Let's Make Robots!

Mr. General questions

I've been looking into building a robot, and I found the Start Here robot and this site.  I liked it, but after looking around more I discovered the Mr. General kit, which seems to be more versatile for about the same price.  It's also more complicated and doesn't come with a handy step-by-step set of instructions to completion.  I'm not that experienced, but not a complete novice at this sort of thing-- I've made a 555 based dice roller and a (mostly nonworking due to wheel issues) simple light follower.  I can solder, read resistors, and know not to put LEDs in backwards.  I've done BASIC programming, but it was years ago in high school.

I've basically got two questions:  First, what sort of difficulties am I going to run into with the Mr. General that I'd avoid with the Start Here Robot. Second, know I need a CPU, and I was planning on getting a PICAXE chip (what version would be best? 28x1?) and a cable for it.  What else will I need?  Do I need a recieving plug for the USB cord?  Any other parts to connect the chip to the servos or the sensors?  I've got resistors, diodes, and caps. 

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Hey Atom,

 

After reading Oddbots reply I realised I actually had the Mr Basic NOT Mr General.  Apologies for misleading you.

 

Pete

I've decided to go with a Mr. General.  I'm sure I'll be back with some questions when it comes in.

The Mr. General kit is similar to a start here robot but with a compound eye mounted on a pan/tilt kit. It was designed for to work with any processor and therefore was impossible to give comprehensive instructions for complete beginners as every processor has different IO pins and programming requirements.

You will need to understand your MCU and how to use it in a breadboard. Basic electronic and soldering skills are required. Some components can be damaged by excessive heat when soldering. If you are new to soldering then get someone experienced to help you.

Because servos are used, controlling Mr. General is very easy. The servos plug directly onto the PCB. A jumper wire then connects the signal wire of the servo to the MCU.

The corner sensors have analog outputs that will connect directly to either analog or digital inputs. When connected to a digital input the input will go high when the object is about 1/2 of the distance that it could be detected with the analog input.

There is sample software for both picaxe 28X1 and Arduino Nano available so you can use the subroutines provided to make programming easy. The software is well documented with comments on most lines to explain how it works.

I've started with the frits "star here robot" ver II with the SRF05 sensor,than added tracks to the robot a few days after. I like the picaxe 28x1 and to me it's a good start in BASIC. Lately I've purchased the Arduino kit to try it out and see if understanding C programing will be better for me. Now it's up to you. Take care.

korel

Hi Atom,

 

I've purchased two Mr Generals and have been unable to get either working - it just strips the gears for me.  Very unhappy with the design. You will also need a form of motor controller for Mr General as the uMC pins cannot provide enough power to drive a motor direct.  With the Start Here robot yuo are only providing the control signals to the servos.

 

Hope this helps

 

Pete

It sounds like you have not wired your kits up correctly. All the motors are servos so you do not need any motor controllers. If you had any problems you only had to ask for help.