We prepare a cheap robot vacuum cleaner
Good day. 
Today we will study the giblets and the scheme of the budgetrobot Agoten ECA MINI .
Given the primitive algorithm, it can be called a robot quite arbitrarily.
A lot of text, pictures and a survey for a snack.
When buying, there were no super-views, although I was pleasantly surprised - it works and even collects dust, maintaining cleanliness, extending the intervals between the usual “manual” cleaning.
Since this model is the youngest (bought in a network store for the equivalent of $ 100), we will not discuss the functionality of this product “out of the box” but look at the scope for handwriting and upgrades.
I see this device as a ready-made platform for a DIY robot vacuum cleaner.
The first candidate for an upgrade, of course, is the brain.
The power part for the beginning can be left available, and as a controller to use something from the Arduino clan.
There should be no problems with implantation into the current scheme, since In the original version, an EM78P153K microcontroller with 5V power supply in a 14 pin package (minus 2 power leads) is used, for a total of 12 leads to communicate with the circuit.
To plan the implantation of a new one, it’s necessary to begin with the idea of ​​what executive mechanisms and “sense organs” this “animal” has.
In this model of the vacuum cleaner there is no optical sensor on the suction hole (IR LED + photodiode) and the corresponding part of the circuit. Although the places in the case and wiring on the board are present, so if you want you can add.
The scheme is copied from the board, so inaccuracies are possible.
Unnamed transistors are something small SOT23. Q1, Q9, Q10 with Chinese Y1 marking - maybe SS8050, the rest with CR marking - maybe 2SC945. Although to understand the logic of the scheme, this is not particularly necessary. Unnamed diodes most likely 1N4148 in SMD performance, also their type is not particularly important.
Binding microcontroller no. Absolutely not. So it is not on the diagram, there is a reference to the conclusions. It is corny powered by + 5V and the rest of the legs diverge according to the scheme.
Q1, Q2, Q15 This is a battery charging key. I note that here it is charged just in time with the maximum current limit through a 5-watt R73 resistor. There is no control, so looking at the scheme, I charge my battery with an IMAX clone with the end of the charge in ΔV, it will live longer.
The 8.25V stabilizer on the MS34063 is depicted as a block, since the microcircuit is turned on according to a typical scheme. Resistor Rsc (see datasheet) 0.22 ohm. Those. there is a current limit, not only to protect the chip itself, for something slightly lower.
From it feed wheel modules and drives of lateral brushes.
')
At the LM393 dual comparator, monitoring of the drawdown of the power supply of the wheel modules and side brushes (in case of jamming with foreign objects or mechanical malfunctions) and the discharge of the battery is assembled. These two conditions for the controller are one event.
The suction fan is turned on with the side brush drives by the transistor Q24. In this case, the fan is powered almost directly (minus the voltage drop across the diode D16 and the open transistor) from the battery. Overclocking, however :-) The side brushes on the contrary are powered by a low voltage of 8.25V minus a drop on 3 diodes and an open transistor.
Optocouplers JK1 and JK2 - slot-hole transistor. JK2 is normally darkened (the lid is closed - the transistor is closed) and JK1 is normally illuminated (the bumper has not rested anywhere - the transistor is open)
On the transistor Q25 assembled key switching power supply of the LEDs of the optocouplers and the entire node of the drop sensors. In the presence of 19V from the charger it is closed, in all other cases it is open.
On the transistor Q8 assembled control circuit availability of 19V from the charger. The signal goes to 7 pin. microcontroller. A phototransmitter of the optocoupler of the lid is also connected there. Those. connected charger and open cover for the controller one event. How does the controller distinguish when the cover is open, and when the charger is connected? By bumper sensor. When the charging phototransistor is connected, it will be shaded due to the power off of the LED (Q25 key). So if you open the lid and press the bumper when the charging vacuum cleaner is off, it will think that it is charging, it should also stand on the surface so that the drop sensors do not work (they are disabled when the charger is connected). This is the price paid for the ultimate simplification of the scheme. The charge mode is indicated by a flashing green LED (in the lower left corner of the circuit). In order not to mislead (or perhaps not frighten) the user with a vacuum cleaner that shows charging without a charger, the designers simply do not allow the LED to blink due to the Q9 transistor, although from the first output of the microcontroller to the LED there is a meander. Crutches
Nothing remarkable stands out.
It works simply - on both inputs logical 0 - we stand
We give 1 to one of the entrances - we go either forward or backward.
We give two 1-tsy sadim + VCC Motor to the ground. There is no protection "from the fool", so either two are 0 or one each.
Schematically, they represent an optical pair of LEDs — a photodiode directed to the surface, while the photodiode is structurally more distant from the surface and can be partially covered by an adjustable shutter to select the pickup height (there is a photo at the beginning of the article). To decouple from the level of illumination in the room, the LED is modulated with a certain frequency.
The scheme is approximate, for understanding the principle of operation. The selected part is individual for each channel, the generator is on the first and the comparator on the last operating station is common to all.
Show their activity logical 1 to the diode D2
The triggering of the drop sensors and the stop of the bumper into the obstacle for the microcontroller is one event.
In the case of active 0 will be marked.
1 Green LED
2. The bumper rested against an obstacle or any drop sensor worked - active 0
3. Bazzer (squeaker)
4. + 5V
5. Drawdown of the power of the motors of brushes and wheels and the discharge of the battery.
6. Turn on suction fan and side brushes.
7. Charger connected or lid open - active 0
8. Left wheel
9. Left wheel
10. Turn on the charging key - active 0
11. GND
12. Right wheel
13. Right wheel
14. Red LED.
In my opinion, the main drawback of the current circuit is the combined trigger signals of the bumper and the drop sensors, so with the current algorithm, the vacuum cleaner encounters an obstacle while moving “straight” just turns 180 ° and travels away from it to another wall, and so several times along the same path . Therefore, it is very desirable to divide these signals, in order to more adequately respond to obstacles and the "ends of the earth".
It would also be nice to add intelligence to the charge circuit.
Now you can unsolder the native microcontroller, connect * uino, or whatever you like and invent your own algorithms, but this will be in the second part.
Everything stated in this article is purely my conclusions and impressions and expresses my opinion in this matter, but how many people are so many opinions.
Today we will study the giblets and the scheme of the budget
Given the primitive algorithm, it can be called a robot quite arbitrarily.
A lot of text, pictures and a survey for a snack.
When buying, there were no super-views, although I was pleasantly surprised - it works and even collects dust, maintaining cleanliness, extending the intervals between the usual “manual” cleaning.
Since this model is the youngest (bought in a network store for the equivalent of $ 100), we will not discuss the functionality of this product “out of the box” but look at the scope for handwriting and upgrades.
I see this device as a ready-made platform for a DIY robot vacuum cleaner.
The first candidate for an upgrade, of course, is the brain.
The power part for the beginning can be left available, and as a controller to use something from the Arduino clan.
There should be no problems with implantation into the current scheme, since In the original version, an EM78P153K microcontroller with 5V power supply in a 14 pin package (minus 2 power leads) is used, for a total of 12 leads to communicate with the circuit.
General view of the viscera
To plan the implantation of a new one, it’s necessary to begin with the idea of ​​what executive mechanisms and “sense organs” this “animal” has.
What does the manufacturer of this miracle offer us?
Charger 19V 600 mA
Ni-MH battery of 12 AA cells with a promised capacity of 800 mA-h
2 wheel modules with collector engines.
Internal organization
Planetary reductor
Engine
Internal organization
Planetary reductor
Engine
Centrifugal fan pulling air through the dust box.
12V 0.5A
2 drive side brushes.
3 IR sensors of protection from falling from steps.
Outside
Inside
Inside
Bumper with 1 collision sensor (conventional slit optocoupler).
Slit optopara presence of the top cover.
In this model of the vacuum cleaner there is no optical sensor on the suction hole (IR LED + photodiode) and the corresponding part of the circuit. Although the places in the case and wiring on the board are present, so if you want you can add.
Consider the electrical circuit
The scheme is copied from the board, so inaccuracies are possible.
Unnamed transistors are something small SOT23. Q1, Q9, Q10 with Chinese Y1 marking - maybe SS8050, the rest with CR marking - maybe 2SC945. Although to understand the logic of the scheme, this is not particularly necessary. Unnamed diodes most likely 1N4148 in SMD performance, also their type is not particularly important.
Binding microcontroller no. Absolutely not. So it is not on the diagram, there is a reference to the conclusions. It is corny powered by + 5V and the rest of the legs diverge according to the scheme.
Go through the main nodes
Q1, Q2, Q15 This is a battery charging key. I note that here it is charged just in time with the maximum current limit through a 5-watt R73 resistor. There is no control, so looking at the scheme, I charge my battery with an IMAX clone with the end of the charge in ΔV, it will live longer.
The 8.25V stabilizer on the MS34063 is depicted as a block, since the microcircuit is turned on according to a typical scheme. Resistor Rsc (see datasheet) 0.22 ohm. Those. there is a current limit, not only to protect the chip itself, for something slightly lower.
From it feed wheel modules and drives of lateral brushes.
')
At the LM393 dual comparator, monitoring of the drawdown of the power supply of the wheel modules and side brushes (in case of jamming with foreign objects or mechanical malfunctions) and the discharge of the battery is assembled. These two conditions for the controller are one event.
The suction fan is turned on with the side brush drives by the transistor Q24. In this case, the fan is powered almost directly (minus the voltage drop across the diode D16 and the open transistor) from the battery. Overclocking, however :-) The side brushes on the contrary are powered by a low voltage of 8.25V minus a drop on 3 diodes and an open transistor.
Optocouplers JK1 and JK2 - slot-hole transistor. JK2 is normally darkened (the lid is closed - the transistor is closed) and JK1 is normally illuminated (the bumper has not rested anywhere - the transistor is open)
On the transistor Q25 assembled key switching power supply of the LEDs of the optocouplers and the entire node of the drop sensors. In the presence of 19V from the charger it is closed, in all other cases it is open.
On the transistor Q8 assembled control circuit availability of 19V from the charger. The signal goes to 7 pin. microcontroller. A phototransmitter of the optocoupler of the lid is also connected there. Those. connected charger and open cover for the controller one event. How does the controller distinguish when the cover is open, and when the charger is connected? By bumper sensor. When the charging phototransistor is connected, it will be shaded due to the power off of the LED (Q25 key). So if you open the lid and press the bumper when the charging vacuum cleaner is off, it will think that it is charging, it should also stand on the surface so that the drop sensors do not work (they are disabled when the charger is connected). This is the price paid for the ultimate simplification of the scheme. The charge mode is indicated by a flashing green LED (in the lower left corner of the circuit). In order not to mislead (or perhaps not frighten) the user with a vacuum cleaner that shows charging without a charger, the designers simply do not allow the LED to blink due to the Q9 transistor, although from the first output of the microcontroller to the LED there is a meander. Crutches
Wheel Motor Drivers
Nothing remarkable stands out.
It works simply - on both inputs logical 0 - we stand
We give 1 to one of the entrances - we go either forward or backward.
We give two 1-tsy sadim + VCC Motor to the ground. There is no protection "from the fool", so either two are 0 or one each.
Drop Protection Sensors
Schematically, they represent an optical pair of LEDs — a photodiode directed to the surface, while the photodiode is structurally more distant from the surface and can be partially covered by an adjustable shutter to select the pickup height (there is a photo at the beginning of the article). To decouple from the level of illumination in the room, the LED is modulated with a certain frequency.
The scheme is approximate, for understanding the principle of operation. The selected part is individual for each channel, the generator is on the first and the comparator on the last operating station is common to all.
Show their activity logical 1 to the diode D2
The triggering of the drop sensors and the stop of the bumper into the obstacle for the microcontroller is one event.
"Summary" of the legs of the microcontroller
In the case of active 0 will be marked.
1 Green LED
2. The bumper rested against an obstacle or any drop sensor worked - active 0
3. Bazzer (squeaker)
4. + 5V
5. Drawdown of the power of the motors of brushes and wheels and the discharge of the battery.
6. Turn on suction fan and side brushes.
7. Charger connected or lid open - active 0
8. Left wheel
9. Left wheel
10. Turn on the charging key - active 0
11. GND
12. Right wheel
13. Right wheel
14. Red LED.
Total
In my opinion, the main drawback of the current circuit is the combined trigger signals of the bumper and the drop sensors, so with the current algorithm, the vacuum cleaner encounters an obstacle while moving “straight” just turns 180 ° and travels away from it to another wall, and so several times along the same path . Therefore, it is very desirable to divide these signals, in order to more adequately respond to obstacles and the "ends of the earth".
It would also be nice to add intelligence to the charge circuit.
Now you can unsolder the native microcontroller, connect * uino, or whatever you like and invent your own algorithms, but this will be in the second part.
Everything stated in this article is purely my conclusions and impressions and expresses my opinion in this matter, but how many people are so many opinions.
Source: https://habr.com/ru/post/375313/
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