Power supply problems

Archive
1

Hey there,

at the moment I’m dealing with 2 problems:

  1. I’m using a barometer & usb-host-module to establish for communication with my android smartphone. When I start the fez spider by debugging it from visual studio, everything works fine: the connection to the android phone is established without problems. Hoverwhen I just start the spider without debugging, I have to reset it 100times bevor the connection works… Don’t know what’s wrong here… Do I have to change something at the configuration switches?

  2. Do you have suggestion, for a power supply with batteries? Do I need any extra circuits or whatever? I’m asking because my barometer module still measures false values, but only when I use a battery (9V block battery).

Thanks a lot :slight_smile:

2
  1. Can be a timing issues as well. Please show your code.
  2. There are some battery modules that were designed recently and probably will be available soon (search the forum). GHI has something in the works too.
3

I doubt a 9V battery can supply enough current for a mainboard, and if it could, it would not last very long, as most have a 200-300 mAh rating. They are not designed to discharge that quickly.

4

I’ve used a 9v to run my spider on plenty of occasions. Granted, it doesn’t last too long if I’m using more than a couple of modules, and it probably wouldn’t hold up well at all with numerous sensors, etc., but it seems to do fine for simple demos. If I need more, I typically switch to my wall wart.

5

I use a battery designed as a “USB emergency charger”, which works pretty well - mine is this one: http://www.amazon.co.uk/gp/product/B005JSG7GE/ref=oh_details_o03_s00_i01 - though I imagine there are any number of similar options that will supply USB-spec 5V for a reasonably high capacity (5600mAh). Also works powering Arduino, Raspberry Pi etc.