@Gero I came with another video. I temporarily detached the RPi from the NyBoard and connected usb serial to check via serial monitor. Everything works fine until my Bittle falls down. When it is turned over (or every time it needs recovery), it spams and stops all motions including getting distance values from the sensor (as you can see from the serial monitor in the end of the video).

@Gero Yeah, I checked that. So it must work fine..... This is the video shows how my Bittle operates when I run the python code on RPi.

Thank you so much😭. I was not aware of that. I checked that sending commands works properly. Then, I put on the RPi and run your code of avoiding obstacles (https://www.petoi.com/forum/software/make-nybble-run-around-at-home-and-avoid-obstacles). It generally works fine, but when my Bittle is turned over, it spams and does not recover. I suppose the protothreading includes supervision of the recovery action (using gyro sensor). Isn't it? ++ I found that the recovery problem occurs even if I do not run the code on RPi.

@Gero Sure! #define ULTRA_SOUND #define SIG 8 #define LONGEST_DISTANCE 200 //cm; this sets the max delay for the ultrasound float ultraDistance; #include "Ultrasonic.h" Ultrasonic ultrasonic(8); void ultraSetup(){ pinMode(SIG, OUTPUT); pinMode(SIG, INPUT); Serial.begin(9600); } pt ptUltra; int ultraThread(struct pt* pt) { PT_BEGIN(pt); // Loop forever for(;;) { long RangeInCentimeters; RangeInCentimeters = ultrasonic.MeasureInCentimeters(); // two measurements should keep an interval Serial.println(RangeInCentimeters); //0~400cm delay(500); // Calculating the distance ultraDistance = RangeInCentimeters; } PT_END(pt); } void setup() { PT_INIT(&ptUltra); PT_INIT(&ptBodyMotion); pinMode(BUZZER, OUTPUT); ultraSetup(); ... I only changed these parts of your test code. I did not touch any of the other codes (including the body motion thread).

@Gero Yes, the remote control works but I temporarily used usb serial to check (via serial monitor) whether the sensor works.

@Gero I lengthened the sleeping time to 500. Now it does print out the distance more slowly but still does not react to the serial commands. When I type in any words in the serial monitor, the words are not even recorded on the serial monitor. 😿

@Gero Hi, thank you for your reply. I have solved the problem by referring to the source code and library that Grove Ultrasonic Distance Sensor provides. Now it successfully prints the distance in the serial monitor. I used Gero's testing-version code(https://github.com/ger01d/OpenCat/tree/ger01d-testing) and modified it a bit to fit Grove sensor instead of HC-SR04. However, I encountered another problem. I cannot send commands (e.g. kwkF, kbalance, etc.) via serial monitor. My Bittle keeps printing out the distances but it servos do not move at all even though I send serial commands. Is there something I might be missing?

The way I considered was: // ultrasound testings #define ULTRA_SOUND #define ULTRA_VCC +5V #define SIG 8 #define LONGEST_DISTANCE 200 // 200 cm = 2 meters (for OpenCat.h) and then change the variables Echo and Trigger to SIG in OpenCat.ino. Do you think this will make my Bittle success implementing this project?

@D_C_E @Rongzhong Li @Gero Hi, thank you for your posts and comments. I am currently working on the same project. I followed the same as @D_C_E but cannot see my ultrasonic sensor working. The thing is, I am doing it with Bittle instead of Nybble and my ultrasonic sensor is Grove Distance Ultrasonic sensor(not HC-SR04). The pin connection is currently GND > GND VCC > +5V NC > D9 SIG > D8 After searching, I noticed the difference of pins between two sensors as below. How should I rectify the OpenCat code that @Gero shared?

I have solved the problem! I just flipped the RPi and used NyBoard's 2x5 socket for Pi. Thank you for your reply anyway ;D

I completed the setting, following all the instructions in the post(I even installed the identical, past version of Arduino IDE - 1.8.8). But when I turn on the battery connected to the NyBoard, RPi does not seem to be turned on. Besides, there is no beeping sound(as a signal of checking its battery) that NyBoard used to make.

@Rongzhong Li Thanks for your fast reply! So you mean the connection of GPIO and DTR pin is enough, for the change in hardware, right?

Hi, Thank you for your post. As for the change in the hardware, along with the pin connection, may I ask which battery did you use for the RPi?

@Rongzhong Li Hello, I am back with a video. Gladly, 'push up' worked well after calibrating the robot once again. However, performing 'pee' is still not stable enough. Plus, a little spasm started to appear at the end of the movement. 😭

@Rongzhong Li I agree. As the bluetooth connection was not stable (I am a Mac user), I set up the wifi connection previously and it worked appropriately with all actions except 'pee' and 'push up' (problem of losing balance). So, I am planning to try those two actions again with wifi module after charging. I wish the re-calibration helps.

@Rongzhong Li Thanks for your super fast reply! I calibrated my Bittle once again with OpenCat.ino. It seems to perform 'pee' and 'push up' properly with usb serial. As I am charging it now, I will soon let you know whether it also works well with wifi module. Hope there would be no need to modify any constant:)

I tried to modify a constant of 'pee[]' in order to reduce the lifting degree of the right-back leg. I also confirmed the explanation about the code and indexes of motors in the 8th section of 'Petoi Bittle Manuals'. Think I must be missing something..

@Rongzhong Li Is there any difference between the calibration during openCat.ino and the calibration during writeInstinct.ino? I have now removed the rubber toe.

This is the picture of the robot. It does not seems to be wrongly assembled or calibrated as I carefully followed the tutorial several times. Plus, it did operate well before I modified the constants in InstinctBittle.h file. What would be the problem?