i have 3 sg90
arduino uno
breadboard
jumper wires
mg995 servo motor
so i dont know what would be a good power source i tried using 2x 3.7 v lithum batteries and that doesnt work can someone help me out im building a simple robot with eyes please dont ask my to buy a buck down converter because a multimeter is too expensive in my country
so like tell me exactly what do i buy i need 5v for all I THINK
Your best bet would be a 5V wall wart or two of them, one for the UNO and one for the 3 servos.
Maybe you only want battery power? If true (you didn't say) then a NON adjustable buck is the solution. I would use at least 3 3.7V batteries though in series.
what do you mean one for the 3 servos? I dont understand sorry im new to robotics but I dont want better power because chatgpt said that 2x 3.7 batteries would damage the servos also what does using these batteries in series mean
From here: post #1.
Online datasheets refer it needs around 550 miliamps, so 550*=1650miliamps or 2.00 at 5 volt. You need atleast a 5v 2A amp supply.
From Net:
The MG995 servo needs 4.8V to 7.2V DC, with 5V-6V being typical, drawing significant current, especially when stalled (up to 1.5A or more), so it requires an external power supply, not the microcontroller's USB port, providing at least 2 Amps for smooth operation. It consumes around 10mA idle, 170-400mA moving, but peaks much higher under load, so a robust 5V/2A+ supply is key for its high torque (around 11 kg-cm at 6V).
Total requirememt: 5V/4A.
If using battery, then provide information about battery type, its cell voltage, and how long to operate. I will let you know about AH capacity.
You could use:
so 4 aa batteries will be good or will i need a buck conveter or will it be good without it like it will be able to power
arduino uno - pca9856 - 3x sg90 1 mg995 @jim-p
For a battery, is it sufficient to know only the terminal voltage, or do we also need to know its Ah capacity?
That would be you last choice if you can't do anything else because 4 AAs will not last very long and they are not rechargeable.
You need to learn a lot of basics before attempting a robot.
yes i know can u reccomend vidoes or the sources you learned i dont even know what to search up like do i searh up like i know basics of circuit and ohms law but like can you please tell me the source of where YOU learned the basics thanks
I learned the basics by attending High School classes for 1/2 a day each of 5 days a week for 4 years. That was followed by many years of on the job training. That was 1959-1963
oh makes sense
You have a big advantage though. With YouTube and other on-line resources you have access to a lot of knowledge. The hard part today is finding a properly organized approach. I have no ideas since I don't need that level anymore but I am currently involved with a local high school so may have some ideas soon. Good luck.
Some resources I have used are
DroneBot Workshop
The Swiss Guy Andreas Spiess
Ralph S Bacon
Rui Santos
Paul McWhorter
thanks as someone recently entering robotics this helped me out a lot
@robotmaker6000
1. You connect four 1k resistor in series. The total value is 4 k ohm.
2. You connect four 1k resistor in parallel. How much is the total value? It is only 0.25 k ohm. How?
3. You connect four 2200 uF capacitors in series. The total value is 2200/4 uF.
4. You connect four 2200 uF capacitors in parallel. The total value is 2200x4 uF.
5. Batteries are like capacitors.
If batteries are connected in series, the voltages of the cells add up, while the Ah (ampere-hour) capacity remains the same as that of a single cell.
If batteries are connected in parallel, the voltage remains equal to the voltage of one cell, while the Ah capacity becomes the sum of the individual cell capacities (four times for four identical cells).
what ?? what that mean im new to robotics sorry
Could be but to really know you need to do a little math. First find out the capacity of the battery. This is sometimes marked on the battery but not in this case so google is your friend. You will need to google capacity for Duracell AA Alkaline (manufacturer, size, chemistry). You will get back a range, use the lowest which in this case is 2,400mAh. If you only have batteries in series then divide the 2400mAh by the servos draw also in mAh (convert as needed, I assume you know the relationship between Amps, milliamps and microamps)
In this case 2400milliamp hours / 1650 milliamps. This is the worst case scenario where all 3 servos are operating at once in other words 100% duty cycle. The math yields 1.45 hours. Since you will unlikely be at 100% duty cycle, a more reasonable 25% duty cycle would yield almost 6 hrs and that is for all 3 so again a more reasonable estimate is 2 out of 3 so 9 hrs. Remember that is just for the servos, you still need to power the UNO. A pair of 18650's in series will work nicely.
