Raymarine Gyro Sensor Upgrade for $25

[gaw111]

Thank you for the info! I ordered one of the EVAL-ADXRS624Z and will update the outcome after the 1st of the year.

[olaf hart]

Any updates?

[gaw111]

I will be doing a sea trial on my boat this weekend and will post an update on how the gyro works.

[philocat]

Along similar lines you might want to look at a quadcopter controller. They sell ~$20-40, try hobbyking.com as a first stop or ebay for Chinese source. There are lots of alternatives around with available source code and apps such as multiwii- avr/arduino based,Openpilot- arm based, to name just two. Obviously designed for a quad but as they are they are very stable should eliminate any drift issues. They usually have a gyro, compass and accelerometer and baro chip/s all combined with kalman filtering and can be tuned by PC ap via usb. Perhaps an over kill for a boat but you could also use the baro for weather obs -or see how high you go on the swells?? Most also support two axis camera stabilisation and it is these outputs that I'd hook into as output to the autop; ok only one needed for an autopilot.

I got an email re this thread so maybe I contributed earlier to this thread but haven't looked back. I also recall Sean who contributes to OpenCPN discussing this on his autopilot design on a CF thread some way back.

[gaw111]

Ok, took the boat out this weekend and it passed the Autolearn process in the sea trial. I really didn't have any sea conditions to test it out on. If the response was set at 5 or above, it was too sensitive.

Now, on to the next item. I have an extra device if anyone is interested. Cost $65.00 plus shipping, I'll sell it for $60.00 plus shipping. The gyro is brand new and never used. If someone would like it setup and ready to plug in, I'll do that for $120.00.

If you would like anymore info, just ask. My email is gwheeler3@gmail.com

[George64]

If I'd like to upgrade my compass/nmea project (see several posts ago), what would be a good compass module as an upgrade? I'd like to improve the demping by making use of a Kalman filter. Any thoughts? The board will be the Arduino uno Rev3.

[olaf hart]

Any updates on available gyro sensors?

[becrux]

With the increasing popularity of drones and robots, there are lots of gyro sensors (and accelerometers and inertial sensors) out there. SparkFun isn't carrying any analog gyros right now, only digital output. Older autopilots want analog voltage levels from the gyro.

A search on "analog gyro" will give more hits than you care to wade through on Amazon and Ebay, and most are less than US$10 - get two; they're small... ;-)

If you aren't nerdy enough to pick one, get a nerdy friend. When I figure out what my old Wagner wants, I'll choose one and report back. Don't hold your breath.

Fair winds...

[sebba]

Hello there,

I just made a "Gyro Sensor" for my Raymarine Type 150 course computer.
Because I cannot find older gyro sensors with analog output, I used a new MPU9250 board, connected to an Arduino Nano.
The analog output use a MCP4725 DAC and the 5v power is provided by a MP1584 step Down 3A Adjustable Regulator.

It is more complicated than using an old analog gyro, thanks to progress and new technology, but I think it is still easy to make it and cheap...

I didn't test it already, I'm not on the boat right now, maybe in springtime I'll do it, but the output voltage seems to be what I need.

I also have one question: the output voltage is increasing when the boat (sensor) rotate to the right or to the left?

If somebody is interested, I'll post the schematic diagram and the code

Fair winds,
Seb

[becrux]

There may be simpler solutions. muRata makes Gyrostar, which has analog output. (It may require a simple op amp for the output.) It doesn't have all the digital features of the unit you suggest. There are only four pins, and it does only one axis. But do we really need more than that?
FWIW, I would guess that increasing heading would give higher voltage, and decreasing heading would give lower voltage. Just a WAG.

It would be interesting to see the schematic and code.

[sebba]

Thanks for your input.
I found that sensor on eBay. 80 USD for the cheapest one, plus shipping and so on...

I also hope the voltage is increasing when turning right and decreasing when turning left but I'm not 100% sure.
It is not specified not even in Raymarine service manuals

BR

[sebba]

This is the code I'm using right now.
I used an Arduino Pro Micro compatible board, not a Nano as I said before.
Should work with a Nano, too, but some lines have to be commented. The lines which turn on the LEDs.

It is still in RC stage, I'll check it when I'll be on the water
I'll put the schematic diagram a little bit later, I want to make it in Eagle or Fritzing...

Seb

/*
Advanced_I2C.ino
Brian R Taylor
brian.taylor@bolderflight.com
Copyright (c) 2017 Bolder Flight Systems

Adapted by Sebba for Raymarine Gyro Plus sensor. 2018.Oct.11
*/

#include "MPU9250.h"
#include <Wire.h>
#include <Adafruit_MCP4725.h>
Adafruit_MCP4725 dac;
uint32_t dac_value; //variabila de incarcare DAC
MPU9250 IMU(Wire,0x68); // an MPU9250 object with the MPU-9250 sensor on I2C bus 0 with address 0x68


	//optional, only for PRO MICRO boards which have ORANGE and GREEN LED oboard. 
	// comment the line below if you don't want to use the LEDs or you don't use a PRO MICRO board
	int RXLED = 17;  // only for Sparkfun Pro Micro
	// The RX LED has a defined Arduino pin // The TX LED was not so lucky, we'll need to use pre-defined macros (TXLED1, TXLED0) to control that.
	// (We could use the same macros for the RX LED too -- RXLED1, and RXLED0.)

void setup() {
//  Serial.begin(115200);

	//optional, only for PRO MICRO boards which have ORANGE and GREEN LED oboard. 
	// comment the line below if you don't want to use the LEDs or you don't use a PRO MICRO board
  pinMode(RXLED, OUTPUT);  // Set RX LED as an output - only for SPARKFUN PRO MICRO // TX LED is set as an output behind the scenes

  IMU.begin(); // start communication with IMU 
  IMU.setAccelRange(MPU9250::ACCEL_RANGE_2G); // setting the accelerometer full scale range to +/-8G 
  IMU.setGyroRange(MPU9250::GYRO_RANGE_250DPS); // setting the gyroscope full scale range to +/-500 deg/s
  IMU.setDlpfBandwidth(MPU9250::DLPF_BANDWIDTH_5HZ); // setting DLPF bandwidth to 20 Hz
  IMU.setSrd(199); // setting SRD to 19 for a 50 Hz update rate
  dac.begin(0x60); // start communication with DAC 
//  IMU.calibrateGyro();
//  delay(1000);
  IMU.setGyroBiasX_rads(0);
  IMU.setGyroBiasY_rads(0);
  IMU.setGyroBiasZ_rads(0);

//  Serial.print(IMU.getGyroBiasX_rads());
//  Serial.print("\t");
//  Serial.print(IMU.getGyroBiasY_rads());
//  Serial.print("\t");
//  Serial.print(IMU.getGyroBiasZ_rads());

}

void loop() {
  IMU.readSensor();   // read the sensor
  float Z = IMU.getGyroZ_rads()*180/PI;  // rad to degreees
  if (Z < -80) {Z = -80;} //limit output voltage at 80 deg/sec (for 2.5�2v output analog range)
  if (Z > 80) {Z = 80;} 
  dac_value = 2048+Z*2048/100; //transformare DPS in input (DAC 2048=2.5v) (2048+Z*0.025*4096/5)
  dac.setVoltage(dac_value, false);

	//optional, only for PRO MICRO boards which have ORANGE and GREEN LED oboard. 
	// comment these 2 lines below if you don't want to use the LEDs or you don't use a PRO MICRO board
  if (Z > 1) { RXLED0;  TXLED1; } else { TXLED0; }   //aprindem led-urile onboard din PRO MICRO - rosu (orange) pentru rotire spre babord
  if (Z < -1) { RXLED1;  TXLED0; } else { RXLED0; }   //aprindem led-urile onboard din PRO MICRO - verde pentru rotire spre tribord
  //delay (100); //10 raportari pe secunda
  //Serial.println(Z);

}

[sebba]

Schematic Diagram...

[becrux]

I'm sorry if "Gyrostar" was misleading. It is muRata's brand name and is not used much in their simpler products - only in the datasheet. You found the latest IG sensor. The one I was looking at is <$US5. Shipping to Romania will probably cost more.
This one already has the op amp.

https://www.amazon.com/TOOGOO-ENC-03...ds=Analog+gyro

Just search Amazon for "analog gyro" to see more low budget examples.
If you PM me your email, I'll send a nice pdf of the datasheet.

[sebba]

Ah, yeah, I know this little one, it is already on my list, at least for testing.
Will be a long winter with a lot of devices around me...
Thanks