This might be of interest, a single mixed signal chip, PSOC. This
might be a candidate to consider.
It has onboard Vref, OpAmps that can double as comparators, PGA,
SC/CT blocks that can also be used as comparators, DACs to gen
bias V, pulse stretcher, LED/LCD drive, and a whole lot more.
The DACs can be set under program control or thru logic control of
their DAC buss, logic to do so onchip.
This is a rough workup, some things not yet connected, of what
would be used. You darg and drop components onto canvas, config,
and use a wire tool to perform internal wiring and wiring out to pins.
Tool is PSOC Creator, it and compiler free. Board I think would be the
$ 15 board would suffice.
There is an arm processor in it as well if you want to do some advanced
features.
Attached is a catalog of chip components. In PSOC land a component is an onchip
resource.
Regards, Dana.