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---On May 2, 12:08 pm, gearhead <nos...@billburg.com> wrote:
On May 1, 2:42 pm, John Popelish <jpopel...@rica.net> wrote:
gearhead wrote:
On Apr 30, 2:55 pm, Randy Day <randy....@shaw.cax> wrote:
Just use your micro as a digital input; no analog required.
6-9vdc in --10K-----+------ micro
|
/\ 5v zener diode
|
Gnd
The output is DC, depends on the batteries voltage. But it is usually
6.4v.
Well I tried the circuit with the zener diode. I get 5v at the output.
But as soon as I place the microcontroller input pin, that voltage
just sink to 1.4v and the controller do not read it. If I put the
input pin directly on the output of the 7805 regulator (5v) then it
reads it as 5v. I used a 150ohm resistor afterwards, that did not
work. why is that
It seems that your microcontroller input is a fairly low resistance toThe output is DC, depends on the batteries voltage. But it is usually
6.4v.
Well I tried the circuit with the zener diode. I get 5v at the output.
But as soon as I place the microcontroller input pin, that voltage
just sink to 1.4v and the controller do not read it. If I put the
input pin directly on the output of the 7805 regulator (5v) then it
reads it as 5v. I used a 150ohm resistor afterwards, that did not
work. why is that ?
As an experiment:On May 2, 12:08 pm, gearhead <nos...@billburg.com> wrote:
On May 1, 2:42 pm, John Popelish <jpopel...@rica.net> wrote:
gearhead wrote:
On Apr 30, 2:55 pm, Randy Day <randy....@shaw.cax> wrote:
Just use your micro as a digital input; no analog required.
6-9vdc in --10K-----+------ micro
|
/\ 5v zener diode
|
Gnd
The output is DC, depends on the batteries voltage. But it is usually
6.4v.
Well I tried the circuit with the zener diode. I get 5v at the output.
But as soon as I place the microcontroller input pin, that voltage
just sink to 1.4v and the controller do not read it. If I put the
input pin directly on the output of the 7805 regulator (5v) then it
reads it as 5v. I used a 150ohm resistor afterwards, that did not
work. why is that ?
On May 1, 2:42 pm, John Popelish <jpopel...@rica.net> wrote:
gearhead wrote:
On Apr 30, 2:55 pm, Randy Day <randy....@shaw.cax> wrote:
Just use your micro as a digital input; no analog required.
6-9vdc in --10K-----+------ micro
|
/\ 5v zener diode
|
Gnd
crap, my pin was set to output...lerameur wrote:
On May 2, 12:08 pm, gearhead <nos...@billburg.com> wrote:
On May 1, 2:42 pm, John Popelish <jpopel...@rica.net> wrote:
gearhead wrote:
On Apr 30, 2:55 pm, Randy Day <randy....@shaw.cax> wrote:
Just use your micro as a digital input; no analog required.
6-9vdc in --10K-----+------ micro
|
/\ 5v zener diode
|
Gnd
The output is DC, depends on the batteries voltage. But it is usually
6.4v.
Well I tried the circuit with the zener diode. I get 5v at the output.
But as soon as I place the microcontroller input pin, that voltage
just sink to 1.4v and the controller do not read it. If I put the
input pin directly on the output of the 7805 regulator (5v) then it
reads it as 5v. I used a 150ohm resistor afterwards, that did not
work. why is that ?
As an experiment:
put the 10k resistor back in, and connect the
input end to the +5 supply for the micro.
Measure the voltage with and without the zener
in the circuit.
If the voltage stays at 1.4v, you've probably
got:
a) your input pin is actually programmed as an output pin
b) your input pin is actually programmed as something other
than a digital input (analog, clock in, etc).
c) a fried input to your micro.
A working digital input is said to be 'tied high'
with a 10k resistor; the voltage should be near +5.
If your voltage is 1.4 without the zener, the problem
is in the micro.
Can you hook a 10k to another input pin on the
device to compare?