump).
. software / firmware not optimized (timing and other control).
. LCD itself?