Written by John Miller
Strengthening and distribuiting the TimeHat went very well, and it provided me with just a bit of further capital to look into a few things that I might not need had the capacity to normally, like picking up some “real” GNSS timing modules! The system I found myself a lot of contemplating was the Nokia FYGM, a GNSS time device designed to assist Nokia cell webpages products. The FYGM provides a u-blox LEA-M8T, among better timing-focused u-blox modules available. Plenty of people pick these (as well as other) timing segments from decomissioned mobile internet sites through Chinese scrappers and recyclers simply to harvest the device, but i needed to make sure they’re as “together” as it can.
Unlike common enthusiast GNSS modules, the FYGM has actually a little extra components about it, particularly an 8051 MCU. We have additional information on this about wiki, right here, thus I’ll bare this short. To start, why not merely emancipate the M8T with this panel? We have certain grounds:
- I really don’t desire to artwork a unique company for all the M8T
- The first board have premium energy products for all the M8T and active antenna
- It also supplies outstanding antenna safeguards circuitry
- The included aluminium case is really nice
- The updates LEDs (pushed because of the MCU) are of help
- The moment the board boots, it’s not hard to obtain the MCU regarding our means
That MCU, the 8051, begun as being the most significant thorn in my side. Before I got one of these simple devices in my palms all I experienced to visit off of was ebay listing pictures and a few posts on TimeNuts subscriber list, but which was sufficient to get started. As well as antenna input, the FYGM provides an added connector – a 12 pin DIN amphenol-looking thing. Luckily all of the FYGMs i’ve discovered for sale inclide a completed wire to mate using this (using an HDMI connector regarding the variety tool end, with CAT7 given that wire alone), or else this connector could possibly be a proper pain to manage, becuase it isn’t an amphenol, or whatever appears to be normally available. Best 8 of this pins about this connector are used, soil, DC in (having from 12 to 35v), and three RS422 differential sets for Tx, Rx, and PPS. Two RS422 transceivers toward the base associated with module provide this signaling. My initial objective was to try and use these as-is, and so I had gotten some equipment to work alongside RS422 – regarding that later on.
TimeHat a?¤ Nokia FYGM
Once i obtained an FYGM in my fingers, we began tracing all the connectors and headers. I was dissatisfied to find out that the RS422 transeivers’ input doesn’t come right from the M8T, but alternatively they from the 8051. This intended it probably wouldn’t become spitting around UART signals straight from M8T, something that ended up being real. On the bright side, the four pin connector next to the M8T is actually, indeed, UART straight from the M8T, which means that bypassing the 8051 seemed like the possibility, also it officially ‘s still. The ten pin connector next ot the 8051 is a programming and debugging header for this device, very maybe one day I’m able to browse its setup out or even reprogram they to make it much more useful to myself. More quick incorporate that smooch DATING-apps header has actually is the uncovered reset pin – falling a jumper between it and ground produces the 8051 never to start after all, therefore through the UART pins next to the M8T I am able to interface along with it right, and entirely ignore the MCU. I did not find yourself carrying this out though.