X-Pod Update

Slowly making progress, I have been kept busy with some stuff lately.

Struggled with timer interrupts for a while because it kept interrupting serial communication, making the robot twitch every 3~5 seconds. (although it was sort of entertaining to watch). I am trying various approaches in terms of programming.

It is slightly disappointing that the servos I have do not provide direct feedbacks from its integrated potentiometers. I have to query their position using a command in software and there is a 50uS to 5ms delay before its position is reported back. Maybe digital ones will have direct position feedback? But they are very costly though.

Still needs a lot of work.

Servo offsets have been adjusted in software, created initial sequence movements for X-Pod and struggled with timer interrupts.

Oh, the little transformer I was using for battery charging circuit is dead but found a better one in one of my box of random electronic goods. The old one was only rated for 400mA max but the new one outputs 1.5A. Much better.

I will post some pictures and videos soon.

X-Pod [ Here we go ]

Still need to clean up the wiring, and adjust servo offsets.
Notice I was moving 1 servo with the PS2 controller; that was setup from previous test run, and got kind of carried over.
I should be ready for some programming very soon.

[ X-Pod ]

Accelerometer

I am trying to find a way to change the reference voltage for A/D so that I will be able to get better resolution from 3 axis accelerometer, which outputs 1.33v ~ 1.99v each axis.

I was reading Basic Atom (not pro) manual and I noticed that it had the capability of setting AX3 pin as a voltage reference pin by using the parameter AD_RPOS... But I don't think BAP28 (Basic Atom Pro 28) has that capability because there is absolutely no mention of such feature in BAP28 manual.

I found this
http://forums.basicmicro.net/viewtopic.php?f=486&t=8931&sid=d52c99a731e39aa83550091fbadd1c76

which sugguests a whole lot of nothing.
No Vref? Very disappointed, especially since I could've potentially doubled up the resolution of the sensor, which is a big deal!

I thought of a possible solution... I could build an amplifying circuit using Op-Amp, and just boost the 3 analog signal coming from the accelerometer... I'll leave this option as my last resort. I will probably just go with what I have now and see if I have any stability issue with auto-balancing.

Ping Ultra Sonic Sensor Distant Measurement

Remote Control

Walker Project [ Still Under Construction ]

I came to my senses and removed the feet on both sides. Now none of HS-422s are being used, and it's probably better that way. I might add a servo to the PING sensor for panning capability, but that might interfere(mechanically) with the electronics which haven't been mounted yet.

Hardware Connection (Testing)

Walker Project [ Under Construction ]

This is it for today, will continue tomorrow!

Progress

[ New servos have arrived! HS-645MG ]

+ 10 of HS-422 ... But only 2 of them are going to be used for the time being.

[ What a difference ]

The one on the top is HS-645MG, and the one below is HS-422. There's a huge difference in torque as well.

[ This is the new design, although it's missing some parts ]

I am expecting another shipment tomorrow. Pretty soon I will be doing some intense programming!

UC232R-10 "CHIPI" cable, manufactured by FTDI

This is the cable I purchased from Digi-Key.

Works flawlessly at the maximum baud rate of 115.2K
Didn't even have to download a driver for it either. I plugged it in, and Windows 7 installed the driver for me.

I am very happy with the purchase.

Highly recommended!

Major turn over

I received a brand new credit card last Friday and because my order was still pending, my entire shipment from Robotshop got cancelled. I did receive my cable this morning from Digi-Key though.
On the side note, I have been doing some researches on the internet for my project and I might use this opportunity and take a different approach in terms of mechanical design.