Battery backup for GPS shield
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- wesg
- Posts: 118
- Joined: Thu Mar 18, 2010 10:00 pm
Battery backup for GPS shield
I just bought the GPS shield and receiver, with the plan of putting it in my car to do a little travel visualization. The last bit of the tutorial states that the Arduino and shield shouldn't be powered off without pulling the TX wire first. There is also a mention about a battery backup on the shield, so does that mean with the battery I can pull the power plug so that the buffer is written before shutting down? It would be great if there was something I could do to avoid pulling the TX wire each time.
- adafruit_support_bill
- Posts: 88091
- Joined: Sat Feb 07, 2009 10:11 am
Re: Battery backup for GPS shield
The battery backup is for the GPS module. It will not keep the SD card interface powered through the write cycle.
- wesg
- Posts: 118
- Joined: Thu Mar 18, 2010 10:00 pm
Re: Battery backup for GPS shield
Is there anything I can do to create a write buffer for when the power goes off?
- adafruit_support_bill
- Posts: 88091
- Joined: Sat Feb 07, 2009 10:11 am
Re: Battery backup for GPS shield
You could add a "shutdown" button to stop the sketch (and maybe light a led to indicate that it is stopped) and then turn off the power.
- wesg
- Posts: 118
- Joined: Thu Mar 18, 2010 10:00 pm
Re: Battery backup for GPS shield
That might work... what about a battery backup circuit that maybe uses a cap to provide power for a second or less? Is that a fairly simple circuit?
- adafruit_support_bill
- Posts: 88091
- Joined: Sat Feb 07, 2009 10:11 am
Re: Battery backup for GPS shield
That could work. But you need to make sure that the sketch is stopped before the cap runs out.
- wesg
- Posts: 118
- Joined: Thu Mar 18, 2010 10:00 pm
Re: Battery backup for GPS shield
Yep, that was my plan. I figure I'll try to use a pull-up resistor on one of the input pins to check for proper power, and enter a blank loop once the voltage drops. Thanks for your help, Adafruit support!
Please be positive and constructive with your questions and comments.