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LPS and LPS Mini are now compatible with TREK1000

A project log for LPS Mini

Arduino compatible indoor navigation system with small form factor.

gran-nordahlGöran Nordahl 01/12/2016 at 21:020 Comments

LPS can now work as a TREK1000 compatible tag if used in 110k mode! Even the DIP switch settings are identical. http://www.decawave.com/products/trek1000.

LPS Mini normally runs at half the speed compared to LPS (8 MHz instead of 16 MHz) and can thus not reply quick enough to work with TREK1000. It is possible though to increase the clock frequency to a maximum of 13.33 MHz and still stay within the safe operating area (LPS Mini runs at 3.3V):

Closest standard crystal frequencies below 13.33 MHz are 13, 12.288 and 12 MHz. Baud rate errors are then 0.76% (13 MHz), 2.6% (12.288 MHz) and 0.16% (12 MHz) when generating 115.2 kbps. To get some extra headroom we recommend going for 12 MHz. 7A-12.000MAAE-T from TXC Corporation is a drop in replacement for the existing 8 MHz crystal (7A-8.000MAAJ-T).

12 MHz is not needed for our own demo firmware, but from now on LPS Mini will be shipped with a 12 MHz crystal and our demo source code package will come with a 8/12 MHz define. Next release will also contain three different bootloaders (one each for 8, 12 and 16 MHz) and firmware hex files for TREK1000 compatibility.

If you have previously bought a LPS Mini from us we can offer an upgrade to the cost of the crystal and freight back to you. Please note that this is only needed if you want your LPS Mini to be a TREK1000 compatible tag @ 110 kbps.

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