Sunday, May 5, 2013

Running OLinuXino-MAXI on Battery

Finally I've had some time to play with my new Olimex iMX233-OLinuXino-MAXI board, the board is similar to the Raspberry pi, almost the same size and cost, however, this one has an ARM iMX233 running at 454Mhz, less RAM and no GPU.

I played with the board for a while then I decided to test it using batteries, I found out that the USB/Ethernet physical is disabled when running on batteries ! After some digging around in the datasheet, there seems to be a way around this, by swapping two jumpers (3.3V_E and 3.3VIO_E) located near the reset button that control which DC-DC converter is used, the two possible configurations for those jumpers are:
  1.  External DC-DC: 3.3V_E closed (soldered), 3.3VIO_E open (unsoldered/cut)
  2.  On-chip DC-DC: 3.3V_E open (unsoldered/cut), 3.3VIO_E closed (soldered)

Note that the datasheet mentions that the maximum current that can safely be drawn from the on-chip convertor is 200ma and you need to make sure that you don't draw more than that, I'm not sure how exactly, but you should probably use one USB device at a time and either the USB or LAN.

It also mentions that the internal DC-DC makes the chip heat a little bit, so you may want to place a small heat sink on the processor.
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