Saturday, 20 February 2010

8x8 dual color LED matrix

...arrived from oomlout last week , it's a common anode model, which is a bit problematic fom my perspective in driving it, but no matter.

Here are all the green LEDs.
As one would expect, the drive voltage (current actually) for the RED and green LEDs does differ, but since the control will be pulsed anyway, controlling the pulse width a little should give a controllable mix, because the red LED in the dimple is pretty bright. My intention is to use some shift registers, a transistor bank of drivers, or to swap my prorgam's algorithm completely and drive the rows with drivers, and the columns with the micro directly. I'm waiting for a TMP36, the one mointed near top-right of the microcontroller (it's hiding under a bit of veroboard) was actually toasted, so I had to order another, it's still comming because I made a mistake in the ordering process by not actually paying.

Thursday, 11 February 2010

USBASP programmer working on Windows 7 x64

It as not my brightest moment, but it has improved out computing experience at home, upgrading my XP to Windows 7. BUT, it broke the Usb driver, because Microsoft decided that signing all drivers without exclusion will improve the customer computing experience... I hate going outside the box to break my system, but I need my usb programmer to work so...

1. download driver from
2. Plug in device, browse path to downlaoded files
3. Install fails... no worry.
4. download DSO version 3b from
5. Run it, and select "sign a driver". browse to the driver c:\windows\system32\drivers\libusb0.sys
6. Put DSO into test mode
7. Reboot - it (should) now work

I think you can skip step 5