Wednesday, December 31, 2008

MyChicA Biped Robot got a new trainer...

MyChicA is evolving rapidly... from crawling few days ago, she just recruited a new trainer... yeah, yeah... I had to develop the trainer... Written with Visual Basic, the trainer communicate with MyChicA via RS232 at 9600bps. I decided to slow down the comm speed to allow more processing to be done within MyChicA little brain...

The trainer/tester is meant to control the servos in order to develop the various gaits position for MyChicA. Once the optimum values are found, they will be embedded into MyChicA brain so she can perform those tasks autonomously...

I love holidays... once the new year starts, I'm not sure I have the time to pet my beloved MyChicA and teach her new tricks... :-)

Tuesday, December 30, 2008

Epson R290 CISS Modifications

Several sites and youtube videos already showed how to install the continuous ink supply system (CISS) on to the Epson R290 printer. All of them require that the ink cover be permanently removed to allow for the tubings to be installed. That's exactly what I originally did but not without problems.

The CISS that I bought uses soft plastic for the ink catridges thus when placed into the ink compartment, it doesn't fit tightly causing the the electrical contacts to be intermittently broken. When this happens, the printer driver will complain saying that the ink is not Epson original thus refusing to allow any printing. In the beginning, I placed some wood wedge to force the cartridges to snug-fit.

Although it worked, it became an unbearable hassle to me. Furthermore, every time the electrical connection is re-established, the printer will recognize the cartridges as new so the cleaning cycle will start thus unnecessarily wasting the inks. I finally decided to give another method a try. Using cutter, I snip the original cover to make way for the tubings. Once that is done, I refitted the cover back to the original position. Lo and behold, it worked like a charm... no more wooden wedges, no more lose connections... I'm a happy man once again...

MyChicA Got Her Brain and Juices...

After my fun-filled holidays with the family, managed to put my hands back on myChicA project. MyChicA now has a brain and power plant. The brain is in the form of Microchip PIC16F876A processor running at 20MHz capable of driving 8 servos with about 200ns resolution. It can communicate with host PC on RS232 interface at 19200bps with no problem. Several spare connectors are on board to allow for future expansion and/or experimentation. So far, myChicA can walk forward and backward with no problem albeit a bit jerky. Software improvement is in progress...


MyChicA with the controller board and batteries (4xAA not visible + 9V) installed.


Let the coding begins...

Wednesday, December 17, 2008

MyChicA Biped Robot... The beginning

After much consideration, I decided to start with the basic 4-servo biped. Using the concept from Loki as basis, I went on to design my own. Managed to find the time to cut it on my Sherline CNC using 3mm colored acrylics. So far, all the mechanical work is done. Time to dwell into the electronics.

I gave it a name... MyChicA (pronounced my-chi-kar)...

Loki reminds me of a chicken thus my biped is a Chic. The A is for version 1 as I'm sure more siblings will appear :-) Without the electronics and battery, MyChicA could hold it's posture just using the servo mechanical resistance, as shown below.

Will be updating the progress later... not so soon... going on vacation with the family first... :-)

MyChicA and the twin, Loki... :-)

Monday, December 15, 2008

Amateur Radio Reunion Day 2008 (ARRD08)

Update 2008.12.15: Individual photos can be accessed from Photobucket using this link (ARRD08 Photos)

Just came back from the said event last weekend. Huge turnouts, youngs and 'seniors'... Weather was good albeit a bit too hot...

Below are the contact sheets of the photos I took during the event. Need to find time to upload it to online photo site. Used the opportunities to meet friends and learn how to use the new D80... :-)




Wednesday, December 10, 2008

Nice... ooohhh... simple BiPed... the Loki

Still deciding which robot to build first... either the unit posted before this or this Loki... this Loki looks cute... simple to make... less servo... simpler parts... hmmmm


Also for those keen to have a nice toy, the i-Sobot is now available in Malaysia for under RM1000. Very tempting looking at what its can do... check out this youtube video.

Thursday, December 4, 2008

New interest... biped (walking) robots....

I have been always interested in humanoid robots. After buying a cheap one for my kid, I decided to make one for me :-) After the usual search on the internet, the kit from Lynxmotion attracted my attention but the price it more than what I'm willing to pay for... I'm starting the research on the basic mechanical design now and will be updating this blog with my progress... anyone else want to join me? I'll be firing up my CNC again for the frames...

On the topic of white balance...

With my new D80, I'm back to snapping photos. While browsing an online photography store, I came across a product called 'Warmcards'. The package comes with several colored cards to adjust the white balance of the camera. Ever wondered why people in your home video look pale and uninteresting? The answer lies in white balance. Most professionals adjust the white balance to make the photo/video look warmer. Refer to warmcards website on how to do this. The image below (image from warmcard website).

The original Warmcards package look as follows:

But, as always, in the spirit of DIY, I decided to make my own cards. After a quick search on the internet, I gathered enough information to print my own cards to test out. To my surprise, it worked extremely well (although I have no idea how the original cards would be different). My homemade cards were printed with the EPSON R290 printer on matte, resin coated, water proof paper. I later laminated the back side to stiffen the card. The matte finish minimize reflection, water proof so I can wipe it clean if I needed to... :-)

For those wanting to give it a try, here's my test layout... btw, the CYMK values used are from the internet and not necessarily reflect the values of the original warmcards.