2020-06-16, 08:56 AM
(This post was last modified: 2020-06-16, 03:28 PM by Barentsailor.)
I've been trying for a while to connect a MPU-9250 and a BME280 to a Raspberry pi 4 (4gb) running the last version of OpenPlotter.
1) First I've been trying to have both sensor in parallel in I2C, the IMU is located next to the RPI, but the BME280 is outside and I need to run a 2m long cable, so it's hard to get consistent I2C data. I had to play a bit with cable type and tried several values of pull-up resistors. In the end I get a result that is near acceptable, but I still get data corruption after about 24hours generally. So this is not reliable enough for sailing and I cannot reduce the cable length of my setup. Are there reliable solutions to run several I2C sensors in parallels?
2) I tried another idea and connected the BME280 to an arduino outputting the I2C data in NMEA0183 XDR sentences via USB to OpenCPN (see code here https://forums.ybw.com/index.php?threads/nanobaro-nmea-usb-barometric-sensor-easy-diy-electronics-project.484828). It works well and I can get the NMEA XDR sentences to the RPI's OpenCPN, but I cannot get it to SignalK. I tried both adding the USB NMEA0183 connection with the OpenPlotter interface as well as in Signal K directly, setting NMEA0183 and baud rate 4800, similar setup as I have in OpenCPN, but the data doesn't get to the server. I'm not familiar with connection types and ports, is there a way to get NMEA data directly via USB to SignalK as I do in OpenCPN?
I'd appreciate some help, it seems like a setup a lot of people would have, and would be interesting to know how others do.
1) First I've been trying to have both sensor in parallel in I2C, the IMU is located next to the RPI, but the BME280 is outside and I need to run a 2m long cable, so it's hard to get consistent I2C data. I had to play a bit with cable type and tried several values of pull-up resistors. In the end I get a result that is near acceptable, but I still get data corruption after about 24hours generally. So this is not reliable enough for sailing and I cannot reduce the cable length of my setup. Are there reliable solutions to run several I2C sensors in parallels?
2) I tried another idea and connected the BME280 to an arduino outputting the I2C data in NMEA0183 XDR sentences via USB to OpenCPN (see code here https://forums.ybw.com/index.php?threads/nanobaro-nmea-usb-barometric-sensor-easy-diy-electronics-project.484828). It works well and I can get the NMEA XDR sentences to the RPI's OpenCPN, but I cannot get it to SignalK. I tried both adding the USB NMEA0183 connection with the OpenPlotter interface as well as in Signal K directly, setting NMEA0183 and baud rate 4800, similar setup as I have in OpenCPN, but the data doesn't get to the server. I'm not familiar with connection types and ports, is there a way to get NMEA data directly via USB to SignalK as I do in OpenCPN?
I'd appreciate some help, it seems like a setup a lot of people would have, and would be interesting to know how others do.