ESP8266 Community Forum

- Tue Apr 21, 2020 2:13 am #86688 So far I’ve established connection with my NodeMCU 8266 and Navionics Boating App. I achieved this by sending dummy NMEA depth data. As a next step I need to get my Helix 7 unit connected with ESP8266 so that I can read what it is sending out. With Google is was pretty easy task to find this pinout diagram and looking at the back of my device I can confirm that there is a similar connector and only 3 of the female holes are showing any copper so I think I’ve found the right diagram. I was a bit disappointed not to find +12v pin since that would have allowed me to get power for my ESP8266 using a DC voltage dropper. Well I can always power my device from any other +12v wires on my boat.

2020-04-21_10h07_33.png

http://forums.sideimagingsoft.com

Before I would be able to read any NMEA data from Helix 7 we need to turn on NMEA transmission from the unit. That is done by selecting menu button twice on my Helix unit -> settings -> turn NMEA on. Now that I know which of the pins is sending NMEA out and I know the ground pin as well, I took my multimeter, set it on DC and tried to read the voltage. It was jumping up and down as expected on the serial signal. So tweaked my multimeter a bit to capture max voltage. I was able to see max 3.0V. Repeated couple of times and was not able to capture anything above that. Since signal voltage is not above 3.0V I assumed that it’s safe to connect signal directly to ESP8266 since it’s running on 3.3V.

I really had hard time getting my head around all the different wiring diagrams that I found when trying to understand what needs to connect and where. So, I ended up making this diagram to document what I did. Powering my board from my boats USB charger.

2020-04-20_13h36_47.png

I then tried using this code to read what my unit was sending.

Code: Select allint data; //Initialized variable to store received data

void setup() {
  //Serial Begin at 4800 Baud
  Serial.begin(4800);
}

void loop() {
  data = Serial.read(); //Read the serial data and store it
  Serial.println(data);
}

I was expecting NMEA sentences but to my surprise I was seeing just numbers coming out from by Helix 7 unit. Mostly 3-digit numbers but sometimes also 2-digit or single digit. I think I’ve hit a wall. I have no idea what these numbers are or how to treat this data. Would someone have any idea?

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- Wed Apr 22, 2020 12:06 pm #86708 Any help would be highly appreciated from this community!

I double checked from this URL https://www.humminbird.com/support/faqs/how-do-i-output-digital-depth-information what data should be available. Connected my ground pin (black wire from Helix 7) and NMEA out (white wire) directly to my USB-serial converter on my PC according to wiring diagram.

2020-04-21_10h07_33.png

Then followed the instructions on the web site to load Tera Terminal. Turned local echo on, speed to 4800, data 8 bit, parity none, 1 stop bit and flow control to none. And started seeing NMEA data coming out as expected.

2020-04-22_13h47_23.png

So I think the right data is there. I'm not just reading and collecting it correctly so that I can print it via serial monitor.

Thanks again for any guidance on this one!

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- Wed Apr 22, 2020 2:05 pm #86713 Hi,

You have at least two problems as I see it.
1. The levels coming out the the Helix 7 are probably higher than 3 volts and maybe lower than ground. I doubt that the multi-meter will capture the high and low voltage. A scope would actually capture the actual waveform to verify the levels. Some kind of level shifting circuit is probably required between the Helix 7 and the ESP-12.
2. You have the output of the Helix 7 connected to RXD0 on the esp-12 development board. This pin is also connected to the Serial to USB IC on the ESP-12E board which talks to the USB port on your computer. I would use the other serial port ( UART) to connect to the Helix 7. There is lots of information on the internet on how to do this.
Mike

- Thu Apr 23, 2020 5:04 am #86720 Ive been trying to get my esp8266 to tx data into navionics for about 2 months but I'm no programmer. If you get this working PLEASE offer me some guidance. Im not sure if this helps or not but does the nmea library need to be included to parse the data? This code has a more simple lookin ui than the one i have been trying to get working.

This is the system i was trying to get to work: https://github.com/jcable/nmea-link
I've gotten it uploaded and have been able to see nmea data but i cannot get it to send to navionics. its not even showing as a "connectable" device when manually inputting the ip and port info. i wonder if your fix to that will work. Included in that firmware is a nmea simulator for testing purposes. I am able to see that and display the data in navionics and it works perfectly fine which is leading me to believe i dont have something in the connection settings right. That could possibly be fixed by the resolution you had. Maybe you can look it over and see what you think? IT also could be that i need the correct level shifter as the last person commented. I have been trying to use a rs485 to ttl converter and 'm not sure that will work.