I am struggling with external eeprom. writeinstinct seems to be correctly uploarded. However servos move inconsistently every typing of "c". So, I cheked eeprom data via serial monitor. data looks exactly same as instinct nybble except negative value. every negative value is converted to positive like as -45 to 211 (256-45 ?) Is this normal or cause of inconsistent servos behavior? Please help.

I am uploaded writeinstinkt ino to the arduino nano. When I try to calibration, servo move according to the typing like (c0, 10 ),however even if type (s) correction value is not saved. Furthermore when I uploaded main sketch (opencat ino) servos respond only typing (c) and (d) via serial monitor. What did I mistake? ps #define I2C eeprom is uncomnented.

I am sorry to ask an old and common issue. I built a control board with arduino nano +PCA9685Servodriver just like as old Opencat schematic. Writeinstinct was successfully uploaded and type "c" in the serial monitor window. Servo(MG90s) looked like responded with "C" command and moved to the calibration pos. However new pos. is different from neutral position that I set using servo checker prior to the calibration. I also checked signal length of every output channel of PCA9685 using oscilloscope. result are following. If calibration state set every servo to middle position of working angle, signal should be around 1.5(x1/1000sec) as long as using the servo for RC. I am wondering whether my understanding for the calibration state is simply wrong or something wrong in the hardware or configuration of software. Your kind advise or comment are very much appreciated ch0 2.0 (x1/1000sec)　※value is not so accurate but looks "min" or "max" apparently not "middle" ch1 0.9 ch2 2.2 ch3 0.8 ch8 2.2 ch9 1.9 ch10 2.2 ch11 2.2 ch12 1.7 ch13 0.8 ch14 1.0 ch15 2.2