Removed test_21_adc with library
Complete the modem power-up and down
fix power on/off modem
add +CSMINS example text.
add modem test with play all synth
add test modem <-> serial with fixes
add wind lib with test
fix prescaler, switch pwm to 32Khz.
pwm define PSC and ARR as const
1st test on adc channel 6.
add copyright and schematics.
enable internal MISO pullup.