Can someone please let me know what are the differences between the servo drivers listed here?
I’m trying to understand if these work standalone or I need another controller for them.
I’m trying to control 4-5 servos with bluetooth.
So basic question: Do I need a microcontroller + driver to controller servos?
or Are the servo controllers listed below sufficient? or are these controllers actually drivers and will work with the microcontroller ? any insights would be appreciated.
Aha, that clears up some confusion right there. So basically all you need is a PWM output + extra power to drive the servos?
Ok, ROMEO is not available, what would you suggest as an alternate that can take LCD, bluetooth and control 6 servos?
So if servo’s plug in directly to the IO shield and if they are high power, like taking 1-2A, is that supported? or how should those servos be supplied?
All of the above need external input from a computer or microcontroller
]Flyduino/:m]
Has an onboard microcontroller and can store programs; microcontroller not necessary
You really only need the Flyduino and a Bluetooth module in XBee format (there are several). You don’t really even need the Digilent Controller. The Droid SAS MuIn is another option.
It’s excellent value, but you may have some experiences where not everything “Arduino” works perfectly; you might have to do some reconfigurations (it’s not ATMel based after all).
You just need some IO ports. For the joystick, you’ll need analog pins (at least two) The servo needs a pin which can do timed 5V pulses, repeated every ~20ms.
You have access to 12 pins; use them as you wish. The other pins are not accessible, so connecting the joystick and LCD won’t be easy.
Consider the ROMEO: It’s already setup for 3-pin connectors, separate power for servos, easy access to all the I/O, shield compatible, includes buttons and much more. It’s based entirely on Arduino, just with extra I/O and extra functionality. You’d add an LCD shield and the DFRobot Bluetooth module - the rest is plug and play.
A “servo controller” is essentially a microcontroller with specific code installed. The ROMEO is a microcontroller and can therefore drive servos, but the code is not specific for servos (i.e. you can do a lot more). You would use the Arduino servo library to operate the servos using the ROMEO.
Not even - you just need an output that can produce a 5V timed output, repeated ever ~20ms; not necessary PWM. All digital pins and analog pins on the Arduino can be used to drive servos. Keep in mind that each I/O pin can only power a servo which is not under load (40mA each) so if you plan to use a servo under load, you need separate power.
The ROMEO seemed perfect, so you might need a combination of alternatives such as: RB-Dfr-71 (I/O shield which has inputs for servos and also an XBee header). This unfortunately needs to be the last shield, so you cannot add an LCD shield on top - you would need to connect one separately.
Another option is to use the MEGA and the MEGA I/O expansion (RB-Dfr-137 and RB-Dfr-09). This is overkill, but includes the servo headers, the XBee slots and you can easily add the LCD shield.
Yes, and the I/O shield would make connections easier. The LCD you selected is inexpensive, but needs lots of I/O (fortunately the MEGA has more than enough).
There is no specific cable - you might try something like the 300mm F/F 40 pin jumper cable. You will also need headers.
The servos would plug directly into the I/O shield.
The first BT module is a shield and is easy to connect to the MEGA. The second is in XBee format and cannot connect directly to the MEGA - you need an XBee shield (or other shield with XBee headers). The third uses a footprint custom to DFRobot, so you’ll need a shield with that footprint.
You would use external power (there is a screw terminal onboard and you need to remove a jumper).
Most people find that a Serial LCD is easier to use than a parallel LCD.
RB-Dfr-177 is just parallel (no serial interface). The download file includes both the parallel and serial libraries and is not specific to any product. Note that the MEGA has enough IO pins to easily use a parallel PCD. The second one, RB-See-209, is significantly smaller than the first and is an OLED display. RB-Plx-151 is sort of the standard green, serial LCD. Serial costs more than Parallel since it uses far fewer pins and normally requires additional circuitry.
RB-See-209 is I2C (four specific pins required). Serial is two (Tx, Rx) or even one pin (Tx / Rx). In either case, the MEGA can be connected to any of them.
