Question about the DFRobot RoMeo Arduino clone

Using Arduino Motors, Mechanics, Power and CNC
#1

I've been thinking of getting the DFRobot RoMeo Arduino clone to replace/augment my Uno R3, as it would allow me to experiment with motors without using shields, etc. It has a number of features that would allow skipping the traditional shield/breadboard (ground/5volt/signal for every pin using female cables, external power supply for both servos and motors, unlike the Adafruit motor shield it doesn't use all of the digital pins leaving only the analog pins, it has multiple i2c headers, and it has 7 buttons builtin).

I have a question: I see the power connector for the servos, but nowhere do I see mention of dedicated pins for the servo. Does this mean when supplying external power to the servo motor port that the voltage pin for all of the digital pins (D0-D13) now is powered by the external power supply (cool)?

Another question is the build quality. I have the DFRobot LCD shield, and after I bought it, I was seeing some sites say not to use pin 10 to control the screen's brightness. So, this doesn't give a warm and fuzzy feeling about their quality in other aspects.

#2

I have a question: I see the power connector for the servos, but nowhere do I see mention of dedicated pins for the servo.
Does this mean when supplying external power to the servo motor port that the voltage pin for all of the digital pins
(D0-D13) now is powered by the external power supply (cool)?

If the “Servo Power Jumper” is in place the Power pins for the digital pins are connected to +5v and you should probably NOT connect power to the “Servo Power Input” because it will clash with the +5V line . With the jumper out the Power pins are connected to the + side of Servo Power Input.

#3

johnwasser: If the "Servo Power Jumper" is in place the Power pins for the digital pins are connected to +5v and you should probably NOT connect power to the "Servo Power Input" because it will clash with the +5V line . With the jumper out the Power pins are connected to the + side of Servo Power Input.

Thanks. Yes, I imagine bad things will happen if apply power to the servo power pins if you don't have it jumpered correctly.

#4

HI:

The romeo servo terminal has auto switch feature which will automatically select power from USB/Power Jack or servo terminal. Look at the schematics, the servo power terminal will not power Atmega328 and won't damage your romeo board.

So, no worry. if you have anything wrong with power supply. We have tried everything possible to protect your investment.

BTW, the DFRobot LCD shield you mentioned is probably the old version which has been updated with the latest version that supports brightness adjustment.

And, if you buy our product from ebay, be careful of the fake version of DFRobot product.

#5

dfrobot: HI:

The romeo servo terminal has auto switch feature which will automatically select power from USB/Power Jack or servo terminal. Look at the schematics, the servo power terminal will not power Atmega328 and won't damage your romeo board.

Thanks.

dfrobot: So, no worry. if you have anything wrong with power supply. We have tried everything possible to protect your investment.

BTW, the DFRobot LCD shield you mentioned is probably the old version which has been updated with the latest version that supports brightness adjustment.

And, if you buy our product from ebay, be careful of the fake version of DFRobot product.

I bought it from one of your official distributors (robotshop.com) on May 31st, in order to get US shipping. Now, it may be they had old stock at that point, or perhaps I got the new version, but the warnings had not been updated. I just checked over at http://www.robotshop.com/productinfo.aspx?pc=RB-Dfr-07&lang=en-US, and they still have the warning about using pin 10. If you have updated the board recently, I will try it tonight to see if pin 10 changes the backlight to see if I got the updated board or not.

#6

As a followup, thanks to dfrobot for indicating that the new model lcd shield does support pin 10 to control brightness, and robotshop.com needs to update their wiki pages. It looks like pin 10 should be set to values between 1..255.

#7

Great to hear that yours is working. We will inform robotshop to update their wiki page...

#8