Sun tracking electronics controlled by AVR

- The settings:

You can see after switch on:

The calculated X and Y coordinates in degrees

In the bottom line, the first four digits are the year, followed by the current day of the year.
In the lower right corner you can see the exact time. (H, m, s).
To make it easier to enter the current date, here is a table: (in case of a leap year, after February 28, add 1)
It is worth printing and keeping it close to the circuit. J

There are four buttons available to navigate through the menu:

Moving left and right: UP, LE, ENTER, EXIT / HOME
By default, use the up / down keys to switch to another menu.
Press ENTER to change the data on the current screen.
Press ENTER again to move to the next data.
The set values are written to the EEPROM when the EXIT button is pressed, so the settings will be retained in case of a power failure (Only the year, current day, latitude, and engine settings are saved.)
Because the microprocessor's EEPROM content is finite (max.10000-100000 writing is a lifespan), so just daily
It is written for 1 time, guaranteeing a minimum of 27 years of faultless operation (10000 / 365,25 = 27,3785 years).
If the memory area with the number of the day had collapsed after 27 years, then the circuit would work, but in case of a power outage the number of the day should be reset too :).
At midnight, the new date will be saved. It follows from this limited write option that the exact time is not saved because, for example, Every 7 days, more than 10000 writing would be available in the EEprom area, so it would be within a few weeks to break the part of the memory and forget the exact time.
To exit the programming mode, press ESC / HOME.
If you press it again, the parabola will go to the HOME position (X = 0 degrees, Y = -90 degrees - that is to the south and toward the earth)

The propulsion of the tracking mechanism can be of two types:
DC motor or stepper motor
It is recommended to use the DC motor as it does not have a resting current on the stepper motor.
When the engine is switched off, the drive must be locked with a brake.

For DC motor control, 0.25 means that a change of state (no clock signal) comes from the decoder disk at 0.25 degrees.
This means that there is a mark (or optical aperture) of 0.5 degrees on the signal disk.
If you divide the encoder 360 into 360, it means that 360 transparent and 360 non-transparent parts will be alternating with it.
This 1-degree disc has a precision of 0.5 degree as it will have a 720 state change.
The main screen with the coordinates:

When using a stepping motor, you do not need a dialer, only the HOME sensor
(Semicircle-clearing of an opt-out gate, where the circle is transparent through 180 degrees)

Home Position Sensor Optical Disc

But here, too, you have to give 1 degree how many steps the parabola is doing (200 steps / degree base is set)
One Piece: If the engine does 200 steps in one revolution and turns 2 degrees in 1 degree of parabola then
Set 400 (This is why step / degree is the unit of measure).

The latitude should also be given, but this is basically set to Budapest (47.5 degrees).
The letter N signifies that we are in the northern latitude, that is, in the north of the globe.
If you set a negative value, the letter "S" appears, indicating the Southern Hemispheres,
(So the circuit can be used all over the world.)

For a stepping motor, you can change the stepping speed.
The smaller the number you enter, the less you wait between two steps. This can eliminate the loss of a move.
It is not recommended to go faster at 1 degree per second (This is especially true with DC motors for possible overshoot).
When using a DC motor, apply a motor with a recommended brake and build the parabola mirror in a balanced way
(So the load of the engines will be much smaller).
-The circuit:

Make sure that the supply voltage is well-filtered, uninterrupted, stable at 5V!

PCB plans in bmpFigyelem! Elavult verzió!

The software in .HEX(26,7kB) Figyelem! Elavult verzió!

Since they are made for the iron-based panel manufacturing technique, they are mirrored (the inscriptions have to be looked at).
The controller's mind is a TQFP enclosure ATMEGA32.
The electronics consumes only a few mAs so the power outage can be overcome for a long time.
When using a DC motor, if the motors are off the voltage, the electronics are on the encoder disks
You will know where the parabola stands, so that you can fit in the right position later.
In the case of a stepping motor it is not realized because there is no feedback at this time! (UPS is recommended).
If you press the HOME button, the position is reset to Home when passing
Again, the parabola will be in the right place.
The 1Hz external clock signal is provided by a cheaply-made Chinese alarm clock transformed electronics. (Since then, it is already software)
Since it runs from 1.5V in factory, there is a transistor in front of the microcontroller.
The 1.5Volt is produced with a 1k resistor and 3db diode (giving approximately 1.8V).
By default, the voltage on the alarm clock is changed by polarity, so it is disconnected with 2 diodes
The positive "half-period", and this goes to the 1Hz clock signal input.

The X> and X <inputs (PB1, PB2) are an optical detector. If the sun shows a deviation horizontally, every minute
The electronics are corrected for 1 second (eliminating possible fuzzy light).
The clock does not show the current time but the current solar time.
So there is no winter / summer time, but there is a ground clearance inaccuracy and clock counter error correction.
Correction is activated every second at 30th second. Pushbuttons from PB3 to PB6 are to be connected to the + 5V rail with 10k resistors. In addition, all inputs must be connected to + 5V by 10k.
(It uses no external clock code for the newer circuit and where possible internal pull-up resistors are activated in the microprocessor)
All the terminals are driven by a mandrel to disassemble or replace all the components of the circuit.

PD0 = Output 'X + / Step X (with DC Motor + Direction / Stepping Motor Clock)
PD1 = Output 'X- / Dir X (for DC motor - Defining / Direction of stepping motor direction)
PD2 = Output 'Y + / Step Y (DC Motor + Direction / Stepping Motor Clock Rate)
PD3 = Output 'Y- / Dir Y (For DC Motor - Define / Define Directional Motor Direction)
PD4 = Input 'X home position - resets the X coordinate when changing the state
PD5 = Input Y position - resets the X coordinate when changing the state
PD6 = Input 'X signal at DC motor This feedback is from the position. (Baseline 0.25 degrees / change of state)
PD7 = Input Y for a DC motor this is a feedback of the position. (Baseline 0.25 degrees / change of state)
PB0 = Input 'clock transducer
PB1 = Input '-X> Correction
PB2 = Input -X <correction
PB3 = Input 'button up
PB4 = Input 'button down
PB5 = Input '-Enter button
PB6 = Input '-HOME button
PB7 = Output 'Pump control
PA0 = Input Th1 Thermometer (Parabola Focus Heat Exchanger)
PA1 = Input Th2 temperature measurement (water storage temperature)

On the right, a standard HD44780 compliant 2X16 character display is connected.
The bottom P10k mark is a 10k potentiometer that adjusts the display contrast.
Since several people have indicated that they are unable to process the SMD processor, I have also made a conventional DIL-circuitry.

Of course, because of the panel-laying technique, the circuit is also reflected here!
-Because there were still some free terminals, the circuit was expanded with two thermometers and one relay,
Thus, it is already possible to control a circulating pump, or if it is boiling water, this will
Out of the sun. If it is too cold (<3 degrees), the pump will not start.
Thermometers are connected to inputs A0 and A1. A0 measures the temperature of the heat exchanger placed in the focal point,
A1 should be placed in the buffer tank. The Pump can be connected to the PB7 via a relay.
There were 2 10K resistors that produced the reference voltage (2.5V).
Accordingly, the output voltage of the voltage distributor generated by the thermometer and a resistor can not be higher!
And finally there is an implant drawing:
The red highlighted parts are + 5V, the blue is 0V.

The newer circuit design is in progress.
Warning Circuit has been completely redesigned since then! See description of the newer circuit (under construction)

Last update: 2009-05-16

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