Although you have configured the pin as an input, have you turned off the
pull-up resistor?
-----Original Message-----
From: p_anglum [mailto:p_anglum@hotmail.com]
Sent: 22 June 2004 19:57
To: AVR-Chat@yahoogroups.com
Subject: [AVR-Chat] A/D to PWM
I'm using a Tiny 15 to convert a 0-10 volt input to
PWM output.From: p_anglum [mailto:p_anglum@hotmail.com]
Sent: 22 June 2004 19:57
To: AVR-Chat@yahoogroups.com
Subject: [AVR-Chat] A/D to PWM
I use a voltage divider (10K - 10K) to scale the 0-10 down to 0-5
before applying it to PB3(ADC3).
Everything seems to work except at the lowest range of input voltage
the A/D seems to always read some small voltage. In fact, with my 0-
10V input removed and only the voltage divider on the input to to
ADC3 I read about .9 volts on ADC3. It appears the source of the
voltage is the ADC3 pin itself. Any ideas?
(All voltage measurements were made in refernce to pin4 - GND on the
Tiny15)