mySunTracker - Single Axis Programmable Solar Tracker
Please Note: I have decided to donate this to the web and stop selling it....I have put a schematic, PIC code at bottom of page. This is a robust, fully functional controller working in the field. Enjoy.
mySuntracker is a single axis solar tracker designed around a small microprocessor. It has programmable duty cycle, on time, park modes, and manual motor control support.
It is designed to give great solar tracking performance and provide several advanced features at an inexpensive cost point of only $65 fully assembled.
1. Single Axis Solar Tracking Control with H-Bridge Output
2. Programmable Auto Park at night - East / West or No Park selectable
3. Programmable Motor On Pulse Width - eliminates over shoot and reverse inhibit needs
4. Programmable Solar Sensor Sensitivity - minimizes wander during clouds
5. Programmable Motor Duty Cycle - controls tracking update rate.
6. Two programmable auxiliary inputs that can be programmed to be limit switch stops, manual motor control for East / West movement, or emergency park/open motor inputs
7. Manual H-Bridge Motor Control with push buttons or external header pin inputs
8. H-Bridge FETS rated at 8A max, up to 30V battery operation, current protected
9. LED Indicators for East or West Movement, Mode and Parameter Setting Feedback
10. +12V, +24V powering options, very low power consumption, H-Bridge Low Voltage Shutdown
11. Screw Terminals for power input and motor connections, MTA-100 for control inputs.
12. All settings are stored in non-volatile memory and return after power removal.
mySunTracker Modes of Operation
The mySunTracker supports 5 modes of operation. Changing modes is accomplished by pressing the S1 and S2 push-buttons simultaneously for about 1 second. This will step thru the operating modes of the mySuntracker one by one. Each time a new mode is selected, both LEDs will blink simultaneously, counting out the new mode number (1 - 5 times) selected.
Mode 1: Normal Run Mode - This is for normal solar tracking operation.
Mode 2: Programming Mode - This is for configuring the different parameter settings and adjusting the operation of the mySunTracker.
Mode 3: Manual Control Mode - This mode allows the two push buttons to control the H-Bridge, allowing manual control of the motor. S1 moves the motor one direction, S2 moves the motor the other direction. The operation of the motor is pulsed.
Mode 4: Park Mode - This mode will force the motor to park in the direction you can configured the Park Mode (either East or West). If you have configured it not to park (NO Park), this mode will do nothing.
Mode 5: OPEN / Release Motor - In this mode, the H-Bridge is disable and will allow free movement of the attached motor.
Changing Parameters and Settings:
When the mySunTracker is configured in Programming Mode, you can change the following operating parameters and there associated settings.
Parameters are selected by pressing the S1 push-button for 1 sec. Each time a new parameter is selected the Sensor 1 LED will blink the newly selected Parameter number of times.
Once a parameter is selected, pressing the S2 push-button for 1 sec will allow you to cycle thru the available settings for that parameter. Changing a setting will cause the Sensor 2 LED to blink the new setting value number of times. The settings for each parameter are stored in non-volatile memory and will be used each time the mySunTracker is powered up until they are changed again.
Parameter 1 -- Power Up Mode : RUN, PROGRAM, MANUAL, PARK, OPEN/RLS
Parameter 2 -- Motor On Pulse Duration : 0.2s, 0.4s, 0.6s, 0.8s, 1.0s
Parameter 3 -- Sensor Sensitivity : Minimum, Low, Medium, High, Maximum
Parameter 4 -- Tracking Update Rate : 15sec, 30sec, 45sec, 1min, 1min15sec
Parameter 5 -- Parking Direction : East, West, Off
Parameter 6 -- INPUT1 / INPUT2 Function : A, B, C (See below)
-- IN1 / IN2
A. Manual Motor Control -- Go East / Go West
B. Force Parking -- Park East / Park West
C. Maintenance Overrides -- Motor Brake/ Motor Open
Factory Default Programmable Settings are shown underlined. All parameters are stored in non-volatile memory and reload automatically at start-up.
First, before installing the mySunTracker, verify the powering system for the motor you have is sufficient to move the motor in both directions and that it does this without making the power supply voltage sag below 10VDC. Power supply voltages that sag too low when put under load can damage the H-Bridge Output FETS by forcing them to operate in a linear mode. This causes overheating of the FETs and eventually failure. The mySunTracker has a low voltage detect feature that will disable the H-Bridge output when the power supply drops below 10VDC.
Second, verify you have limit switches on the motor that will disconnect motor power when they have traveled to the East and West extremes of movement desired. Without limit switches, it is very likely you will damage your tracker, solar panels or both. Always test the limit switch operation and set the operating points without any panels on the tracker to avoid damaging solar panels. Also verify once you have installed the panels that the mechanical tolerances still are met and the panels won't get bumped at the limit stops.
Before attaching power to the mySunTracker carefully verify the polarity of the power connections to the unit. It is possible to damage the unit by connecting the power up backwards!! Always have the power turned off before connecting power to the unit!! Do not have the motor connected to the unit when first installing power.
Configure the mySunTracker settings before connecting the motor to the unit. Once configured, there is no need to reconfigure the mySunTracker after power interruption as the parameters and settings are stored in non-volatile memory.
Do not apply power directly to the motor connector or leads when they are connected to the mySunTracker board. This will destroy the driver transistors and incur a repair fee!! YOU MUST disconnect the motor wires from the mySunTracker motor connectors if you want to test your motors by connecting them directly to the power supply.
If you do damage the boards from mishandling, send the mySunTracker back in a padded mailer. We will fix the board and ship it back to you. There is a repair fee and return shipping due in this case. Failures due to normal wear and tear during operation are covered under warranty for 1 year.
If the mySunTracker moves the panels the wrong way during adjustment, reverse the motor connections.
The mySunTracker must be housed in a waterproof clear enclosure. The LEDs on the unit need to point toward the sun to work properly and have an unobstructed view of the sun. Shadows that block the LEDs view of the sun will have an affect on tracking and should be avoided.
If you are using the external inputs for manual control or manual parking, they must be connected to a dry contact closure (a simple switch is best). These inputs are not available for connection to digital logic or any signals with voltage on them from external sources.
If you have any questions about configuration or operation of the unit, please email email@example.com and I will be happy to help solve your install problem or technical question.
Input Voltage (12V version) : 10.0VDC - 19.0VDC
Input Voltage (24V version) : 15.0VDC - 30VDC
Input Current (Motor Idle) : 10mA nominal, 35mA max
H-Bridge Motor Current : 8 Amp, 30VDC max, pulsed duty
Operating Temperature : -25C - +60C Ambient
IN1, IN2 Programmable Inputs : DRY contact closure only
Here is the design schematic and PIC program for the processor.
Assembler Program Link for PIC16F676:
Pricing and Availability: (Not for Sale Anymore)
$65 for 12V version, fully assembled and tested unit
$65 for 24V version, fully assembled and tested unit
Fully Assembled Units come with a 1 year warranty.
The mydtcstore and its affiliates assumes no responsibility for damages caused by the use or misuse of our products. Use at your own risk.
Contact for more info -- mailto:firstname.lastname@example.org