BUTTERFLY AUTOSTARTING USER PROGRAM:

I have the Butterfly. It's easy to program with just an RS232 cable and WinAVR. At least that's what I thought.

Now I need to program it so it will run my program after a reset, instead of running the "bootloader" program.

It seems I could do that by changing a fuse or changing the "bootloader". If I understand the situation correctly I will need to buy some hardware to do this. Like the stk500. Is this correct?

I thought that it would be possible to program the AVR butterfly using only RS232. There are several web sites suggesting that this is true.
For example: <http://www.dwelch.com/avr/> Isn't this correct?

I don't really want to get rid of the bootloader. I just want it to run my program when it's powered on. I think there are at least two ways to do this and both require some programming hardware.

I can change the fuse so it will run my program after reset. I can then get to the bootloader from my program by jumping to it when I want to update the software. If my program gets corrupted, I can use the programming hardware to change the fuse back to the original setting.

Another approach would be to change the bootloader program. If it would check a joystick switch initially, and jump to the user program if the switch wasn't closed, this would work and would allow use of the bootloader by pressing and holding the joystick when resetting the board. I do think I will buy the ATAVRISP.

There is a JTAGAVR device selling for $37.95 that looks interesting but unless someone here will recommend it, I'll stick with Atmel's ISP thing.

I never used JTAG and I don't need it, but it would be nice to have if it works. But the procedure and hardware required to update the microcode has scared me off of that thing.

Naa. That's too easy Now why didn't I think of that? It looks like a simple jumper would do it. PB6 is next to ground at the port B header connector.

BUTTERFLY CONNECTING ADC:

This is probably pretty basic, but I'm a software guy just starting out on this project. I want to connect a sensor to one of the Atmel Butterfly spare A to D inputs. The sensor I am connecting requires a 10k load. Does this mean I that all I need to do is put a 10k resistor on the negative side of the sensor and connect it to ground, or is there more to it than that?

It is the teledyne r-17. Thanks for the speedy response.

BUTTERFLY RESET/RESTARTING:

I wrote some code to do some testing for my project using the butterfly and forgot to leave the bootFunc code in. I programmed the butterfly thru the use of the bootloader on the original code, now my butterfly doesnt' look like it's working with the new code and I've lost the capabilities to program it too.

Is there a way for me to get access back into the butterfly without the need of the JTAGICE, AVRISP, STK500?? I just wanted to know if there was any other way I could just reprogram my butterfly back to normal using just serial, but I think my work's got an AVRISP, but I'm not sure if it has a 6 pin or 10 pin cable and I won't be able to get there for a couple of days.

Thank you for you help!

BUTTERFLY PORT E VOLTAGE:

When I set some port E pins as output on my mega169 they immediately have a high level. I expected the output level would be low, until I set them high.

When I run my software on the simulator, the output pins are low.

Is there something wrong with my mega169?

It's not the pullups. They can't source this much current and they wouldn't be enabled when the pin direction is out. At least I don't think so.

I didn't explain the situation very well. I can set the output high or low but I expected these pins to start out low.

I think I have the answer though. The PORTE register is 0xff when my program gets control. On the Butterfly my program doesn't get control from reset directly. It gets control from the "bootloader" program. So I guess the "bootloader" is setting the PORTE register to all one bits.

The bootloader reads some of the switches on the joystick and some of the port E pins are used for that. So the guy that wrote the bootloader probably set all the pins high to make sure he got the right ones.

Okay, just as I suspected. I looked briefly for the bootloader source but all I found was the app note 109 stuff that didn't read switches.

BUTTERFLY LCD DISPLAY OF CURRENCY:

Hello all, I am new to the embedded programming realm. I am trying to make a cashless smart card system to take the place of bill acceptors in the vending industry. I was wondering if the AVR Butterfly board is a logical solution to use to communicate with a smart card reader/writer over the rs-232 protocol.

I have noticed that many smart card reader/writers come with drivers the are designed for the pc. In my scenario, I don't have a pc that will be doing the communicating. I need a microcontroller board with an LCD display to display the dollar amounts stored on the smart cards.

I am about to purchase the butterfly kit along with a rs-232 card reader/writer. I was just wondering if this is the right way to go........

Any advice would be greatly appreciated. Thank You!!

Will it allow the six digits along with the dollar sign and the dicimal point????

BUTTERFLY PROGRAMMING VIA CODEVISION & STK500:

I have a butterfly connected to an stk500 via the isp connector and I am having problems programming it.

It worked once but I think I may have not programmed the clock select fuses correctly and now I cannot program it again through the isp port.
Is there a way to reset the fuses so that it uses the internal clock.
I have tried to read the fuse settings with AVR Studio but it says there is a problem reading the fuse settings.
I used Codevision to program it initially.

BUTTERFLY RS232 CONNECTION TO TERMINAL:


I just bought my butterfly and hooked everything up through USART. To test my serial connection, i went into the NAME application within the butterfly and typed out my name in HyperTerminal and it worked fine. It got my name and wrote it on the screen.

I then tried programming the latest version (revision 6) onto the butterfly and that worked fine too. I read the flash and eeprom first to keep as a backup of the original image.

Aparently, however, in my terminal program, i'm supposed to be able to also RECEIVE text from the machine. If i click it in, i'm supposed to receive ?????, which i dont. I cannot receive anything from it. If my receive was broken, how was it able to read the EEPROM and Flash (with valid data in the files), but not send debug info like that?

Anyone know what i might be doing wrong?

Yeah, i followed your instructions, and didnt get the ???? when you said i would. After checking everything 100 times, i tried sending and that worked and also programming worked... i wonder what could be wrong.

Yes, i did try bray's terminal and am having the same results. Have you seen this before though? where you can only send and not receive?

Wow! ok. By doing a bunch of shorting of pins i indirectly fixed my problem. As with all of these "impossible" errors, its a user error. I assumed the device had to have "AVR BUTTERFLY" scrolling while pressing center. Little did i know that it had to actually be reset with nothing on the screen for it to work

BUTTERFLY CLOCK SPEED:

I don't manage to determine the clock frequency of the ATMEGA169 in the AVR Butterfly board.

I have read the datasheet for atmega169 and the user guide for the Butterfly back and forth to no avail.

Here is what I know:

there is a 32kHz xtal connected to TOSC1
The lock bits at 0xE2 CKSEL read external crystal, 3 - 8 MHz, which matches the "Advanced..." screen of AvrProg.

The clock prescaler CLKPS reads 02, meaning a clock division factor = 4

ASSR reads 0x08, ie bit4 is false, ext. clock NOT selected, bit 3 is set, async timer2 clocked from TOSC1 pin.

Does that mean the MCU runs at 32kHz devided by 4 (prescaler) = 8kHz.

I simply cannot imagine that it runs a factor 1000 slower than what is possible (8MHz if run from the internal RC clock)

Where is it described and how can I verify the cPU clock?

I expect the main reason for having the 32kHz XTAL on the Butterfly is the option to drive a timer in async-mode so the AVR can enter a "deep" sleep-mode and also keep the RTC up to date.

First: I was told that the internal oscillator is not accurate enough for an RTC, so wouldn't the main reason for having it be to have an accurate RTC period, not just so it can sleep.

Second: Isn't the internal oscillator even uncalibrated accurate enough for 19200 USART communications?

BUTTERFLY PIEZO OR SPEAKER SOUNDS:

Recently someone asked me if I could implement a simple application that, among other things, emits a "wolf whistle". (Is "wolf whistle" strictly a North American term, or is it a well known term internationally?) The application is a "joke" item.

Anyway, my friend had the idea that it could be stored as a WAV file (or some other audio format), but I am thinking that it should be fairly simple to implement it as an algorithm, instead, all in firmware. The whistle could be emitted via a piezo transducer with, maybe, a simple RC filter between the AVR pin output and the piezo (maybe an op-amp to boost it, if needed).

Has anyone ever done this, or know where I can find some "wolf whistle" parametric details (frequency, timing, rise and fall rates, etc.) on the web?

Thanks for the reply. I figured it would be something like that (off the top of my own head!) But I was wondering if the frequency sweep would be linear or if it would be some kind of curve (logarithmic, sine, or something). Anyway, it's probably so simple I could even do it in assembler!


Any ideas on what to use for a cheap transducer if a piezo will not do?

BUTTERFLY PROGRAMMING:

I´ll get straight to the point.
I´ve toyed around with my Avr Butterfly for a while and just started to try sending software to it. The guide I used was the Quick Start Guide by Joe Pardue, it´s a good one I might add.
Now, when I downloaded the code I must have clicked EEPROM instead of FLASH, the programming worked and the Cylon LED worked as well.
But how do I get the original boot menu back?

The ???s are appearing ok and the AVRProg window appears ok..
What I´d like to do now is to get the old Butterfly LCD meny back. I can re-download the Cylon blinky to the flash but when I try to re-download it to the EEPROM the AVRProg-window freezes and has to be terminated. Any guess?

I got i working again
A humble thank you is in order. That was a sure reminder of my youth and all those broken PCs I left behind in the learning process

AUTOSTARTING BUTTERFLY USER PROGRAM:


I have an application running on the butterfly using WinAVR. How can I make it start automatically instead of having to push the up joystick?
I see that there is a fuse that makes it jump to my application directly, but the data book states the Boot Reset Fuse cannot be programmed from MCU, so do I need to hook up STK500 directly instead of using serial port and AVRProg? (I'm lazy.) Is there a way to do this over the serial port?
Also, why does the boot loader require the joystick be held down(enter) to get AVRProg to work? Is there a bootloader for Gcc that doesn't require this?
Maybe the idea is a bootloader that looks for AVRProg briefly and then jumps to application code. Does this exist?

What I wanted to do was have a way to have the butterfly automatically run my application without having to press the UP JOYSTICK command, and I wanted to be able to do it using the serial port programming.

BUT, You can't overwrite the boot loader using the boot loader, can you?

I made modifications to the boot loader so it would time out after sending a few "?" and run my app.

But when I tried to load the program it croaked and then my butterfly became unusable until I restored the original boot loader code using the ISP 6 pin header on the STK500.

I tried it again and the same thing happened. Then I tried flashing my modified boot loader using the STK500 and it worked.

The program that is writing the flash is executing from the flash which I'm trying to write. Probably a very bad idea.

I guess you could do something heroic like write a boot loader that ran in the application area and use that to update the real boot loader but I think that is too much work for dumb old me to ponder.

I did make a very easy modification to the boot loader so it puts out 25 question marks (to start the AVRProg if present) and then jumps to the application code (if not present). It's a bit difficult timing wise to force a reset by lifting the battery while you click on AVRProg with the mouse but it is do-able. (A reset switch would be a LOT easier!) So now my application can be field updated by anyone with a pc and serial cable.

It was very simple to do this modification once I figured out that I had to use the ISP to program the boot loader, but if anybody is interested I'm happy to post the mod.

BUTTERFLY TEMPERATURES:

I've been playing with my Butterfly, and my temperature reading is high by about 10 degrees Farenheit.

Right now in my house it reads 81 degrees F and 27 degrees C, and it's probably about 70 degrees F.

Has anybody else had this problem? I can't think of a good solution since I think I would have to change many values to recalibrate it.

I can code it with GCC if anybody has any ideas.

I found a solution, and I am surprised at how accurate it is now! I walked up to see if if matched my thermostat and it read the exact same temp, and then I drove around with it with my top down and it matched my car temp exactly.

I just adjusted the ADCresult value if the ADC was reading tempurature. If you are familiar with some of the GCC Butterfly code you may know what I'm talking about. I added 70 to ADCresult.

ACCESSING BUTTERFLY ADC PINS:

Can't figure out how to access the analog comparator of the mega169 chip on the AVR Butterfly. I have been looking at the mega169 data sheet and what I need are pins 4 and 5. According to the avr butterfly these pins are connected to the joystick??

I need to feed a signal to the analog comparator on the mega169. I would also like to set a reference voltage. Has anyone any idea of these pin connections as I cant see it? What pin on the butterfly do I connect my signal to get it to the analog compartor?

I am going to solder directly onto the joystick pads.

I still have a problem-from looking at the joystick schematic I can see there is 6 pins but how do you know which pins are which on the butterfly??

On the joystick on the butterfly there are 3 pins on top of the joystick and 3 pins below the joystick. Which pins are PE2 and PE3?? I have tried to attach the schematic but it is not working for me.

Unless I am totally daft Atmel did not follow the drawing above. I have pins 4 and 6 reversed from the above drawing, in other words the pins go 1, 2, 3, 4, 5 and 6 in a counter clockwise fashion. I measure PE2 connected as shown above to pin 3, but PE3 is connected to the diagonally opposite pin (pin 4 as shown above, not pin 6 as the schematic states). I measure PB7 connected to the pin directly opposite pin 3 (pin 6 as shown above, not pin 4 as the schematic states).

BACKLIGHTING BUTTERFLY LCD:

So, I would like to backlight the LCD on the Butterfly.

I have some surface mount LEDs that I could do some side lighting with, but I don't think it would turn out that well.

I am thinking about using the Butterfly in my car and mount it into the dash. So, of course, I would need some backlighting.

Anybody have any ideas? Has anybody tried this?

.


The datasheet for the LCD specifies the rear polariser as being transflective.
Could somebody explain what transreflective means?

Wow, how would you suggest I desolder the LCD? I would be afraid of ruining the whole board. I have a tempurature controlled iron, but I don't have a hot air reworking station.

BUTTERFLY JOYSTICK USAGE:

I've been trying to use the joystick of the Butterfly for a while but I have some problems...

As I have understood in the datasheet (ATmega169), there are a lot of external interrupts (PCINTx) on PortB and PortC. The joystick is connected on these ports.

So, here is my code :

It should light up a led on PORTB1 when I push the joystick right or left and light another one up when I push it on the other directions.

It works fine with left/write but it does nothing with the other directions...
So, I tried to put another switch on PB6 and with it, it works!!

So, am I wrong with the code? Is there someting special to do with this joystick?

BTW, I hear the buzzer when leds are on... I don't know why.

.

Yes, I think there is no enough docs about the butterfly!
I've already looked at the document and thanks for the buzzer! I disabled PB5 and I don't hear it anymore

But for the interrupt, it still doesn't work!
I've changed my code :

But it's still the same : With left/right, ok but with up/down, nothing!
Nothing? No! In fact, it works only the first time, when I push up the joystick, PB2 light on but after, I can't get any interrupt from it.
But with an external switch, it's ok !

Oh yes!!! Thanks a lot! You've found my problem : PULLUPS!
Here is what I put :

And it works! Thanks again!