Over the past few monts GNSS-disciplined opportunity hosts have already been trying out lots of my hobby opportunity

Compiled by John Miller

Strengthening and distribuiting the TimeHat went perfectly, and it provided me with a bit of higher funds to enjoy into several things that i would n’t have had the opportunity to normally, like getting some “real” GNSS timing segments! The system I was more contemplating was the Nokia FYGM, a GNSS timing device made to use Nokia cell webpages equipment. The FYGM features a u-blox LEA-M8T, among the best timing-focused u-blox modules readily available. A lot of people pick these (and various other) time segments from decomissioned mobile sites through Chinese scrappers and recyclers only to harvest the device, but i desired to keep them as “collectively” as you possibly can.

Unlike common hobbyist GNSS segments, the FYGM enjoys a some extra equipment about it, particularly an 8051 MCU. You will find more information on this on the wiki, here, thus I’ll bare this small. To begin, why not simply emancipate the M8T out of this panel? I’ve a number of factors:

  • I really don’t would you like to artwork a unique provider your M8T
  • The initial panel provides high quality power tools your M8T and energetic antenna
  • Additionally supplies exemplary antenna security circuitry
  • The integrated aluminium circumstances is actually good
  • The status LEDs (driven of the MCU) are helpful
  • The moment the panel footwear, you can obtain the MCU off our means

That MCU, the 8051, begun as the greatest thorn in my part. Before I had one of these brilliant products during my arms all I got to go off of was ebay listing photographs and a few articles regarding TimeNuts mailing list, but that has been adequate to begin. Besides antenna insight, the FYGM keeps one other connector – a 12 pin DIN amphenol-looking thing. Luckily all of the FYGMs i’ve discovered available inclide a completed cable to mate with this particular (using an HDMI connector regarding host product conclusion, with CAT7 because cable it self), if not this connector could possibly be an actual pain to deal with, becuase it isn’t an amphenol, or something that appears to be usually readily available. Merely 8 associated with pins on this connector are utilized, surface, DC in (using between 12 to 35v), following three RS422 differential sets for Tx, Rx, and PPS. Two RS422 transceivers on the bottom from the module supply this signaling. My personal initial goal were to try to make use of these as-is, therefore I had gotten some devices to utilize RS422 – much more about that later on.

TimeHat a?¤ Nokia FYGM

As soon as I got an FYGM during my palms, we started tracing the fittings and headers. I became disappointed to find out that the RS422 transeivers’ input does not are available right from the M8T, but alternatively it from 8051. This created it wouldn’t end up being spitting away UART signals right from M8T, a thing that ended up being genuine. About sugar daddies vibrant side, the four pin connector adjacent to the M8T try, in fact, UART right from the M8T, which means that skipping the 8051 seemed like a possibility, and it commercially ’s still. The ten pin connector next ot the 8051 was a programming and debugging header for the equipment, therefore possibly eventually I can see their configuration out as well as reprogram it making it a lot more useful to me personally. The greater number of instant use that header has may be the open reset pin – shedding a jumper between they and surface trigger the 8051 never to start anyway, therefore through UART pins near the M8T i will program along with it right, and entirely ignore the MCU. I didn’t wind up achieving this though.