lilimike
Member
Hi,
I am trying to figure out what I am doing wrong. I built an Ultrasonic distance meter based on the circuit from page 3 on THIS LINK, I got the Tx part to generate a 40KHz burst and with the Rx listening I get what I think should be the propper readings on the scope (CH1 is on U2 pin 2 and CH2 is on U2 pin 3) I get as expected
The part I start not understanding is when I read PIN1 of U2 which should give me a reading of 5 or 0 volts but I get this reading which is average -180 mV
Now this is without any capacitor, if I add a 1nF cap as suggested I simply get an average of -16mv.
Any help would be appreciated.
Mike
I am trying to figure out what I am doing wrong. I built an Ultrasonic distance meter based on the circuit from page 3 on THIS LINK, I got the Tx part to generate a 40KHz burst and with the Rx listening I get what I think should be the propper readings on the scope (CH1 is on U2 pin 2 and CH2 is on U2 pin 3) I get as expected
The part I start not understanding is when I read PIN1 of U2 which should give me a reading of 5 or 0 volts but I get this reading which is average -180 mV
Now this is without any capacitor, if I add a 1nF cap as suggested I simply get an average of -16mv.
Any help would be appreciated.
Mike
Last edited: