Let's Make Robots!


12V-30V Arduino Power Supply

So one project that I've been working on lately is a 24V Brushed Motor Controller Shield for Arduino. One of the features that the shield must implement is a power supply capable of power the Arduino with more than 15V, activates the Arduino when the input voltage is greater than 12V, and power any necessary gate driver circuitry. I finished Rev 1 of the power supply and plan to add one more revision to the power supply circuit before designing the reminding parts of the shield. 

My first PCB

Hi guys,

I started on some unfinished projects again but I could use some advice. I'm trying to build a board for the mini reef that can switch 6 devices (solenoid valves) at 12v DC with the PIC/Prop controller. I'm using diptrace for this as this seems to be the favorite choice. So far I love it.

I came up with the below but I'm running into some problems with the traces. Maybe someone can point out the right direction as I think that it must be possible to cross over a line (with some electonic component maybe)? The red circles are the problem areas.

Ultrasound navigation, reacts on nearfield bodyheat, detects light
Using a
This is my first autonomous 4WDBOT on a DfRobot Base.I try to keep all mountings as clear and functional as possible - no decoration parts. Update: After some … Read more

Battery Backup 12v

Hello, I wanted to add a battery backup to a Picaxe circuit so when the AC main fails the power will switch from the AC-DC transformer to a 12v battery which is then lowered to 4.5v to power the PICAXE board.

after some research I found this circuit which seems pretty simple and I wanted to know if you people think its good or will I have fried PICAXE for dinner.

Thanks in advance!  :D

Run 12V stepper with 5V??? [SOLVED]

Hey guys I have a quick question. I've never used a stepper motor before, but I have one that will fit my new robot nicely. It is a 12V motor kinda like the one below

12V stepper motor

I don't have a 12V power supply right now, only a 5V. I want to know if this motor works before I go and buy a new battery. Does anyone know if it will even work with 5V? I just need it to move just enough to let me know it works, then I'll go get a battery. 


i have seen this nice battery around called the t-1248a. it's a nice battery for portable applications. it can be fond with a charger on ebay for 27$. should i buy it