Hexapod wanna be noob questions

Lynxmotion Legged Robots
1

Hi,

After viewing this & a few other forums I would like to make a hexapod so, I have a few questions if you dont mind.

  1. I am thinking of using the Lynxmotion SSC-32 controlled using an Arduino. Is this a good start?

  2. Which servos do you recommend?

  3. I would like it to be able to carry its own power supply (prefferable rechargable) what batteries and regulators would you suggest?

I will be printing my own chassis & legsto start with.

Thanks for any help

Nic

2

Hi, i always like custom projects. :smiley:
1) I am thinking of using the Lynxmotion SSC-32 controlled using an Arduino. Is this a good start?
simple answer is yes. well that would work but you might also want to look at what other set ups are using.
The cosmetics of your hexapod can vary dramatically but if you do keep to the same kind of controls then following the tutorials can be a great help. especially for a newbie?
you will notice that the same tutorials can be used for multiple set-ups…
lynxmotion.com/driver.aspx?Topic=assem04

2) Which servos do you recommend?
with your robot being 3D printed im expecting it will be quite light. but it will depend on the overall design.
most hexapods use the HS645MG servos but it really depends on how yours will be. here you will see most of these hexapods use the 645’s but some also use the 475’s or 485’s. its always worth looking to see if your design fits the same kind of design idea/weight etc of these:
lynxmotion.com/c-3-hexapods.aspx

3) I would like it to be able to carry its own power supply (prefferable rechargable) what batteries and regulators would you suggest?
again his will depend on your design and what you plan to add to it, etc.
most applications will use rechargable batterys and so really its up to you if on the type of supply you need??
Lipo, Ni-MH etc.

but i would recommend making sure you can supply the right amount of current… some thing about the 2200-2800mAh battery pack is perfect for small robots.

3

I am also a new hobbyist and I would like to getaway with the BotDuino Board, can I simply use any Arduino (i.e, Uno, Mega2560) for my controller? Which pins will be used for the PS2 communication?

Thanks
Chris

4

Yes, you can use another Arduino-compatible microcontroller instead of the BotBoarduino, however note that you may not have all the servo headers that are included on the BotBoarduino.

For the PS2 communication, you can generally use any 4 digital I/O pins however some digital I/O pins have special properties that make them incompatible. Some trial-and-error testing will be required to confirm if any non-standard pins would work. The BotBoarduino uses pins 6-7-8-9 for the PS2 controller.

5

Thanks Jeff, does 6-7-8-9 PCB header pins means its connected directly to the Atmel chip 6-7-8-9 pins? Thanks

6

Not exactly: pins 6-7-8-9 correspond to digital I/Os 6-7-8-9 in the Arduino code, but actually corresponds to PD6-PD7-PB0-PB1 (pins 12-13-14-15) of the ATmega328 chip.

You can find the schematic of the BotBoarduino here:

7

Noe: the Botboarduino is setup the same as a standard Arduino Duemilanove with an Atmega328. So any documentation you see online about this Arduino (pin numbers, what pins support PWM…) is exactly transferable to the Botboarduino.

The main difference with the Lynxmotion board, is the form factor was setup to work with their robots, plus there are 3 pin servo header pins for almost all of the IO pins. With these pins there is a power buss that allows you to choose Servo power or +5v to each group of 4 pins… Also there is some additional capabilities on this board, such as a buzzer, some leds and switches, which are on some fixed pins 5-9. However if this should cause your problems, such as a shield you wish to use these IO pins, you can remove jumpers on the board that enable these functions.

As for PS2, you can use any IO pins, but what makes 6-9 different is that we included an external Pullup resistor on what would be the data line. However in many cases you can use other pins as the Atmel328 chip has internal weak pull up resistors that you can turn on each of the pins. This is often sufficient, but sometimes is not.

Hope that helps
Kurt