I am attempting to get a PPS signal from a GNSS microcontroller module called a TAU1302 Tiny EVK.?ÿ?ÿ The board gets a fix just fine with over 30 satellites all with an SNR above 25.?ÿ 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.?ÿ I have attempted to send a command to the board that sets the duty cycle and GPIO number for the PPS.?ÿ Sending those commands has no effect.?ÿ?ÿ
These are NMEA GNGGA sentences that I see in addition to many other kinds.?ÿ?ÿ
$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?ÿ?ÿ , 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".?ÿ?ÿ I have attached an image from that portion of the documentation. ?ÿ ?ÿ
Notice?ÿ "(values above 2 are 2.3 features)".?ÿ?ÿ No documentation, guide, nor hardware datasheet specifies what this "2.3 features" means.?ÿ I have already contacted the company and received from them a firmware update. (they literally sent the file).?ÿ I have flashed the new firmware onto this board. That again, had no effect. ?ÿ
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.?ÿ ?ÿ
Other documentation just simply says that this board will start sending PPS once it gets a fix, with no further elaboration.?ÿ 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. ?ÿ
I have attached an oscilloscope onto the PPS line that exits from a tiny molex connection.?ÿ This line produces a 2.5V square wave at 60Hz, under all conditions.?ÿ Antenna, no antenna,?ÿ outdoors, indoors, fix and no fix.?ÿ Always just 2.5V 60Hz. ?ÿ So I know my material circuits are connected and operational.?ÿ The board is just not doing what it is supposed to. ?ÿ
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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??ÿ?ÿ?ÿ Any suggestions are appreciated.?ÿ
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