Hi Makeblock community,
I have recently bought a MS-12A and tried to control it via using Arduino Micro and ESP32 but still no success…
While troubleshooting what is wrong with this smart/digital servo, i discovered that 3.3V is coming from RX and TX pins of MS-12A smart servo while these pins are floating (not connected!).
I have supplied 5V to VCC of servo and still may have Hardware issue on RX/TX pins.
I have supplied 7.4V to VCC of servo and still same behavior exist on RX & TX pins…
Regarding to the leaflet (User Guide) of servo which is provided within the carton box of MS-12A, connection and pinout diagrams indicating that Arduino UNO’s (Which ihas 5V Vcc) RT/TX pins can be directly connected to RX/TX pins of MS-12A. Please correct me if i am wrong: Regarding to the this User Guide Connection Diagram, RX and TX pins should be 5V tolerant!
But why 3.3V is coming from RX and TX pins of serve while these pins floating (not connected)?
Is this behavior normal? I did not supply more than 7.4V to the VCC of servo.
I could not find any information about Absolute Maximum Ratings of VCC, RX and TX pins of this servo and what is the Logic Level (3.3V/5V) of RX/TX pins to work it properly?
When i check the schematics of AURIGO BOARDs SMart Servo Connection part i saw that there are two 51R resistor connected serially to RX and TX pins of the ATMEGA2560 MCU so is it necessary to run this servo on the other Arduino models?
And last question: MS-12A RX TX pins have Open Collector Output or not? Do we need to use Pull-up or Pull-down resistors to work RX/TX pins properly? Do you have only the schematics part of RX & TX pins to MCU of servo for better understanding how it is working ?
Thanks in advance…