Digital Analog Converter Chip: MCP4922, 2-channel, 12bit (also other versions available)
I used this DAC before and think it is a nice chip.
Datasheet:
https://www.mouser.de/datasheet/2/268/21897a-70809.pdf
Be sure to get the active LOW-Pins LDAC_ and SHDN_ right, LDAC_ to LOW/GND will trigger the conversion every time the CS_ is rised, so we can save one Pin on the Picomite. Tie SHDN_to VDD to have the chip work.
Here is some code which works for me and might get you started.
' MCP4922 Dual 12bit DAC
SetPin GP2,GP3,GP4,SPI
SetPin GP6, DOUT
Pin(GP6) = 1
SPI open 4000000,0,16
Do
For a% = 0 To 4096-8 Step 64
' CS Down (LOW Active)
Pin(GP6)=0
' DACn Write Buffer Gain_ Shutdown_
' DWBGS
junk = SPI(&B0111000000000000 + a%) ' 1st DAC
Pin(GP6)=1
Pin(GP6)=0
junk = SPI(&B1111000000000000 + a%) ' 2nd DAC
' CS
Pin(GP6)=1
'Print a%
'Pause 300
Next a%
Loop
SPI Close