Tiny RTK vs Smartnav RTK

In terms of performance (reliability, precision, also use/integration with Pixhawk), how do TinyRTK and SmartNav RTK compare (besides the weight difference) when used with Pixhawk?

I understand Smartnav uses the M8T and Edison for the RTKlib, vs TinyRTK that has the M8P that does it onboard, would the Smartnav boards be faster and/or ultimately more accurate and reliable?

Trying to decide which one to buy …

I would sum up features like this :

SMARTNAV :

  • completely open-source so it is easier to tailor to a specific use, Web based user-friendly interface
  • TCP, serial, USB connectivity
  • lots of parameters available, can be confusing when new to RTK
  • possibility to log on-board
  • possibility to post-process logs with RTKlib
  • quite heavy, energy intensive when WiFi is on
  • fully compatible with Pixhawk
  • time to fix : approximately 2-3 mins in good conditions
  • small support for integrity functions (better precision, less reliability without further fusion)

TinyRTK :

  • easy integration
  • serial connectivity
  • easy handling (you only have access to restricted number of parameters)
  • no raw data logging on-board, no post processing with u-blox algorithms
  • extremely small, low energy
  • fully compatible with Pixhawk
  • time to fix : approximately 4-5 mins in good conditions (u-blox has just released a new firmware improving these capabilities so it should be even better now)
  • integrity functions included (a little less precision, but better reliability as-is)

I have probably forgotten some features so feel free to ask any specific question about the systems.

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Thank you, helps a lot.

From what you are saying is it fair to say that SMARTNAV has less of a chance of loosing a fix in flight in less than ideal GPS environments, e.g. partial tree cover, etc, that TinyRTK?

Speaking of fix loss, can it still happen in “perfect” environments, e.g. wide open and flat space with full view of the sky, or is it mostly in urban environements, partial tree cover, etc? Also if it does, my understanding is that the rover unit of either SMARTNAV or TinyRTK simply revert to “plain” GPS until corrections are re-established with the base. In practical terms I’d think we’d be talking a few meters deviation at most for a Pixhawk multirotor or plane, is this typically the case?

It really depends, it means that SmartNav is more likely to give a “false fix” in difficult environments and that Tiny RTK will be more “aware” that it cannot output a precise solution under those conditions.

Again fix loss can happen if your setup is not tailored for having the best signal reception possible. Care must be taken to use good antennas, ground planes, etc… In that case fix should be held consistently. If base connection is lost, then units revert to “classical” GPS, deviation can be as little as 1meter if signal conditions are good!