Battery measurement help

Archiver

An alternative to adding ADCs is to use a digital switch. One example isthe Maxim 333A, which has 4 DPST switches.· Then use the BS2 to logicallycontrol the switch to select a particular channel.· This is more versatilethen using a multiplexer, because you can control the logic in a non-sequentialmode, which your application requires.
Dennis



Don Bannon wrote:

[size=-1]HelloGroup--[/size][size=-1]I have a stamp2 alternatelyreading "data out" on two A to D convertors, first one, then the otherand repeat.· After each is read 20 or 30 times, I want to read a thirdADC that measures the battery supply voltage to the circuit.· Thiswill tell me when the battery should be changed.[/size][size=-1]I'mthinking of using another ADC to read this supply voltage and the codeto kick out of the main loop after 20 or 30 readings, read the voltagefrom the third ADC, then go back into the main loop to do another 20 or30 readings.[/size][size=-1]Would any ofyou be able to provide me with a sample of the code needed to do jump outafter 20 or 30, read the third ADC and go back ito the main loop?[/size][size=-1]Hasanyone had experience doing this before from a hardware standpoint?[/size][size=-1]TIAfor any help.·· --Don[/size]

Archiver

Hello Group--
I have a stamp2 alternately reading "data out" on two A to D convertors, first one, then the other and repeat.· After each is read 20 or 30 times, I want to read a third ADC that measures the battery supply voltage to the circuit.· This will tell me when the battery should be changed.
I'm thinking of using another ADC to read this supply voltage and·the code to kick out of the main loop after 20 or 30 readings, read the voltage from the third ADC, then go back into the main loop to do another 20 or 30 readings.
Would any of you be able to provide me with a sample of the code needed to do jump out after 20 or 30, read the third ADC and go back ito the main loop?
Has anyone had experience doing this before from a hardware standpoint?
TIA for any help.·· --Don

Archiver

Tracy Allen's Excellent web site has an application using RC time for
measuring battery voltage

http://www.emesystems.com/BS2misc.htm#RCtime

I recently tried it out and it works perfectly, of course!

Steve




At 12:17 PM 08/24/2000 -0700, you wrote:
> This is more versatile then using a multiplexer, because you can
>control the logic in a non-sequential mode, which your application requires.
>Dennis
>
> Don Bannon wrote: Hello Group-- This will tell me when the battery
>should be changed.I'm thinking of using another ADC to read this supply
>voltage and the code to kick out of the main loop after 20 or 30 readings,
>read the voltage from the third ADC, then go back into the main loop to do
>another 20 or 30 readings.Would any of you be able to provide me with a
>sample of the code needed to do jump out after 20 or 30, read the third ADC
>and go back ito the main loop?Has anyone had experience doing this before
>from a hardware standpoint? --Don
>

Archiver

Why not use one of the multi-channel ADCs - one chip most likely means less
power and everything can be done within one loop. Something like:

maxct = 20
ct = 0
READADC:
read chan1
read chan2
ct = ct + 1
if ct < maxct then skipnext
read battchan
ct = 0
SKIPNEXT:
goto READADC

I hope this helps

Vic
_____________________________________________________

Victor Fraenckel - The Windman vfraenc1@n...
KC2GUI
www.windsway.com

Home of the WindReader Electronic Theodolite
Read the WIND

Archiver

Dennis--· Thanks for your help on my measurement problem.· Much appreciated.· --Don

---

Original Message

---

From: Dennis O'Leary [noparse][[/noparse]mailto:doleary@hsc.usc.edu]
Sent: Thursday, August 24, 2000 2:17 PM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Battery measurement help

An alternative to adding ADCs is to use a digital switch. One example is the Maxim 333A, which has 4 DPST switches.· Then use the BS2 to logically control the switch to select a particular channel.· This is more versatile then using a multiplexer, because you can control the logic in a non-sequential mode, which your application requires.
Dennis
·
·

Don Bannon wrote:

[size=-1]Hello Group--[/size][size=-1]I have a stamp2 alternately reading "data out" on two A to D convertors, first one, then the other and repeat.· After each is read 20 or 30 times, I want to read a third ADC that measures the battery supply voltage to the circuit.· This will tell me when the battery should be changed.[/size][size=-1]I'm thinking of using another ADC to read this supply voltage and the code to kick out of the main loop after 20 or 30 readings, read the voltage from the third ADC, then go back into the main loop to do another 20 or 30 readings.[/size][size=-1]Would any of you be able to provide me with a sample of the code needed to do jump out after 20 or 30, read the third ADC and go back ito the main loop?[/size][size=-1]Has anyone had experience doing this before from a hardware standpoint?[/size][size=-1]TIA for any help.·· --Don[/size]

Archiver

The structure should be something like this:

I var byte 'variable to count

main:
for i= 1 to 30
gosub readADC1
gosub readADC2
next
gosub readBatt
goto main

readADC1:
'put code to read here
'do something with result
return

readADC2:
'put code to read here
'do something with result
return

readBatt:
'put code to read here
'do something with result
return

ACJacques


Don Bannon wrote:
>
> Hello Group--
> I have a stamp2 alternately reading "data out" on two A to D
> convertors, first one, then the other and repeat. After each is read
> 20 or 30 times, I want to read a third ADC that measures the battery
> supply voltage to the circuit. This will tell me when the battery
> should be changed.
> I'm thinking of using another ADC to read this supply voltage and the
> code to kick out of the main loop after 20 or 30 readings, read the
> voltage from the third ADC, then go back into the main loop to do
> another 20 or 30 readings.
> Would any of you be able to provide me with a sample of the code
> needed to do jump out after 20 or 30, read the third ADC and go back
> ito the main loop?
> Has anyone had experience doing this before from a hardware
> standpoint?
> TIA for any help. --Don