Uploaded September 2023 | Updated September 2026, 1 hour ago
Fifth part, about software oscillators, in which we learn a lot and achieve little …
↓↓↓ Complete description, time index and links below ↓↓↓
In the fourth video we’ve used an MCU to measure the frequency of an RC oscillator around a Schmitt-trigger inverter, that changes it’s frequency with the capacitance of our sensor (link below). But do we really need an external RC oscillator?
We first have a look at some ATmega datasheets. Next we code an oscillator relying on a GPIO pin’s Schmitt-trigger. We analyze why that didn’t work too well and switch to using an ATmega’s ADC instead. Finally we analyze why that is working only marginally better.
00:00 Intro – measuring capacitance with just an MCU
00:42 MCU GPIO pins – capacitance, leakage, Schmitt-trigger
03:10 Software RC oscillator 1 – based on a digital input
12:36 MCU GPIO hysteresis – very small and varying
22:53 Software RC oscillator 2 – based on ADC
30:26 Wrap-up – that didn’t go too well, bye
Tutorials youtube.com/playlist?list=PLwq-2MnM58FKn3920rc1V0qoTsQDheTIw
Capacitive Liquid Level Sensing (1): Sensor Basics youtu.be/Jjcym2g2ruk
Capacitive Liquid Level Sensing (2): Measuring Capacity (1) youtu.be/h6ErXsIQWDU
Capacitive Liquid Level Sensing (3): Measuring Capacity (2) youtu.be/v-1B_c-3KQ4
Capacitive Liquid Level Sensing (4): Analog to Digital (1) youtu.be/6-uRvu_0WW8
Capacitive Liquid Level Sensing (6): Analog to Digital (3) youtu.be/g8fjN2WKGN4
Capacitive Liquid Level Sensing (7): Reference Sensor (1) youtu.be/XDtQKoT6Zyo
Capacitive Liquid Level Sensing (8): Reference Sensor (2) youtu.be/pKZHFjDShpM
Capacitive Liquid Level Sensing (9): Dielectric Constant Not Always Matters youtu.be/iQqXeQJgLbc
Capacitive Liquid Level Sensing (10): Errata, Miscellaneous, The End youtu.be/TdAnryA6h-M
Rotary Encoders and Microcontrollers (e.g. Arduino) – My Way … youtu.be/nboGwG94hCw
My code drive.google.com/drive/folders/1nnl_Gb7OkkYhJTwuc848wvczO3PVb7s3?usp=sharing
#liquid #sensor #capacitance #capacity #capacitor #tutorials #tutorial #how-to #robertssmorgasbord
Fifth part, about software oscillators, in which we learn a lot and achieve little …
↓↓↓ Complete description, time index and links below ↓↓↓
In the fourth video we’ve used an MCU to measure the frequency of an RC oscillator around a Schmitt-trigger inverter, that changes it’s frequency with the capacitance of our sensor (link below). But do we really need an external RC oscillator?
We first have a look at some ATmega datasheets. Next we code an oscillator relying on a GPIO pin’s Schmitt-trigger. We analyze why that didn’t work too well and switch to using an ATmega’s ADC instead. Finally we analyze why that is working only marginally better.
00:00 Intro – measuring capacitance with just an MCU
00:42 MCU GPIO pins – capacitance, leakage, Schmitt-trigger
03:10 Software RC oscillator 1 – based on a digital input
12:36 MCU GPIO hysteresis – very small and varying
22:53 Software RC oscillator 2 – based on ADC
30:26 Wrap-up – that didn’t go too well, bye
Tutorials youtube.com/playlist?list=PLwq-2MnM58FKn3920rc1V0qoTsQDheTIw
Capacitive Liquid Level Sensing (1): Sensor Basics youtu.be/Jjcym2g2ruk
Capacitive Liquid Level Sensing (2): Measuring Capacity (1) youtu.be/h6ErXsIQWDU
Capacitive Liquid Level Sensing (3): Measuring Capacity (2) youtu.be/v-1B_c-3KQ4
Capacitive Liquid Level Sensing (4): Analog to Digital (1) youtu.be/6-uRvu_0WW8
Capacitive Liquid Level Sensing (6): Analog to Digital (3) youtu.be/g8fjN2WKGN4
Capacitive Liquid Level Sensing (7): Reference Sensor (1) youtu.be/XDtQKoT6Zyo
Capacitive Liquid Level Sensing (8): Reference Sensor (2) youtu.be/pKZHFjDShpM
Capacitive Liquid Level Sensing (9): Dielectric Constant Not Always Matters youtu.be/iQqXeQJgLbc
Capacitive Liquid Level Sensing (10): Errata, Miscellaneous, The End youtu.be/TdAnryA6h-M
Rotary Encoders and Microcontrollers (e.g. Arduino) – My Way … youtu.be/nboGwG94hCw
My code drive.google.com/drive/folders/1nnl_Gb7OkkYhJTwuc848wvczO3PVb7s3?usp=sharing
#liquid #sensor #capacitance #capacity #capacitor #tutorials #tutorial #how-to #robertssmorgasbord
