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Upload Sketch for NyBoard
OpenCat software works on both Nybble and Bittle, controlled by NyBoard based on ATmega328P. More detailed documentation can be found at the NyBoard V1_0 or NyBoard V1_1.
Note: the version number is here
The I2C switch changes the master of I2C devices (gyro/accelerometer, servo driver, external EEPROM). On default “Arduino”, NyBoard uses the onboard ATmega328P as the master chip; On “RPi”, NyBoard uses external chips connected through the I2C ports (SDA, SCL) as the master chip.
Notes：
- Sometimes if you cannot go through the bootup stage, such as repetitively printing "IMU" and restarting, maybe you have accidentally dialed the switch to the "RPi" side.
- Before uploading the firmware, please make sure not to connect any I2C device to the I2C interface of the mainboard, otherwise, the firmware upload will fail. The location of the I2C interface is as shown below (in the red box):
The setup process for Nybble is almost the same, except that you need to change the model definition to
#define NYBBLE. Make sure you read through the following detailed steps. You will need the newest Arduino IDE to set up the environment. Older versions tend to compile larger hex files that may exceed the memory limit.
With NyBoard V1_*, you can simply choose Arduino Uno.
Only if the bootloader of NyBoard collapsed, which is very unlikely to happen
Every NyBoard has to go through functionality checks before shipping, so they should already have a compatible bootloader installed. However, in rare cases, the bootloader may collapse then you won't be able to upload sketches through Arduino IDE.
Well, it's not always the bootloader if you cannot upload your sketch:
- Sometimes your USB board will detect a large current draw from a device and deactivate the whole USB service. You will need to restart your USB service, or even reboot your computers;
- You need to install the driver for the FTDI USB 2.0 to the UART uploader;
- You haven't selected the correct port;
- Bad contacts;
- Bad luck. Tomorrow is another day!
If you really decide to re-burn the bootloader:
This step does not require the NyBoard to be mounted on the robot.
On Mac, the Bluetooth may lose connection after several uploads. In that case, delete the connection and reconnect to resume the functionality.
The Bluetooth dongle is not included in the kit sold by Seeed Studio or its partners. Please write to [email protected] for more information.
We keep updating the codes as an open-source project. You can star and follow our GitHub repository to get the newest features and bug fixes. You can also share your codes with worldwide OpenCat users.
- Download a fresh OpenCat repository from GitHub: https://github.com/PetoiCamp/OpenCat. It’s better if you utilize GitHub’s version control feature. Otherwise, make sure you download the WHOLE OpenCat FOLDER every time. All the codes have to be the same version to work together.
- If you download the Zip file of the codes, you will get an OpenCat-main folder after unzipping. Rename it to OpenCat before opening the OpenCat.ino, so that the two names match.
Arduino requires the .ino file to be put in a folder with the same name. You must rename the OpenCat-main folder as OpenCat (i.e. delete the -main suffix). Otherwise, Arduino will create another OpenCat folder and move OpenCat.ino into it. It will break the path dependency of related files.
No matter where you save the folder, the file structure should be:
- There are several testX.ino codes in ModuleTests folder. You can upload them to test certain modules separately. Open any testX.ino sketch with prefix “test”. (I recommend using testBuzzer.ino as your first test sketch)
- Open up the serial monitor and set up the baud rate. With NyBoard V1_*, choose the board as Arduino Uno and later set the baud rate to 115200 in both the code and the serial monitor.
- Compile the code. There should be no error messages. Upload the sketch to your board and you should see Tx and Rx LEDs blink rapidly. Once they stop blinking, messages should appear on the serial monitor.
To configure the board, please follow these steps:
Open the file OpenCat.ino and select your robot and board version. For example:
#define BITTLE //Petoi 9 DOF robot dog: 1x on head + 8x on leg
//#define NYBBLE //Petoi 11 DOF robot cat: 2x on head + 1x on tail + 8x on leg
//#define NyBoard_V0_1
//#define NyBoard_V0_2
#define NyBoard_V1_0
//#define NyBoard_V1_1
The symbol // deactivates the line of code and turns them into comments. Make sure you have only one line of the parallel options activated.
Comment out
#define MAIN_SKETCH so that it will turn the code to the board configuration mode. Upload and follow the serial prompts to proceed.// #define MAIN_SKETCH
If you activate
#define AUTO_INIT, the program will automatically set up without prompts. It will not reset joint offsets but calibrate the IMU. It's just a convenient option for our production line. 
Press the upload button.
You can find the button either under Tools, or at the top-right corner of the IDE.
Set the serial monitor as No line ending and 115200 baud rate.
The serial prompts:
Reset joint offsets? (Y/n):
Input ‘Y’ and hit enter, if you want to reset all the joint offsets to 0.
The program will do the reset, then update the constants and instinctive skills in the static memory.
You must enter ‘Y’ or ‘n’ to pass this step. Otherwise, the following parameters, including the skill data, will not be updated on the board.
The serial prompts:
Calibrate the IMU? (Y/n):
Input ‘Y’ and hit enter, if you have never calibrated the IMU or want to redo calibration.
Put the robot flat on the table and don't touch it. The robot will long beep six times to give you enough time. Then it will read hundreds of sensor data and save the offsets. It will beep when the calibration finishes.
When the serial monitor prints "Ready!", you can close the serial monitor to do the next step.
If you don't want to calibrate PCA9685(the servo driver), Step 9 can be skipped. The do Step 10 Upload the major functionalities sketch, and calibrate the joint servos if you have never calibrated the joints.
There's an optional step to calibrate the servo driver after the IMU calibration.
Optional: Connect PWM 3 -> Grove pin A3 to calibrate PCA9685
If later you find one of the servos stops working but can resume working after re-powering the servo, it's probably due to an inaccurate PWM driver signal. You must redo the previous uploading, and this step CANNOT be skipped.
This calibration makes the servo controller (PCA9685 chip)'s angle signal more precise. Use a short jumper wire to connect the PWM pin 3 (the signal pin of one of the servo pins) and Grove pin A3 and hold the wire steady.
The program will measure the pulse width of the signal and automatically calibrate the chip after getting three identical readings successive. It usually takes less than 2 seconds. The board will beep three times to indicate the calibration is done. The calibration offset will be saved to the board for the next time of bootup. The process should be done at least once, and we have calibrated every board after October 2022. But you can still do it by yourself, just in case.
The servo has a backdoor signal to modify its parameters, defined by the manufacturer. The PWM signal is 2700us with a tolerance window (2650 to 2750 us). The PCA9685's internal crystal has a frequency between 23MHz and 27MHz. The standard Adafruit servo library just set it to 25MHz if not calibrated. The regular servo PWM signal ranges between 500 to 2500 us. The error (27-25)/25 = 8% usually can be tolerated by the system. But when the joint signal falls in the range of 2700us, the servo will enter the configuration mode. Only powering off will break it out of the loop.
The optional step can be a quick fix. It utilizes the input pin of the main chip, which has an accurate external crystal clock, to measure the signal from PCA9685. It compares the measured pulse width and expected value, calculates a calibrating factor, and stores it in the chip. The process can be less than 1 second or several seconds. As long as it's done once, you don't need to do it again unless the temperature changes a lot. Calibrating the signal can also make the movements more precise if you are professionals who need to conduct motion-related research.
The calibration can be applied to all the PCA9685-based servo drivers that omit an external crystal. To recalibrate, just run the first round of the program again and connect the two pins after the IMU calibration. The calibration value can be seen in Arduino's serial monitor and should be pretty consistent.
Uncomment
#define MAIN_SKETCH to make it active. This time the code becomes the normal program for the major functionalities. Then upload the code.#define MAIN_SKETCH
Open the serial monitor. When the serial monitor prints "Ready!", the robot is ready to take your next instructions.
The default code runs the standard mode. If you have some extensible modules, you may uncomment the macro definition of a specific module. It will disable the Gyro code to save some programming space and activate the demo of the module.
The behavior of the official modules is defined in separate header files in OpenCat/src/. You can find them in OpenCat/src/io.h -> readSignal(). The behavior of OTHER_MODULES is defined in OpenCat/OpenCat.ino -> otherModule(). You can study the example code to write your own functions.
In certain cases, you may want to modify the "joint - pin" mapping of the robot. You can modify it in OpenCat/src/OpenCat.h. Make sure you are modifying the code block corresponding to the board version at the beginning of OpenCat.ino. After the modification, remember to save the changes and redo the uploading process from step 2.
