RN4678 Does Not Enter Command Mode
P2_0 and P2_4 should be pulled high as you have in your schematic (but not necessary as the datasheet claims there are internal pull-ups), but the EAN pin (#20) needs to be pulled to GND for &quot;Normal Operation / Application Mode&quot;. Refer to Table 2-1 in the datasheet. Your configuration where all lines are pulled high is undefined.