What is the main purpose of this project?

To replace an unsightly coil cord on an ST4000+ autopilot with a wireless remote using 433MHz radios.

How does the system transmit data?

The transmitter sends an eight-byte message sentence containing a command and checksum at 9600 baud.

What microcontroller is used in the design?

The project utilizes a pair of PIC16F628 microcontrollers for both the transmitter and receiver.

Can the device run continuously without a power switch?

Yes, power-saving firmware allows it to run for several months on a single 9V battery without a power switch.

How is the wake-up sequence initiated?

The system wakes up by sending three consecutive 0xff bytes before the character J, S, F, and the message code.

What interface connects the receiver to the autopilot?

The receiver connects to the autopilot via Seatalk interface components.

Does the transmitter require a physical cable connection?

No, the transmitter is a standalone unit powered by a 9V battery and communicates wirelessly.

What frequency do the radio modules operate on?

The system uses 433MHz radio modules for communication between the handheld and stationary units.

Arduino PIC16F628: Wireless Remote for Raymarine ST4000

WIRELESS REMOTE CONTROL for Raymarine ST4000 Autopilot using PIC16F628

I had designed a remote unit for my ST4000+ autopilot. It did prove out the concept and I used it a lot, but it sported an unsightly coil cord (and of...

By Ibrar Ayyub

PublishedAugust 28, 2022

UpdatedNovember 22, 2023

Summary of WIRELESS REMOTE CONTROL for Raymarine ST4000 Autopilot using PIC16F628

This article describes a DIY wireless remote control for the Raymarine ST4000+ autopilot, replacing an old wired unit with a 433MHz radio system. The project uses two PIC16F628 microcontrollers paired with Parallax transmitter and receiver modules to enable keypress commands via a membrane keypad. Powered by a 9V battery with power-saving firmware, the handheld transmitter sends data to a stationary receiver connected to the boat's Seatalk interface.

Parts used in the Wireless Remote Control for Raymarine ST4000 Autopilot:

PIC16F628 microcontroller (pair)
Parallax 433MHz transmitter module
Parallax 433MHz receiver module
Antennas (for both Tx and Rx units)
Membrane keypad
Plastic box enclosure
9V battery
Seatalk interface components
10MHz XTAL oscillator
LED indicator

I had designed a remote unit for my ST4000+ autopilot. It did prove out the concept and I used it a lot, but it sported an unsightly coil cord (and of course unsightly coil cords have no place on boats) so I decided to build a wireless remote. The system (handheld Tx unit and stationary Rx unit) is based on a pair of microcontrollers and a pair of 433MHz radios.

The keypad/transmitter is on the left. It consists of a PIC16F628 microcontroller, Parallax 433MHz transmitter module ( and antenna, and membrane keypad built into the plastic box. It's powered by a 9V battery. Power saving firmward allows it to run continuously for several months...there is no power switch. The receiver is on the right (above.) It consists of a Parallax 433MHz receiver module and antenna, PIC16F628 microcontroller, and Seatalk interface components. Schematic and firmware details are below.

Code:

Code listing

/****************************************************************************

seatalk_wireless_remote_tx_1.c

This program is a remote control transmitter that sends a RxCx
number in an eight-byte message sentence with checksum.

Message protocol to the wireless receiver
* Each 9600 baud message contains a command and checksum:
   0xff    // wake up the transmitter and receiver
   0xff    // wake up the transmitter and receiver
   0xff    // wake up the transmitter and receiver
   'J'     // character
   'S'     // character
   'F'     // character
   cMsgCode   // which key was pressed
   'J' + 'S' + 'F' + cMsgCode   // equals checksum

                    +5
                    |
                    14
                ----------
      R4 ----6-| B0    A0 |-17-- out to Parallax 433MHz transmitter
      R3 ----7-| B1    A1 |-18-- out to LED
      R2 ----8-| B2       |
      R1 ----9-| B3       |
      C3 ---13-| B7       |
      C2 ---12-| B6       |
      C1 ---11-| B5       |
               |          |
 10MHz XTAL-15-|  16F628  |
       XTAL-16-|          |
                ----------
                     5
                     |
                    Gnd

          KEYBOARD ASSIGNMENTS
            C1      C2      C3
        +------------------------+
    R1  |      (cable here)      |
        |                        |
    R2  |                        |
        |                        |
    R3  |                        |
        |                        |
    R4  |                        |
        +------------------------+

***************************************************************************/

For more detail: WIRELESS REMOTE CONTROL for Raymarine ST4000 Autopilot using PIC16F628

What is the main purpose of this project?
To replace an unsightly coil cord on an ST4000+ autopilot with a wireless remote using 433MHz radios.
How does the system transmit data?
The transmitter sends an eight-byte message sentence containing a command and checksum at 9600 baud.
What microcontroller is used in the design?
The project utilizes a pair of PIC16F628 microcontrollers for both the transmitter and receiver.
Can the device run continuously without a power switch?
Yes, power-saving firmware allows it to run for several months on a single 9V battery without a power switch.
How is the wake-up sequence initiated?
The system wakes up by sending three consecutive 0xff bytes before the character J, S, F, and the message code.
What interface connects the receiver to the autopilot?
The receiver connects to the autopilot via Seatalk interface components.
Does the transmitter require a physical cable connection?
No, the transmitter is a standalone unit powered by a 9V battery and communicates wirelessly.
What frequency do the radio modules operate on?
The system uses 433MHz radio modules for communication between the handheld and stationary units.

Programmers & ICSP · PIC16F628A

DHT11 Low Cost Humidity Sensor using PIC16F628A with Proteus Simulation

IntroductionThis microcontroller project demonstrates how to interface a low-cost DHT11 temperature and humidity sensor with a PIC16F628A using a Proteus simulation environment.The...

LCD & Display Projects · PIC16F628A

Frequency Counter by PIC16F628

In this project we are building a basic and low cost frequency counter circuit . It can measure from 16Hz to 100Hz...

Games, Toys & Calculators · PIC16F628A

TIC TAC TOE game using PIC16F628

This project is not to introduce Tic Tac Toe. Everyone knows this game. It's to introduce two features. Bi-coloured LEDs, microcontrollers and...

Audio, Sound & Radio

Audio Spectrum Analyzer

We developed an audio spectrum analyzer as our final project for ECE 4760. This analyzer presented a histogram-style representation of audio signals....

Audio, Sound & Radio · PIC12F675

Audio CRO using PIC12F675 Microcontroller

This project is a miniature Audio CRO. For those not familiar with the abbreviation "CRO," it means "Cathode Ray Oscilloscope" and this...

Audio, Sound & Radio

Build a musical EKG with the Freescale FRDM-KL05

Short Introduction: I have been following the Battle of the DreamBoards Championship with interest and I enjoyed the variation of functionality features...

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough...