Is the GPS chip you are considering compatible with all GNSS constellations? Does it also support dual frequency? I know it is more expensive, but positioning is really much more accurate using Galileo and dual frequency (which is also started to be deployed in GPS constellation).
Your hardware basis seems really interesting BTW, that’s just my two cents
@kalon33 I am targeting the BS-414Q module (GPS, GLONASS) for its small form factor and compass but I also have the larger BS-880 which has better sensitivity, compass and is good for up to three concurrent systems (GPS, Galileo, GLONASS, BeiDou). They will connect via a 6pin connector so you could use any module you want.
yes. I looked at that library (and even made the minor changes needed to get it working on the nrf52840. But I think I’m probably going to use the RadioLib project instead (we’ll see how that goes after I do my initial test). RadioLib seems a) more mature, b) more active development, c) lots of supported radio hardware. C is useful because it will allow me to write one adapter class for their API and then I can keep all of the existing fancypants queue management / sleep behavior and use either the current radio or the sx1262. Also a couple of people have asked about supporting semtechs 2.4Ghz chipset and they already support that chip as well.
Here is my board so far if anyone is interested. I am still waiting on a dual 18650 battery holder but the single will do for now. I am far from being a coder so I am slowly getting my head around PlatformIO and trying to get it to build successfully. I can’t wait to try them out with the huge link budget, especially as I have a couple of 5.15dB Moxon antennas to try as well!
Another thing is to figure out how to design a 3D printed case and make it!
Hi Paul, thanks! It all went together surprisingly well for the first prototype. I just hand soldered/hot air soldered this one together. The 0603 and SOT23-6 packages are about the limit by hand I think! It cost around $50USD to make including the GPS/compass module.
From what @geeksville has said the NRF52 package is more suited to this application than the ESP32 so I might look down that path and create a new board based on an NRF52 module. I never really considered having the boards manufactured in scale but based on the interest on this forum I should probably reconsider!
I did have to get QTY 10 PCBs made though so if you are interested in DIY I could always send you a board to populate.
Sadly the soldering requirements are a little outside my equipment but thanks for the offer. Thinking positively when you reconsider and come to the right conclusion I’d definitely be interested in some.
Thanks for the vote of confidence! I think I need to design a more polished version using a SMT NRF52840 module rather than the through hole ESP32. The ESP32 module didn’t expose the VBAT net so the battery connector needs to be un-soldered and a pin soldered on instead. Still works quite tidily though and I may make up the rest of the 10 boards I have and flick them on. Syeds board sounds like it should be good though.
I’m very interested in an, ideally, preinstalled solution. At this point I would just appreciate being able to buy from a reseller that’s a little closer to home selling a specific product version. When ordering from AliExpress, I never feel confident that I am going to get exactly what the description says.
If anyone creates new hardware, open it up for preorders to gauge quantities maybe.