+-----------> Output | | |\ |\ |\ | |\ | \ | \ | \ | | \ | \ | \ | \ | | \ +--| >O------| >O------| >O----+-----| >O-----| | | / | / | / | / | | | / | / | / | / | | |/ |/ |/ |/ | | | | +5.0V | | | | | \ | | / R1 | | /| \ 10K | | / | / L1 | | / | | 75 uH | +----------------O< |--------+---+----------)()()()(------+ \ | | \ | / \| \ R2 / 10K \ | GND

.~ .~~~..~. : .~.'~'.~. : ~ ( ) ( ) ~ ( : '~'.~.'~' : ) ~ .~ ( ) ~. ~ ( : '~' : ) Raspberry Pi '~ .~~~. ~' '~'

+5 ---+---------------+---+ | | | R +----------+ |(see below) | 8 4 | +---+------+-----|7 3|------/\/\/\---+------- Vout : | | LMC555 | | C to test +-----|6 | ----- : | | ----- ground +-----|2 5|----+ | | | 1 | | ground | +----------+ 0.1 uF | | | Clock ----+ ground ground

__ o o MOSI o |()| o o o SCK RX_LED/SS o o o o MISO 1/TX o ICSP o VIN 0/RX o o GND RESET o o RESET GND o o +5V 2/SDA o o NC 3(PWM)/SCL o o NC 4/A6 o o A5 5 (PWM) o o A4 6 (PWM)/A7 o o A3 7 o o A2 8/A9 o o A1 9 (PWM)/A10 o o A0 10 (PWM) /A11 o o AREF 11(PWM) o _____ o 3.3V 12 (PWM)/A12 o [ ] o 13 (PWM) |___|

CMOS or HCMOS inverter |\ +--| >0---+----> OUT | |/ | | | +--\/\/\--+ | 1 Mohm | | | | \ | / 2.7 kohms | \ | / | | | 1MHz | parallel resonant +---|[]|--+ _|_ _|_ 55pf ___ ___ 60pf _|_ _|_ \ / \ /