First, why did you change the two MCUs? Was damaged? is there any other device damage?
The K20 has the Open SDA, did you load the firmware on it?
You need it to program the KW40
No, i would like to make board , just like frdm-kw40z + Charging circuit.
and then MK20DX128VFM5 can not work. so i check power is ok but Oscillator pin no work .
1.i would like to know how to programming MK20DX128VFM5 ?
2. New component (MK20DX128VFM5) could programming by usb port?
thanks for your help