P.S. Solar Power part deux
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Posts: 46,084
Clarification!
My first email may not be getting to the point:
1- I think I have a voltage leak...
2- I must have misunderstood something about Tracy Allen's setup because my
tx does not seem to reflect the actual readings I am making with my meter.
Thanks
Paul Ramirez Jonas
email prjnyc@m...
>From: "Paul Ramirez Jonas" <prjnyc@m...>
>To: basicstamps@egroups.com
>Subject: [noparse][[/noparse]basicstamps] Solar Power part deux
>Date: Thu, Mar 30, 2000, 12:54 PM
>
>Hello Everyone,
>
>Here is an update of my bell project and... a new set of problems
>
>In my project I have a stamp powered by a Solarverter Panel (9V, 150ma) in
>tandem with a Panasonic 6V 1.3 AH sealed acid battery. The stamp powers a
>RF transceiver and the there is a servo hooked in parallel to the set up. A
>LT1121CS8-ND regulates the power and avoids any power leakage back to the
>solar panels at night... Additionally I have a NPN and PNP set up powering
>the RF transceiver as needed. Why? the transceiver is very sensitive and
>will not run on power supplied by a Stamp pin set to HIGH... it really needs
>as close to 5V as possible. I am providing that out of the stamps pwr pin
>and use another pin to turn it on or off via the PNP and NPN set up...
>Finally, there is the servo. I am having trouble with it. It makes my
>stamp reset whenever it tries to power up and the voltage has dropped over a
>certain amount. When that happens the whole system spirals out of control,
>and is unable to set itself to sleep and uses up all of my battery... so
>taking a cue from the list, I am monitoring the voltage levels of the
>battery using the RCtime command. The idea is that if I can figure out when
>the voltage is to low the stamp will forgo activating the servo. AND in my
>attempts to isolate the servo from the system I am driving it through a ULN
>2803A, one pin controls the servo while another pin 'powers it up' through
>the ULN 2803A... Phew! So much for a simple solution -but it continues to
>be fun.
>
>Here is the set up:
>
>sleep
>wake up
>check voltage
>if OK power up Transceiver and wait for transmission else go to sleep for 15
>minutes
>when transmission arrives...
>check voltage again
>if OK run servo, strike bell else Joto sleep for 15 minutes
>
>
LT1121CS8
> | + | | |
>solar | + | |
>verter Battery |
|-1---ULN2803A
servo
>
> | _ | _ | | |
>
> | | |stamp|-0
|
>
> | | | | PNP |
>
> | | | |-2---NPN---Trans.----|
>
> | | | | | |
> | | |_____|--pwr-| |
> | | | |
>
>
>
>Is he use of the ULN 2803A misguided?
>is there a better way to isolate the servo?
>Does it sound reasonable to monitor the Voltage and decide to run the servo
>based on that?
>
>I am using the set up recommended by Tracy Allen:
>
> 470 ohm 100 kohm
> P0 ----/\/\/\---o
/\/\/\----Vx unknown voltage
> |
> ===== 0.1 uF film
> |
> Vss
>
>I use his code without a loop test program is:
>
> tx var word ' RCtime value
> vx var word ' voltage value to be determined
> Cn1 con 65000 ' first constant
> Cn2 con 14 ' second constant
>
>
>checkvolt:
>
> low 0
> RCtime 0,0,tx
> low 0
> vx=Cn1 / tx - Cn2 / 2
> 'if tx> than a certain amount return
> 'else sleep 15 minutes and back to checkvolt
>
>I am not even looking at vx and I am simply logging tx... but the results
>seem inconclusive. Sometimes the Stamp resets at a certain tx but at other
>times it seems fine at the same tx?
>
>Any ideas anyone? Is there something I am overlooking?
>
>Thanks in advance
>
>
>
>Paul Ramirez Jonas
>451 Broome Street #9W
>New York NY 10013
>Tel/fax 212.941.9941
>Mobile 917.744.2530
>email prjnyc@m...
>
>
>
>-- 20 megs of disk space in your group's Document Vault
>-- http://www.egroups.com/docvault/basicstamps/?m=1
>
>
My first email may not be getting to the point:
1- I think I have a voltage leak...
2- I must have misunderstood something about Tracy Allen's setup because my
tx does not seem to reflect the actual readings I am making with my meter.
Thanks
Paul Ramirez Jonas
email prjnyc@m...
>From: "Paul Ramirez Jonas" <prjnyc@m...>
>To: basicstamps@egroups.com
>Subject: [noparse][[/noparse]basicstamps] Solar Power part deux
>Date: Thu, Mar 30, 2000, 12:54 PM
>
>Hello Everyone,
>
>Here is an update of my bell project and... a new set of problems
>
>In my project I have a stamp powered by a Solarverter Panel (9V, 150ma) in
>tandem with a Panasonic 6V 1.3 AH sealed acid battery. The stamp powers a
>RF transceiver and the there is a servo hooked in parallel to the set up. A
>LT1121CS8-ND regulates the power and avoids any power leakage back to the
>solar panels at night... Additionally I have a NPN and PNP set up powering
>the RF transceiver as needed. Why? the transceiver is very sensitive and
>will not run on power supplied by a Stamp pin set to HIGH... it really needs
>as close to 5V as possible. I am providing that out of the stamps pwr pin
>and use another pin to turn it on or off via the PNP and NPN set up...
>Finally, there is the servo. I am having trouble with it. It makes my
>stamp reset whenever it tries to power up and the voltage has dropped over a
>certain amount. When that happens the whole system spirals out of control,
>and is unable to set itself to sleep and uses up all of my battery... so
>taking a cue from the list, I am monitoring the voltage levels of the
>battery using the RCtime command. The idea is that if I can figure out when
>the voltage is to low the stamp will forgo activating the servo. AND in my
>attempts to isolate the servo from the system I am driving it through a ULN
>2803A, one pin controls the servo while another pin 'powers it up' through
>the ULN 2803A... Phew! So much for a simple solution -but it continues to
>be fun.
>
>Here is the set up:
>
>sleep
>wake up
>check voltage
>if OK power up Transceiver and wait for transmission else go to sleep for 15
>minutes
>when transmission arrives...
>check voltage again
>if OK run servo, strike bell else Joto sleep for 15 minutes
>
>
LT1121CS8
> | + | | |
>solar | + | |
>verter Battery |
|-1---ULN2803A
servo
>
> | _ | _ | | |
>
> | | |stamp|-0
|
>
> | | | | PNP |
>
> | | | |-2---NPN---Trans.----|
>
> | | | | | |
> | | |_____|--pwr-| |
> | | | |
>
>
>
>Is he use of the ULN 2803A misguided?
>is there a better way to isolate the servo?
>Does it sound reasonable to monitor the Voltage and decide to run the servo
>based on that?
>
>I am using the set up recommended by Tracy Allen:
>
> 470 ohm 100 kohm
> P0 ----/\/\/\---o
/\/\/\----Vx unknown voltage
> |
> ===== 0.1 uF film
> |
> Vss
>
>I use his code without a loop test program is:
>
> tx var word ' RCtime value
> vx var word ' voltage value to be determined
> Cn1 con 65000 ' first constant
> Cn2 con 14 ' second constant
>
>
>checkvolt:
>
> low 0
> RCtime 0,0,tx
> low 0
> vx=Cn1 / tx - Cn2 / 2
> 'if tx> than a certain amount return
> 'else sleep 15 minutes and back to checkvolt
>
>I am not even looking at vx and I am simply logging tx... but the results
>seem inconclusive. Sometimes the Stamp resets at a certain tx but at other
>times it seems fine at the same tx?
>
>Any ideas anyone? Is there something I am overlooking?
>
>Thanks in advance
>
>
>
>Paul Ramirez Jonas
>451 Broome Street #9W
>New York NY 10013
>Tel/fax 212.941.9941
>Mobile 917.744.2530
>email prjnyc@m...
>
>
>
>-- 20 megs of disk space in your group's Document Vault
>-- http://www.egroups.com/docvault/basicstamps/?m=1
>
>