I am attempting to get a PPS signal from a GNSS microcontroller module called a TAU1302 Tiny EVK. The board gets a fix just fine with over 30 satellites all with an SNR above 25. The documentation says I am supposed to be seeing a blue LED light on the board indicating a PPS signal. I have never seen this occur. I have attempted to send a command to the board that sets the duty cycle and GPIO number for the PPS. Sending those commands has no effect.
These are NMEA GNGGA sentences that I see in addition to many other kinds.
$GNGGA,003741.000,4308.09191,N,07056.13286,W,1,14,0.89,52.9,M,-33.2,M,,*71 $GNGGA,003742.000,4308.09191,N,07056.13291,W,1,13,0.92,52.8,M,-33.2,M,,*78
Notice ,W,1,14,0.89 , and ,W,1,13,0.92
The 1 that I have placed in boldface is a number indicating what the documentation calls "GNSS quality indicator". I have attached an image from that portion of the documentation.
Notice "(values above 2 are 2.3 features)". No documentation, guide, nor hardware datasheet specifies what this "2.3 features" means. I have already contacted the company and received from them a firmware update. (they literally sent the file). I have flashed the new firmware onto this board. That again, had no effect.
I only ever see a 1 for this "GNSS quality indicator" even when using $200 tallysman antenna and having a fix on 38 satellites in a flat rural area getting SNRs above 40. I have also tried YIC L1/L2/L5 antennas, with the same null result.
Other documentation just simply says that this board will start sending PPS once it gets a fix, with no further elaboration. Nothing indicates that the board must be set to a special mode, or that it requires an initialization through the RX/TX serial connection, or anything of the like.
I have attached an oscilloscope onto the PPS line that exits from a tiny molex connection. This line produces a 2.5V square wave at 60Hz, under all conditions. Antenna, no antenna, outdoors, indoors, fix and no fix. Always just 2.5V 60Hz. So I know my material circuits are connected and operational. The board is just not doing what it is supposed to.
Does anyone know where I can go on the internet or who I could contact to try to get this thing to produce a PPS signal? Any suggestions are appreciated.
