EXTINT

Matioupi asked 10 months ago

Is it possible to access the extint pin on the current PCB design ?
If not and you go to a v2 design some time ahead, i’d love to get access to this pin for synchronized event tmestamping

11 Answers
Best Answer
Ardusimple Staff answered 10 months ago

Hi Matioupi,

Yes this pin is not available in the current version. It’s a good idea to add it in the next generation, I add it to the candidate changes. May I ask you what do you want to use EXTINT for?

Matioupi replied 10 months ago

e.g. timestamping camera strobe pulse for accurate positionning of a photo event (without any digital data delay issues). That’s the usual way to procceed with high end gnss receiver and airbone cameras

clive1 replied 10 months ago

EVENTIN/TIMEMARK (EXTINT) is classically used in photogrammetry time-tagging and also to close the loop in time transfer applications.

fmbascon answered 8 months ago

Do you think to use one port to log the UBX PVT or NMEA and other port to get only the UBX-TIM-TM2 to store the time mark? I have read the multiport capabilities  on the “3.3.12 Communication ports” datasheet. So using two Sparkfun loggers must be work, don´t you?
I have not the Ardusiple at the moment but I need the interrupt pin too.

clive1 replied 8 months ago

UART2 cannot output UBX messages currently, only NMEA and RTCM3

balint.vanek answered 7 months ago

Do you have experience with the EXTINT pin? We are able to use is and it shows up both in u-center and in the .ubx file (after enabling TIM-TN2 messages) but we are missing some of the timemarks. We just directly connect the extint and ground to the hotshoe of a sony a6000 camera?

Ardusimple Staff replied 7 months ago

With this info is difficult to guess what is happening in your case, but we will share with you a few things you could investigate:
– TIM-TM2 message only shows the last 2 timemark events (rising & falling) between the previous and the current navigation output. This means that if you have the GPS configured at 1Hz and you shoot 2 times per second, the TIM-TM2 will only report the last one.
– When you increase the navigation rate to more than 1Hz, you need to be careful that you also increase the datarate of the communications (e.g. UART to 230kbps), otherwise a buffer overflow can happen on that interface.
– Try to make this camera to GPS connection as short as possible, if you use a long cable for this connection you have potentially more possibilities of noise on the line. If you have access to an oscilloscope it would be interesting to see how does the signal look at the pin of simpleRTK2B board.

Let us know if you find a solution and thanks for sharing it for the community. Looking forward to hearing good news!

skypuppy answered 7 months ago

It’s almost mid-April.  Is the new board shipping now?

Ardusimple Staff replied 7 months ago

Yes, we have been shipping the new version since the beginning of March 🙂

fmbascon answered 7 months ago

What is the resistor value between extint pin and the ublox chip on ArduSimple board? I need set up the interrupt wiring pinout trigger from Sony hot shoe. I think to use an optocoupler, Hot shoe and intpin at both sides.

Ardusimple Staff replied 7 months ago

Hi fmbascon,
there’s no resistor, the EXTINT pin on the board is directly connected to zed-f9p EXTINT pin. Protection and isolation needs to be added externally if needed.

fmbascon answered 7 months ago

Hello,
I have recorded the UBX-TIM-TM2 Time mark data message using the interrupt pin. Using 660 Ohm resistor. Wiring is INTPIN- 660Ohms resitor-ground. This is closed by a switch, optocupler, etc. But when convert the UBX file to rinex using RTKlib convert, no time stamps, mark, etc. Maybe the UTC time for UBX-TIM-TM2 is no good. Is the only possibility the HEX UBX file from “B5 62” header? See link files
Ublox and rinex files
UBX-TIM-TM2 HEX message
B5 62 0D 03 1C 00 00 F5 5C 0F 03 08 03 08 C7 73 µb…..õ\…..Çs
0010 F6 23 3E 1E 0C 00 C7 73 F6 23 1A E5 0A 00 36 00 ö#>…Çsö#.å..6.
0020 00 00 EF 16″

clive1 replied 7 months ago

Well you’d have to add back in the Leap Seconds to get to GPS TIME

—————————————————————————–
02 15 RXM-RAWX – E7 09 : E7 09 248
RXM-RAWX – TOW:601022.902 WEEK:2051 COUNT: 7 STAMP:19 5 4 22 57 2.9020000
Leap Valid 18
Reserved 01 26 C0 49190
M8 Version
GPS 1 L1CA 115812088.426 22038306.879 -2075.915 26 P C H 54700
GPS 3 L1CA 111851680.129 21284666.743 -1494.285 29 P C H 38700
GPS 11 L1CA 120340167.788 22899972.049 -3422.882 29 HALF P C H 64500
GPS 17 L1CA 115262137.445 21933655.642 662.848 22 P 0
GPS 18 L1CA 126274437.009 24029226.492 -3253.785 23 P 0
GPS 23 L1CA 112614242.482 21429777.426 1130.573 28 P C H 53880
GLONASS 4 L1OF 108188793.439 20203494.111 -2071.378 24 P 0
—————————————————————————–
0D 03 TIM-TM2 – 4D 81 : 4D 81 36
TIM-TM2 0 F5 1217
2051 601004886 460229 -> 601022.886460299 GPS
2051 601004886 404588
22
Running Mode
Armed
New Falling Edge Detected
New Rising Edge Detected
UTC
UTC available
Time is valid
—————————————————————————–
02 15 RXM-RAWX – 04 83 : 04 83 248
RXM-RAWX – TOW:601023.002 WEEK:2051 COUNT: 7 STAMP:19 5 4 22 57 3.0020000
Leap Valid 18
Reserved 01 8A C0 49290
M8 Version
GPS 1 L1CA 115812296.048 22038346.339 -2076.169 26 P C H 54800
GPS 3 L1CA 111851829.523 21284695.211 -1494.032 29 P C H 38800
GPS 11 L1CA 120340510.013 22900037.206 -3422.369 29 HALF P C H 64500
GPS 17 L1CA 115262070.160 21933642.757 662.848 22 P 0
GPS 18 L1CA 126274762.484 24029288.335 -3254.672 23 P 0
GPS 23 L1CA 112614129.376 21429755.933 1130.958 28 P C H 53980
GLONASS 4 L1OF 108188998.518 20203532.392 -2070.317 24 P 0
—————————————————————————–
02 15 RXM-RAWX – BF D8 : BF D8 248
RXM-RAWX – TOW:601023.102 WEEK:2051 COUNT: 7 STAMP:19 5 4 22 57 3.1020000
Leap Valid 18
Reserved 01 EE C0 49390
M8 Version
GPS 1 L1CA 115812503.558 22038385.862 -2074.932 26 P C H 54900
GPS 3 L1CA 111851978.899 21284723.643 -1493.841 29 P C H 38900
GPS 11 L1CA 120340852.225 22900102.363 -3422.092 29 HALF P C H 64500
GPS 17 L1CA 115262003.019 21933629.972 660.732 22 P 0
GPS 18 L1CA 126275085.925 24029350.036 -3256.466 23 P 0
GPS 23 L1CA 112614016.317 21429734.386 1130.723 28 P C H 54080
GLONASS 4 L1OF 108189205.567 20203571.102 -2071.758 24 P 0
—————————————————————————–