Let's Make Robots!

Arduino Mega 2560 to run Programmable LED Strip, code difficulties

Dear LMRians,

I have bought an LED strip with chips WS2811, which has 3 wires, Data, 12V supply and Ground. According to the datasheet, the data had should be in the following way. I have some programming problems.



Questions on Extruder (delta 3d printer)

Hi LMRians!

My uncle and I are working on a 3d printer with delta mechanism! We have some questions about the extruder!

The speed (or power) of pushing the filament to the hot end? how much should it be? how it can be calculated?

We are looking for some cheap methods of extruder design! What do you recommend? because we no do not have access to any 3dprinter to use extruders on net! We have bought the hot-end of felix 3dprinter (with the stepper, thermistor and heater)

L297 and L298 problems

Hi LMRians!

I do not know how should i chose the amount of resistors needed for the currents sense pin of both L297 and L298! It seems that they control the amount of current flows through the winds of the connected stepper motor. right? but how much resistance they need? Surley, it is related to the stepper motor. how is it related mathematically?

Data for a Special Stepper Motor


I have bought an stepper motor but I can not find the datasheet for it. The Codes on it are:





I could not find the datasheet. How can I find it? I googled it but no benefit.

How can I find:

1- which wire is related to which step? Which wire is the Vss?

2- how much voltage does it need as a supply?


Thank u!


How to Control many 1 DOF small robots remotely


I want to make many 1 DOF robots (Maybe 7, 8 or more). They should be as light as possible! So I can't use many parts for each of them. Just a battery, a servo, a wheel and some kind of reciever.

I do not know what sort of remote controll is best for them. Maybe WiFi is good but I guess the robots will get heavy. I can not use the multichannels Transmitter/Receiver because they have just one receiver which can not be pluged into many bots away from each other. I need a receiver for each.