This web page is run by me on my spare time. If you find any of the information useful and worth a couple of bucks, I will be very grateful if you buy me a beer by donating a small amount using the PayPal link below :)
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DIY microstepping motor driverWith the introduction of the A3977, and now recently the upgraded version, A3979, Allegro microsystems have made stepper motor driver design a simple task. The A3979 is a complete stepper motor... Read more...
DIY Roomba USB interface cableThe newer models of Roomba vacuum cleaners from iRobot feature a serial interface, enabling remote control and debugging of your Roomba. Here I will describe how you very easily can make a cable... Read more...
I recently bought a SIP Migmate 150 DP gas/gasless welder, and as my first project using it I started building a cart for my welder. But when I started welding I was puzzled by the bad results I got. I have not been welding for may years, but then using a PRO ESAB welder. But now all my welds where really bad, and with a lot of splatter. I noticed that the wire feed was very uneven, and googling around I found a lot of information about this brand of welders and their inherent wire feed problems. In addition to the wire feed problems I had several occasions of porous welds, indicating that there was problems with the gas-feed.
As I have had quite a few requests from people that want to buy PCBs for my stepper motor driver design, I have added a simple webshop solution. Currently there are only two products, the stepper driver PCBs, and the A3979 stepper motor driver chips. But as my other projects progress, I might add some more products in the future. Currently I accept PayPal (allowing you to pay with creditcards even without a paypal account) in the webshop, and will soon hopefully also add support for moneybookers. Read 0 Comments... >>
It has been quite a long time without any updates to my site. Partly this has been due to all my time being tied down with my day-job, with no spare time for my hobby projects, partly it has been due to travelling lately (both work related and vacation), and partly due to my work in updating the site design and moving the site to a different host.
Finally the site is back up running on the new host, and I have started to get some time to work on my hobby projects again. As summer is marching on updates might not be too frequent still, but at least I am back with progressing on some of my hobby projects on the rainy days :)
As the site has been moved to a new host, it could affect the operation of the site, even though I have tried to test everything. Still if you find any dead links or malfunctioning functions of the site, I would be extremely greatful if you would contact me and let me know.
Edit: Ironically I just discovered that the contact form did not work Should be fixed now. Read 0 Comments... >>
I have just finished an update of my sherline CNC mill article describing how to connect my stepper motor drivers to the motors and a computer, and configure the EMC2 CNC software for using them.
For my CNC project i originally intended using my converted PC power supply for powering the stepper motor drivers. However when testing the CNC mill I soon found that applying higher voltage significantly raised maximal speed and torque in my system. Therefore I needed to make a power supply with higher voltage output. As my stepper drivers have a maximal voltage rating of 35V I aimed at 32V output. And as the current rating pr driver is 2,5A I wanted to be able to supply at least 7,5A.
Here I will show you some techniques for soldering very small, fine pitch SMT packages using standard soldering equipment.
These techniques will help you to master the SMT soldering skills needed for assembling for instance my stepper motor driver board.
The methods described here are based upon my personal experience working with electronics for several years, but there might of course be other methods as efficient (or even more efficient).
After short time my Roomba would no longer dock correctly. It tried docking but did not seem to detect the docking station/home base. However when plugging the charger directly into the Roomba it charged correctly. Here I will show the process of finding the fault and fixing it.
RC servos have for a long time been the component of choice for robotics animation. They are relatively cheap, offers good torque/current relationship, and are easy to control. Applying a digital pulse, positions the servo in a position relative to the pulse width. But on a robot with many moving joints, e.g. a 18 dof hexapod, relatively heavy processing is needed to generate the pulses for all servos, especially if variable speed, and fluid simultaneous movement of the limbs are desired.
For my next CNC build I am going to make a PCB router, based upon a Proxxon KT70 compound table, and a dremel rotary tool.
I need to ensure that the steppers I select do have enough torque to turn the leadscrew, and therefore needed to find the minimum torque needed to turn the hand wheels. But the torque wrenches I could find in nearby tool stores where not suitable to measure such low torque values, so I needed to find the torque in a more practical way. Here is the description for my "Torque Approximator" setup.
My new stepper motor driver PCBs have finally arrived. I will soon have them assembled and ready for test. My main concern is whether or not I will be able to run them without a heatsink attached.
The boards are all SMD components, and to help anyone that would like to make their own boards, I will write and post a small tutorial on how to solder SMD components using standard soldering equipment. It is actually not that hard as long as you know the technique.
EDIT: Sept 21. The boards are now assembled, and are working perfectly. No heating when running the steppers, but still relatively hot when holding the steppers steady. I will try to get hold of a surface thermometer so I can measure the heat built up on the htermal pad, to determine wether a heatsing s required or not.
When I started using the AVR micro controllers back in 1999, I coded most of my applications in assembly. After a while GCC for AVR became available, and now, with the integration of GCC support in Atmels AVR studio, starting with GCC for the AVRs is now as easy as coding in assembly.
Atmel recently introduced the XMEGA AVR devices. These devices give a nice addition to the AVR family, introducing several new features ideally suited for robotics. Is this the perfect microcontroller to be used as a robotics brain?
I recently bought a SIP Migmate 150 DP gas/gasless welder, and as my first project using it I started building a cart for my welder. But when I started welding I was puzzled by the bad results I got. I have not been welding for may years, but then using a PRO ESAB welder. But now all my welds where really bad, and with a lot of splatter. I noticed that the wire feed was very uneven, and googling around I found a lot of information about this brand of welders and their inherent wire feed problems. In addition to the wire feed problems I had several occasions of porous welds, indicating that there was problems with the gas-feed.
As I have had quite a few requests from people that want to buy PCBs for 
It has been quite a long time without any updates to my site. Partly this has been due to all my time being tied down with my day-job, with no spare time for my hobby projects, partly it has been due to travelling lately (both work related and vacation), and partly due to my work in updating the site design and moving the site to a different host. 
Should be fixed now.
I have just finished an update of my sherline CNC mill article describing how to connect my 
For my CNC project i originally intended using my 
Here I will show you some techniques for soldering very small, fine pitch SMT packages using standard soldering equipment.
After short time my Roomba would no longer dock correctly. It tried docking but did not seem to detect the docking station/home base. However when plugging the charger directly into the Roomba it charged correctly. Here I will show the process of finding the fault and fixing it.
RC servos have for a long time been the component of choice for robotics animation. They are relatively cheap, offers good torque/current relationship, and are easy to control. Applying a digital pulse, positions the servo in a position relative to the pulse width. But on a robot with many moving joints, e.g. a 18 dof hexapod, relatively heavy processing is needed to generate the pulses for all servos, especially if variable speed, and fluid simultaneous movement of the limbs are desired.
For my next CNC build I am going to make a PCB router, based upon a Proxxon KT70 compound table, and a dremel rotary tool.
My new 
When I started using the AVR micro controllers back in 1999, I coded most of my applications in assembly. After a while GCC for AVR became available, and now, with the integration of GCC support in Atmels AVR studio, starting with GCC for the AVRs is now as easy as coding in assembly.