Battery voltage reading
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Posts: 46,084
Vince--
I use a resistor divider to make the measurement. What I do is connect one
end of a ten Megohm resistor to the + battery term. The other end of the
ten Mohm resistor goes to a one Megohm resistor, the other end of the one
Mohm goes to ground. (This divides the actual reading by a factor of ten.)
Where these two resistors meet, I connect to the input of an LTC1298 A-D
convertor. Then in my code, I tell the stamp to bring in the measurement
every so often.
Certainly not the only way, or best way, but it works for what I need.
--Don
>
Original Message
> From: Vince Fell [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=5qypxg-B6QGSrcFdponJTpY8J7kyiexnza9fL4kVGeIfayQzHENJH5Bk-j-R9ZUvyy8DJshvu6Q]alhvgf@t...[/url
> Sent: Monday, September 25, 2000 1:35 PM
> To: basicstamps@egroups.com
> Subject: [noparse][[/noparse]basicstamps] (unknown)
>
>
> I am using a BSII as a driver interface on a Barbie Jeep.
> Unfortunately there is no way to see the current state of charge in
> the batteries. Any ideas on how to use the stamp to pull this off?
> I am using an LCD display on the Jeep to display other functions
> which could be used to display current battery state.
>
> Thanks in advance for your advice!
> VF
>
>
>
I use a resistor divider to make the measurement. What I do is connect one
end of a ten Megohm resistor to the + battery term. The other end of the
ten Mohm resistor goes to a one Megohm resistor, the other end of the one
Mohm goes to ground. (This divides the actual reading by a factor of ten.)
Where these two resistors meet, I connect to the input of an LTC1298 A-D
convertor. Then in my code, I tell the stamp to bring in the measurement
every so often.
Certainly not the only way, or best way, but it works for what I need.
--Don
>
Original Message
> From: Vince Fell [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=5qypxg-B6QGSrcFdponJTpY8J7kyiexnza9fL4kVGeIfayQzHENJH5Bk-j-R9ZUvyy8DJshvu6Q]alhvgf@t...[/url
> Sent: Monday, September 25, 2000 1:35 PM
> To: basicstamps@egroups.com
> Subject: [noparse][[/noparse]basicstamps] (unknown)
>
>
> I am using a BSII as a driver interface on a Barbie Jeep.
> Unfortunately there is no way to see the current state of charge in
> the batteries. Any ideas on how to use the stamp to pull this off?
> I am using an LCD display on the Jeep to display other functions
> which could be used to display current battery state.
>
> Thanks in advance for your advice!
> VF
>
>
>
Comments
>Vince--
>I use a resistor divider to make the measurement. What I do is connect one
>end of a ten Megohm resistor to the + battery term. The other end of the
>ten Mohm resistor goes to a one Megohm resistor, the other end of the one
>Mohm goes to ground. (This divides the actual reading by a factor of ten.)
>Where these two resistors meet, I connect to the input of an LTC1298 A-D
>convertor. Then in my code, I tell the stamp to bring in the measurement
>every so often.
>Certainly not the only way, or best way, but it works for what I need.
>--Don
Not to be a nit picker, but... Your resistor divider values should give you
one eleventh of the battery's voltage, not one tenth. A ratio of 9:1 in
resistor values would give you one tenth.
--
Greg