Simple Rotator Interface V. assembled version (release 2024)
Web interface with MQTT an USB support
Quick start guide
Hardware
Supported:
Three type azimuth potentiometer
three wire from 500Ω to 10kΩ resistance
grounded two wire from 500Ω to 1kΩ
thre wire, used one turn from multiturn (typicaly 10kΩ)
Two azimuth pulse (CW/CCW) inputs - NOT implemented yet
DC motor up to 28V/3A with smooth start/finish (PWM)
AC motor max 50V/8A
Brake max 50V/8A
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Source
Functionality
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Remote
powered by POE - need 13,8V to 15V/500mA source, mounted to 35mm DIN rail

Switching between three and two wire azimuthpotentiometer in setup page
Enable preamp and shift op amp in setup page
Local control with CW paddle via 3,5mm stereo jack connector
Galvanically isolated AC or DC motor control, including DC PWM
Working rotator without hardware endstops - replace by two (low/high) software adjustable forbidden zones in end positions
MQTT for integrated to your main ecosystem, typicaly NodeRed
MQTT Wall - web clent shown all topics included
Overlap support, for example 405° range, with rotate to short direction
Usable nearest to rotator, directly on tower, or in hamshack
Status LED while using front panel preset knob (indoor desktop use only)
LED showing fuse failure on main board or POE interface

Three safe stop watchdog - 60 sec after firmware without answer, max 90 sec rotate, max 10 sec without 10 grad azimut change during rotate
Under 11V voltage POE power watchdog
Warm up timer for stable value during setup
Firmware detects the hardware version and displays it in the web interface
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Four mounting methods
Outdoor on tower
| Outdoor, part of the 3D printed rotator (optional)
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Indoor on 35mm DIN rail
| Indoor to your desktop (optional)
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Six control source at the same time
Web interface
with azimutal world map,
containing the current grayline
| Gyrotator
Optional controller on external hardware 5Stack FIRE
YouTube video | MQTT
(mqtt-wall include)
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USB GS-232 protocol
(commands: R L A S C Mxxx O F)
| CW paddle
- indoor desktop use
- or for manipulate with rotator on DIN rail, or on mount on tower
| Optional front panel preset knob
works independently without a GUI, together with the status LED (indoor desktop use only)
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WiFi e-ink display
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The last azimuth remains on the display even after turning off the rotator.
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It is not used to control the rotator, only to display its rotated state.
Web interface
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Adjustable width of the antenna radiation angle

Rotate with one click to map
If click during run, stopped rotation
Smaller range than 360° shows end limits

Show connected status between web page and rotator

Upload firmware
Upload binary via web interface
If the previous three conditions are met, you can upload the firmware binary using the web interface.
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Also available from the header of the first page as a link
| Upload FW |

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Upload .bin file via web form, with the
Firmware option selected

ATTENTION, after uploading, it is necessary to restart the rotator by disconnecting and reconnecting the power supply.
Compile
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Install these libraries in the versions listed
Select board 'OLIMEX ESP32-PoE'
Connect the rotator with a USB-C cable and select the corresponding port in the arduino IDE
Now you can compile and upload code using USB
Compile + OTA update
The firmware can be uploaded via Ethernet under the following conditions
The Simple rotator board already contains firmware
The Simple rotator board is connected to the Ethernet with a DHCP server
The Simple rotator board is powered by a POE module
Now in the Arduino IDE you can select the /Tools/Port/Network port in the menu, the item starting with ROT with the IP address corresponding to your rotator.
At this point it is possible to compile and upload the firmware using the Arduino IDE.
The Arduino IDE will ask for a password during the upload, which is 'remoteqth'.
Connection
General description of connectors, individual variants detailed below
POE power module
LED showing if fuse failure on main board or POE interface
Connection examples
Yaesu G-2800DX
TERMINALS
YAESU G800SA / G1000SA
Simple Rotator Interface V. is used as a replacement for the original control unit with its own DC power supply for the rotator motor.
Terminal connection according to the picture (above).
More about DC motor with PWM.
| Setup Web page basic settings - more | |
| Azimuth potentiometer | 3 Wire |
| Azimuth gain/shift op-amp | OFF |
| Hardware endstops | INSTALLED: ☑ |
| Motor supply | DC |
hy-gain HAM IV
Simple Rotator Interface V. is used as a replacement for the original control unit with its own AC power supply for the rotator motor.
Terminal connection according to the picture (above).
More about AC motor connetions.
| Setup Web page basic settings - more | |
| Azimuth potentiometer | 2 Wire |
| Azimuth gain/shift op-amp | OFF |
| Hardware endstops | INSTALLED: ☑ |
| Motor supply | AC |
ATTENTION - the POE injector must be powered from another source than the source for AC motor!
KENPRO KR-1000 / YAESU G800-G1000
Simple Rotator Interface V. is used as a replacement for the original control unit with its own DC power supply for the rotator motor.
Terminal connection according to the picture (above).
More about DC motor with PWM.
| Setup Web page basic settings - more | |
| Azimuth potentiometer | 3 Wire |
| Azimuth gain/shift op-amp | OFF |
| Hardware endstops | INSTALLED: ☑ |
| Motor supply | DC |
Azimuth potentiometer
Note the connection polarity for systems that share a GND potential
The
type potentiometer used must also be set in the web interface,
Setup page. Option “Azimuth potentiometer” 2wire/3-wire

When using one turn of a
ten-turn potentiometer, also
activate the “Azimuth gain/shift op-amp” option to ON. About calibrate more in
Calibrate section.
If you are using a
two-wire 500Ω potentiometer, short-circuit jumper J16 on the bottom side of the PCB.
Do not use this jumper in other cases.

AC motor
DC motor with PWM
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ATTENTION
Observe the polarity of the power supply, otherwise the power mosfet may be destroyed.
Observe the maximum prescribed loading.
We recommend using the following safe option with software endstops.
DC motor with PWM, without hardware endstop (safe mode)
If you use a rotator without hardware endstops, the destruction of one component (power mosfet) can cause the rotator to crash. Therefore, it is safe to connect one more active element in series (relay intended for the brake).
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ATTENTION
observe the polarity of the power supply, otherwise the power mosfet may be destroyed.
observe the maximum prescribed loading.
DC motor without PWM
PWM can be replaced with an external brake relay
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ATTENTION
Don't forget to bridge or replace the diode D24 with a jumper.
Make the
jumper with a copper wire with a cross-section of 1.5 mm
2

Control, setup and calibrate
LED status
LEDs signal static (PWR) or dynamic (PWM) states during rotator operation
Connect and tune
The fuse for the motor should be optimally 3A
Two blue, multi-turn potentiometers are used to set the Shift and Gain of the preamplifier in the azimuth measurement mode with the use of one turn from the ten-turn potentiometer.
The USB-c connector is used for uploading firmware or connecting a serial console. DO NOT use USB-C to power electronics.
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The 3.5mm stereo jack serves for connecting a manual control of the rotator, typically a
CW bug.

How to find the IP address of the device
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connect POE power supply
ethernet to a site with an active DHCP server
Variant via USB terminal
connect USB-C between rotator and PC
open Arduino terminal with 115200 baud speed
press ? and enter
terminal show your IP address

The variant can be found using the arduino IDE
Open Arduino IDE menu Tools/Port/Network port
The menu will display network devices that contain OTA firmware - the IP address is at the end of the line starting with
ROT-

With the help of the Fing android application
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Scan local network
Find device with brand name Espresiff and begin MAC start 08:B6:1F

Settings using the web interface
Main web page
Open the IP address found using the previous instruction in a web browser http://[YOUR-IP]
How to works
The first page contains an
information header, including a link to the
Firmware Upload page and the
Release page on GitHub. Give
green the button of the link to the control page of the rotator. Below it is the
web MQTT client (credit
MQTT wall) displaying the data sent or received by the rotator from the MQTT broker - data used to
control or debug the rotator.
This client requests an MQTT instance running on web socket port 1884.
Control web page
How to works
The basis for the display is an
azimuthal map, centered in your QTH. The map shows the current grayline. Map settings are made in the Setup page, item Background azimuth map
URL.
The direction of rotation indicator is a transparent triangle whose angle corresponds to the width of the antenna's radiation pattern. The center is marked with a green pointer on the scale. The width of the radiation diagram is set in the Setup page, item Antenna radiation angle in degrees.
COLORS - If the direction is in the free range, the indicator color is green. If the pointer reaches the overlap zone, the color is yellow. If the rotator is in rotated mode, the indicator color is red. If the rotator reaches the endpoints, the color is gray.
The yellow line on the edge shows the Overlap zone. It is the angle by which one 360-degree revolution is extended.
Gray bar on the bottom shows. | Antenna name - set in the Setup page, Rotator name item. | The power supply voltage controls the electronics from the POE injector - if it drops below 11.5V, the watchdog stops the rotator. | Raw angle rotated - angle without displacement, as if it were zero degrees north. | Link to the Setup page.
Below the gray bar is shown, MAC address of the Ethernet interface and website connection status with engine electronics. If it is not connected, the data on the website is not up to date and the rotator cannot be controlled.
CONTROL - by tapping on the map, the azimuth is calculated and the rotation starts. Emergency stop is performed by clicking anywhere on the azimuthal map again.
Tip: for a short movement of the rotator, you can click on the map twice in close succession. The motor will only turn on for this time, including the PWM start/stop sequence.
Setup web page
How to works
The Setup page is used to set the basic properties of the rotator.
You will notice that the hints for individual items are hidden under the question mark at the end of the line.
Your callsign and Rotator ID are unique identifiers used to generate an MQTT topic in the form [callsign]/[ID]/ROT/[variable]. Changing these values requires a reload of the first page with the web MQTT client. After the first power-on, for the Callsign firmware uses the last five characters from the MAC address until a new setting is made.
Rotator name is used to identify the rotator on the web control page.
Start CCW azimuth is the end value of the start of rotation in the counter clockwise direction. This is the azimuth that the rotator is rotated in real conditions, if it is in this end position.
Rotation range in degrees is the rotation range of the rotator between two (CCW and CW) endpoints in degrees.
Background azimuth map URL is a link to a web file with a bitmap azimuth map. Generation of own map is described in chapter
Run own services
Antenna radiation angle in degrees, is the value of the width of the radiation angle of your antenna, which will be applied in the display of the control page.
Azimuth source is a choice between a signal source for azimuth determination.
The Potentiometer is the default value.
The CW/CCW pulse function is then NOT implemented now.
The MQTT use topic ../RxAzimuth
The azimuth potentiometer is a choice between two and three-wire variants.
The two-wire variant uses a constant current source of 9mA and enables the connection of a potentiometer
smaller than 1kΩ. The
three-wire variant uses a constant voltage source of 9V and enables the connection of a potentiometer of
500Ω or more. You can find the connection in the
Azimuth potentiometer section.
Azimuth gain/shift op-amp, is turned ON, ONLY when using a multi-turn three-wire potentiometer, of which only one turn is used. Because one turn generates a small change at the input of the AD converter, it is possible to help amplify the preamplifier. How to do it:
The first step is to
set the trimmers R80 and R81 to the default position. Connect the ohmmeter to the measuring point S (J1, J12) and turn the trimmer R81 counterclockwise until the ohmmeter shows a value close to 0Ω. We repeat the same thing with trimmer R80 and measuring points and G (J13, J14).

This setting assumes that REVERSE-CONTROL and REVERSE-AZIMUTH are correctly set in the Calibration page.
The second step is to physically turn the rotator up to the CCW endstop, which will not cause the AD converter input to shift to the left edge of the scale on the Calibration page. Therefore, we start moving the value towards the left endstop on the scale by turning the potentiometer S (R81) clockwise until we reach the left endstop on the scale, ATTENTION, after reaching the edge of the scale, do not continue turning the potentiometer, the input value of the AD converter must still move within the range scale.
The third step is to physically turn the rotator up to the CW endstop, which will not cause the AD converter input to shift to the right edge of the scale on the Calibration page. Therefore, we increase the gain of the preamplifier by turning the potentiometer G (R80) clockwise until we reach the right endstop on the scale. ATTENTION, after reaching the edge of the scale, do not continue turning the potentiometer, the input value of the AD converter must still move within the range of the scale.
We repeat the previous two steps until we achieve the desired result.
Then calibrate the SAVE-CCW and SAVE-CW endpoints on the Calibration Page.
Endstops INSTALLED, turning off this item activates software endstops, which are prohibited zones on the edges. The size of these zones is set in the following two items. If this item is enabled, the firmware relies on the hardware endstops in the rotator, including that they are not beyond the range of the measure potentiometer.
CW/CCW forbidden zone (software endstops), are values of the range of forbidden zones in millivolts. the entire range of the rotator represents a voltage of 0 to 3.3V. The setting value will appear in the Calibration page as a yellow area at the edges of the range. If the rotator is set correctly, it only allows movement in the direction from the edge to the center. Keep the protection zone large enough to prevent damage to the rotator.
Watchdog speed is the minimum rotation speed in seconds per one turn, which if the rotator does not reach, it will be stopped by the watchdog. Use a value at least 50% higher than the real speed to avoid false stops.
Motor supply, is a choice between AC and DC rotator type. The DC type enables the activation of the PWM start-up and run-down ramps.
DC PWM control activates the PWM ramp-up and ramp-down when using the DC rotator. If you use a rotator without hardware endstops, the destruction of one component (power mosfet) can cause the rotator to crash. Therefore, it is safe to connect one more active element in series (relay intended for the brake).
This setup is highly recomended, see Connection section. Turning DC PWM on activates two other settings:
PWM ramp length in steps of 25ms + displaying the length of the ramp in seconds, allows you to set how long the PWM control will regulate from 0 to 100% during acceleration, or vice versa during deceleration - WARNING - a longer ramp may result in passing the end points, it is therefore necessary to set sufficiently large margins in CW /CCW forbidden zone (software endstops). In this way, imprecise stopping will occur more often due to the overlapping of the starting and stoping ramps when rotating through small angles.
PWM ramp start distance the distance from the target azimuth in degrees, from which the PWM ramp starts, the length of which is set by the previous value.
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If there is a need to rotate to a closer azimuth than twice the “PWM ramp start distance” value, there will be a switch from the starting to the stopping ramp halfway through the journey, which affects the stopping accuracy (missing the entire stopping sequence in the combination of time and distance). Therefore, it is better to choose both values as low as possible for your antenna assembly, so that it does not overlap the start and stop ramps.
USB serial BAUDRATE, is the setting of the communication speed of the serial console on the USB-C connector using the GS-232 protocol. Enabled commands
? display the IP address of the rotator
R clockwise rotation
L counter clockwise rotation
A or S CW/CCW rotation Stop
C show antenna direction value
Mxxx rotate to azimuth, degree represent with three number
O CCW calibration
F CW calibration
MQTT broker IP, IPV4 address of the MQTT broker server
If the first digit is zero, MQTT is disabled
MQTT broker PORT, number of the IP port on which the MQTT broker runs.
Change button, save actual value.
Calibrate button open Calibration web page.
Calibrate web page
Calibration is divided into three steps
Rotate direction calibrate
So that it is not necessary to observe the polarity of the rotator motor connection, you can use the CCW, CW and STOP buttons to test the direction of rotation. If the rotator rotates in a different direction than the control button, you can reverse the direction using the REVERSE-CONTROL button.
Azimuth calibrate
The scale shows the status of the input AD converter in the range of 0 to 3.3V. Due to activated software linearization, regions in the range of tens of mV are not available. If software endstops are activated in the Setup web page, the prohibited zones at the edges of the range will be displayed in yellow. In the lower part there is an arrow showing the current read value of the AD converter. There are gray arrows on the edges, showing the calibration values of CCW and CW stops. How to calibrate:
Turn the rotator briefly using the CW, CCW and STOP buttons in the previous section and watch the movement of the current value of the AD converter. The correct direction is left for CCW and right for CW. If the arrow moves in reverse, invert it using the REVERSE-AZIMUTH button
Then rotate the rotator counterclockwise until it is stopped by a software or hardware endstop. After stopping, save the value with the help of the SAVE CCW button.
Continue rotating the rotator clockwise until it is stopped by a software or hardware endstop. After stopping, save the value with the help of the SAVE CW button.
The RESET CW/CCW SAVE button is used to set the default values if the setting needs to be repeated.
After calibrate, rotate to full CCW limits, measure real azimuth, and put this value to “Start CCW azimuth:” field in Setup page.
Changes to settings in the map control page will be reflected after the page is reloaded.
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Rotate front panel potentiometer axis without knob to value 0°
Put knob with orientation to north on axis
Fixate knob to axis on position north
Control via optional front panel
The front panel contains only two active elements:
Button for setting the required azimuth - if the front panel is installed, turning the knob will make a quick change of the target azimuth, but it is not very accurate. The rotation of the rotator can be monitored on the control page of the web interface, or via MQTT, optionally also on the Gyrotator unit. Attention, the direction of the control knob on the front panel will no longer correspond to the real rotation of the rotator, if you change its azimuth from another source, for example from a web browser.
The status LED has three states
RED lights up during rotating.
GREEN lights up if the rotator has reached the set azimuth and stopped.
FLASHES GREEN if the rotator has stopped and has not reached the target azimuth.
Manually controll
Manual control is available via the 3.5mm stereo jack connector on the back of the electronics. By switching the left or right channel, it is possible to control clockwise or counterclockwise rotation. Connection is here.
Your CW key can easily be used as a switch control.
This control is suitable for service movements or if you operate the Interface on your desk.
Running own services
MQTT broker
MQTT is a universal protocol that is used to communicate the rotator with other devices. The control node transmitting this information is the MQTT broker. The default settings of the rotor use the public MQTT broker of the Internet at the address remoteqth.com. In order to avoid dependence on an Internet connection or the availability of a public MQTT broker, we recommend that you install your own MQTT broker on a Raspberry PI or other device in the local network. For this you can use some of the public instructions like this one (without installing NodeRed).
After installation, change the settings of two items (MQTT broker IP and MQTT broker port) in the Setup section, according to the IP address of your local MQTT broker.
Background azimuth Map generator with grayline
The RemoteQTH server provides a live grayline world map generation for selected DXCC countries at address https://remoteqth.com/xplanet/ (adding others upon request from OK1HRA). The entire path to the map is entered in the Setup page in the item Background azimuth map URL.
If you don't want to depend on the internet connection or remoteqth.com server functionality, you can run the real generator on any Linux machine, for example Raspberry PI. You need two functions for this:
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Script generating bitmap
Install xplanet with code
sudo apt install xplanet xplanet-images
Create line in /etc/crontab
*/15 * * * * web /usr/bin/xplanet -window -longitude 13.8 -latitude 50.0 -geometry 600x600 -projection azimuthal -num_times 1 -output /var/www/remoteqth/xplanet/OK.png
Where to replace | web user a valid user of your system | numerical coordinates of longitude and latitude with your requested coordinates | path /var/www/remoteqth/xplanet/ for the path published by your web server | file name OK.png for your desired file name
Enter the resulting path to the generated bitmap in the Background azimuth map
URL item on the
Setup page.
Online Map generator
Known bugs
If the continuous draw of your motor does not exceed the allowed limit, but the fuse still blows, the problem may be in the starting current. This current is naturally limited by the length of the power cable. If the problem persists even with the rotator on the mast, supplement the connection with a starting resistor (
B57237S0109M) in series with the rotator motor.