RoboPanda Disassembled - A Look Inside This Friendly Robotic BearPosted by Nocturnal on Monday, 28 April 2008
This is the TV commercial for the RoboPanda. Despite the ad, and the safety features built in to the RoboPanda, I would not recommend letting your small child run around the house carrying one.
RoboPanda's rump contains a hatch, inside at the top is the socket for one of the RoboPanda's cartridges. On the lid is a carrier for the cartridge that is not currently in use, you can see RoboPanda's black cartridge mounted in it. Finally, the rear hatch also contains the third battery box (the other two are in his feet). Just visible on the right hand side inside the socket, where RoboPanda's cartridges are inserted, are the metal prongs of a small switch. This switch is connected to RoboPanda's power. No cartridge, no power.
Now enjoy the RoboPanda in store promotional video.
Inside RoboPanda's cartridges is a small circuit board. Hidden under that small epoxy blob on the circuit board is a 3.3v SPI 8 megabyte ROM, on which the RoboPanda's stories and actions are stored.
This panel is used to cover RoboPanda's shoulders, that bit of copper sheeting in the middle is one of RoboPanda's capacitive touch sensors. Each sensor has two wires running to it, but only one is actually connected to the sensor, the other is for shielding.
This video was apparently put together to showcase the features and functionality of the RoboPanda for CES 2007.
Inside the RoboPanda's rear shell you will find, the power / mode switch complete with reset button, below that, is the rectangular touch sensor. Underneath that is the board containing the socket for the cartridges, and finally at the very bottom is one of the battery compartments.
After removing RoboPanda's rear shell, the main circuit board becomes visible. Interestingly, the main board is not firmly attached to the torso as in other Wow Wee offerings. Instead, its somewhat loosely mounted with rubbed washers. I wonder if this is to make him more crash resistant.
Here we see the unpopulated programming connector on the RoboPanda's main board, that connects to the RoboPanda's CPU. This is most likely left over from the development cycle, and the CPU will probably be ROM based rather than FLASH based.
On the main board, on either side of the purple socket, are pads where initially a ball bearing tilt sensor was mounted (visible in the FCC filings). This sensor is now mounted underneath the neck.
Once the RoboPanda's main circuit board is removed, you can find the motor board slotted in to the body. No screws, it just slides in there. You can also see the three motors, the left and right motor, rotate the left and right should in and out. The middle motor, tilts RoboPanda's head up and down.
This is what the RoboPanda's motor board looks like when slid out of the body. Its pretty much just a series of H-bridges. Also visible on the left next to the motor is the accelerometer board.
The RoboPanda's accelerometer can detect acceleration along two axises, and indicate that as a voltage on the appropriate signal line. The datasheet for the chip is freely available, which means that should anyone want to repurpose the circuit, it shouldn't be to hard to figure out.
This is the inside of RoboPanda's chest shell, showing the speaker. You will also notice that although there are two touch sensors, the are linked together as one.
This is what is inside RoboPanda's stomach shell. The big copper circle is the touch sensor, at the top is a LED, below that is the RFID circuit. Not visible behind the RFID circuit is the RoboPanda's mic.
The RFID reader is actually fairly plain, most of the circuit is hidden underneath the metal shield. Without knowing more about the circuit, its impossible to say if this reader could be used or modified for another purpose, or work with tags other than the one in his furry friend. All I do know is that the operating frequency is 13.56 MHz.
Hidden behind RoboPanda's stomach shell is the touch sensor board, for the ten capacitive sensor in the RoboPanda. This board communicates via a standard serial connection, and again the datasheet for the chip is publicly available, so repurposing it should be fairly easy.
What I can't figure out is the intended purpose of the straps on the chest. At first I thought these straps were some form of flexible rack and pinion gear system for moving the arms, but a closer examination shows that they are just for spring loading the shoulder joints. The part I can't figure out is why the inward movement of the arms needs to be spring loaded.
Just visible inside the shoulder joint is the gearing for rotating the primary shoulder joint. The shoulder is interesting, unlike other Wow Wee bipeds, the shoulder rotates in two directions. With the RoboSapiens, the shoulder lifts the arms up and down, and there is a second wrist / elbow that rotates the hand. In this case, the primary joint rotates the arm in and out, and the secondary joint in the shoulder raises and lowers the arm. I suspect this change is to allow RoboPanda to hug things, rather than try to pick them up.
This is what RoboPanda's head looks like on the inside. This is pretty much the only place there is empty space. There are three motors inside RoboPanda's head, they control the left / right motion of the head as well as the motion of the ears and eyebrows. Like various other parts of RoboPanda's body, the head is not firmly attached to RoboPanda's skeletal structure. Instead it rides on a spring, and two screws with wide washers hold it firm against the neck.
This is what RoboPanda's face looks like from the inside. You can see the small head touch sensor, and the wiring for the sensor and LEDs in the face. Notice the metal can below the wires going to the LED in the left eye? Thats an IR Receiver, which is normal in something that has a remote, but weird for the remote-less RoboPanda. You may have also noticed the wires going to the nose, hidden inside is an IR LED.
This is what RoboPanda's head looks like without the shell or circuit board, doesn't look much like a face. The white plastic and metal bits on the side are the position sensors for the eyebrows and ears. The sensors are essentially a pair of limit switches. The ears are linked to the black plastic piece at the top, and the eyes link to the gray plastic slit on the right, with the springs on either side. As either of them moves, one of the small white cam rotates until it touches one of the two switches.
This is the circuit board from inside RoboPanda's head. Mostly its just a break out board for the wiring traveling up the inside of the neck, but it also has 3 h-bridges to control the motors in the head (head left / right, eyebrows up / down, ear back / forward).
This is the inside of RoboPanda's leg. Visible near the top is the pot used to determine leg position. Just visible on the left, is the touch sensor, and at the bottom is the battery compartment. Other than the screws hold two halves of the shell together, there are no screws holding the gearbox in place. The gearbox has tabs that go into foam lined sockets. I'm not sure if this is to allow the legs a certain amount of give and take, or if it is an attempt to muffle the noise / vibrations of the leg motors.
This shows the inside of the RoboPanda's hands. Visible are the touch sensors. Attached to the white plastic is the LED that lights up the hands. Finally, there is the motor that rotates the secondary shoulder joint.
For anyone who is thinking of trying this themselves, in order to really dismantle the head, you have to dismantle the neck, which is a serious pain to put back together again correctly. Do not dismantle the neck unless you REALLY have to.
Overall the RoboPanda is quite interesting, Wow Wee has packed a lot into what is mostly quite small spaces. The only place where there is really any free space is inside the head. In a way, the RoboPanda is more hi-tech than any other of their products, even the RS Media, with its capacitive touch sensors, RFID reader and 2 axis accelerometer.
I wonder if Wow Wee will be releasing additional cartridges for the RoboPanda, its obvious from the hardware that the RoboPanda is designed to allow for it. Future cartridge could take advantage of the RFID reader in new ways, with new games, and the IR gear in the head would allow it to interact with various things.
The coolest hack for the RoboPanda would obviously be to create a new cartridge for the RoboPanda, unfortunately for us, based off a little probing of the cartridge content, it looks like Wow Wee may have taken steps to protect their investment in the RoboPanda, by making it difficult for anyone to develop a third party cartridge.
Keep your eyes peeled, I'm going to be writing at least one more article about this little guy.