Dear Henrik,
Always when we speak about feedback than best solution is analog schematics.
Unfortunately, especially when needs to generate frequency in SWEEP MODE.
Start at 200KHz and go up with 10 Hz step until schematics find optimum.
When optimum frequency is found then needs continuously adjust frequency by monitoring voltage
on serial/parallel resonance output LC module and keep it close to zero.
Using traditional PIC architecture does not allow to do that.
So idea about dual core PIC with bridges between registers keeping variables is advance move in right direction.
Few words about USART. I read all literature and could not found how assigned
PORTB.Pin can send periodically variable values to serial LCD without involving
CPU resources for example 4 times per Sec.
About Propeller Chip: It is really good for gathering information, scaling data, and
sending data to storage.For me 8 CPU is too much and will never be using in any hobby applications
except special industrial ones.Will be better if manufacturer design
this chip with 2-4 cores and inner bridges between registers.It will give more freedom.
Best Regards to All