LED Cube 8x8x8

Step 46 Program the AVR with test code

Time to test if your brand new LED cube actually works!

We have prepared a simple test program to check if all the LEDs work and if they are wired correctly.

You can download the firmware test.hex in this step, or download the source code and compile it yourself.

As in the previous step, we use avrdude for programming:

• avrdude -c usbtiny -p m32 -B 1 -U flash:w:test.hex

-c usbtiny specifies that we are using the USBtinyISP from Ladyada -p m32 specifies that the device is an ATmega32 -B 1 tells avrdude to work at a higher than default speed. -U flash:w:test.hex specifies that we are working on flash memory, in write mode, with the file test.hex.

Comments

[stroodlemuffin]

I was able to upload and execute the test.hex program, but I had to hit the RS232 button to make it go; however, I am not using an RS232 cable. I uploaded the main.hex code and main.epp code but I got nothing from my cube upon pressing the RS232 button. Anyone have a fix?

[triumphtotty]

The source code for text.hex wasn't released, but possibly it runs if EITHER button is pressed.  My best guess is that the wiring for your start button is incorrect.  Check SV1 and SV2.  Do both status LEDs flicker at startup?  Check BTN1 thoroughly by following the wiring from GND to the microcontroller.  One side of BTN1 should go to GND, the other to Pin 16 on SV1.  Pin 16 on SV2 should go to Pin5 (PB4) on the ATmega32.  Check that out.

[stroodlemuffin]

I'll try that asap. What is the value of the resistor that goes from pin 9 (reset) of the Atmega32 to VCC? I currently have a 100 ohm resistor placed there as I could not get a definite value from this tutorial.

[triumphtotty]

100 Ohm is far, far too low I think. 10K is recommended. I think I used 3K3 because I had them lying around, but 100Ohms dropping 5V will draw 50mA from Vcc when the programmer is trying to bring the system into _RESET_. It's only a signal wire, not a current carrier. Try something a bit bigger, and hopefully that will help!

[stroodlemuffin]

It works great now, thanks! Was the cube set up so that you have to press button 1 to make it start? Because I hit restart and nothing happens but then when I hit button 1 the program starts. Don't really care, but just curious.

[triumphtotty]

Yes! When you power the cube up the two status LEDs should flash. You either press BTN1 to start the internal effects, or BTN_RS232 to switch into RS232 "slave" mode. So glad it's all working now. Well done!

[natekling]

Is there a C code example file?

Thank you.

[fluetke]

(removed by author or community request)

[triumphtotty]

The full C source code is available in Step 49: Software Introduction. Most of the hard work is done by draw.c, and effect.c has some great code in it. main.c has the interrupts and startup code in it.

[berto147]

when using command - avrdude -c usbtiny -p m32 -B 1 -U flash:w:test.hex
it replies with error opening test.hex: no such file or directory
I have downloaded the test.hex file and saved it , is there a specific location I need to save this file to in order for it to be read

[triumphtotty]

It should be in the current folder as you type the command. Are you working in Linux or Windows?

[berto147]

i am working in windows

[triumphtotty]

Depending on where the file is, you'll need to "cd" into the directory.

e.g. if it is on your Desktop in a folder called 8x8x8 then type:
cd Desktop\8x8x8

then type your command.

If it's somewhere messy, e.g, just create a new folder in C:\ called 8x8x8 and move/copy the test.hex file into it, then type

cd \8x8x8

before typing the avrdude command.

Hope this helps.

[berto147]

i will try this on friday , i have had to go to scotland to work for a week , many thanks for your help

[00cwilkr]

hi mate your link to test.hex doesnt go anywhere?

[TechNotes]

What you do is right click on test.hex, and select "Save Link As...", then save it to wherever you want.

[mnpumar]

Does anyone know where to put temp.hex in windows or how to specify the path?

[TechNotes]

What you do is right click on test.hex, and select "Save Link As...", then save it to wherever you want.