I have been building a speedometer and trying various different things just out of boredom mostly. One major issue I am experiencing is space! I am struggling to etch boards because I need to fit so many components on the board and the traces become so small I end up etching 5 boards before i get one that does not have a short or a etched off trace.
Currently I have a 2 digit LCD and I am using 2 CD4055BM chips to drive the LCD. in addition to this i am using a separate charge pump circuit to bump 3v coin cell to 5v for the LCD. In addition to this i have an atmega168 to drive the LCD driver chips. All in all Its a lot of components and I am sure there is a integrated solution i am just not too sure of it. Someone suggested a atmega169 to me and by the looks of it it could work. I see the atmega169 has capabilities to drive LCD's of up to 25 segments, I am just not sure yet if it could bump the voltagefrom 3v to 5v. One issue with this chip is that it's very expensive.
Could you guys please suggest a chip i could use to drive up to 2 segments (8 pixels/segment) with minimal components at a relatively cheap price?