Axon with USB-Display

[PAT_McUser]

hi,
I'll need dome help again. This time my prolem is that I want to use a small 4x20 char display to promt status information of the Axon.
The small display has a USB Port and a I2C Master-Bus, its Power supplyed by the USB-Port (It can also be powerd by the I2C, but thats not documentated).
My first idea was a bit to easy, I tried to use the I2C on Axon and Display. This was a realy stupid idea, because you nead a Laptop or so on to give the display the order to read the external device. (Later I want to build a robot that drives arround, so running behnd it with my Notebook... ...crazy, don't wana do that.) So my "idea of the day" was to read the USB and"playback" the commands. (I hope you can follow me, I made a few pictures for you.)
I cut an old wire to connect my new outputs to the white and the green wire (Data +/-). So I get a part that alows me to read the Informaton, you can see it on the first picture (Green is markt with some rubbertape).



Next I connected the data+/- to my axon adc and write a small Program that throws the recieved data via rprintf into my hyperterminal.

Code: [Select]

void control(void){
rprintfInit(uart1SendByte);
a2dInit();
a2dSetReference(ADC_REFERENCE_AVCC);
while(1){rprintf("green: %d , white: %d \n",a2dConvert8bit(6),a2dConvert8bit(7));}
}
At least I attached my 7.2 Voltsopply to the axon and wired my connector to my Pc and the display.



My problem is that the display didn't do anything when I connect the axon (YES, I do run a demo Prog so the display should show something)
Whats running wrong?
I have get some data from the axon you find it here
http://freenet-homepage.de/chaos-user/AXON/test.TXT

[Admin]

Tell us more about the display, like a link, part #, how you wired it, power consumption required, whether you got I2C to work with other devices, if you made all grounds common, etc.

[PAT_McUser]

here are a few links about my display.
http://www.abacom-online.de/div/ABACOM_USB_LCD_uk.pdf (Description)
http://www.abacom-online.de/div/setup_usb_lcd.exe (Some examples and so on)]http://www.abacom-online.de/div/setup_usb_lcd.exe]http://www.abacom-online.de/div/setup_usb_lcd.exe (Some examples and so on)

No, i've newer made something runing over i2c (I have only this stupid Nunchuck and now the display).
But if I did understand right you have to send a read-i2c command over usb to get unformation (I thought it would be like rading a eprom or like this)

[Admin]

I'm sorry, but we cannot help you if you don't tell us anything about your setup. We need to know how you wired everything up, what you did, what you programmed, what you tried to do to fix it, and why you think it isn't working.

Judging by your pictures, you entirely wired it up incorrectly. For example, you aren't even using the I2C pins on the Axon, and appear to have two ADC pins spliced to a USB cable going to both your PC and the I2C of the LCD. Your code shows you printing out data to yet a 3rd mysterious USB cable . . .

 

In short, we need a clear wiring diagram.

[PAT_McUser]

The Display don't capture date from the i2c automtically, it need a command from the usb-port. Without the usb command the display doesn't show (or do) anything. Usb works with 4 wires 5volt, Ground, Data+, Data-, I connected the axon ADC to the Data+ and Data-, so i can read all send data. A usb-port sends data with up to 12mhz, the axon has 16 mhz, so if the cpi is higher than 1,33 I can't capture all data send on the wires. (Look the picture, you would see). So the experiment work like this:
1. Conect Axon to usb (of my PC),
2. Start HyperTerminal,
(3. Turn on Axon,)
3.1 Conect Display to usb (of my PC),
4. run a display test (print some strings).
5. wait till end of universe and thats it.

My plan is to build a robot (mobil) with no connection to the Pc (even not the display). I want to send Information to the display (with the axon), so it shows some states or something else.

My Problem is that the data don't reach the display when i contact the axon. The other Problem is to get the sendet data (don't know if it's posibile).

[Admin]

I'm still not entirely sure what you are doing . . .

Correct me if I'm wrong here:
Axon gets sensor data
data then goes from Axon to PC with hyperterminal
then the PC sends data by USB to your display

right? So why do you have two ADC wires connected to the Axon?

If you were trying to send data from the Axon directly to the Display, you need to disconnect the ADC wires completely, and only hook it up between the Axon I2C pins, and the Display I2C pins. You can't use ADC to send I2C, nor can you attach I2C directly to your PC, and I2C can't mix with USB.

[madsci1016]

I think he is just using the Axon to capture the USB data as it goes from his laptop to the screen. (I could be wrong)

Is the Axon fast enough to do this?

[PAT_McUser]

the last post is finaly right i capture the data from PC-to-Display-wire with the axon.
If I have found out how the PC-to-Display data have to lok like, then I can simulate thedata with the axon, but first I have to read the usb signal.
I'm not shure if the axon is fast enounght, that was why I made my cpi calculation, so I nead realy fast software to read and print. I have a new idea for wire up, but I must see when I have a bit time to test. My idear was to go from Pc to Axon (maybe adc (1) and adc (0)) and from axon to display (maybe adc(3) and adc(2)), in this case I can slow down Usb to better readable speed (usb speed is variable, but don't know realy much about this). I think ther is some synchronisation between the two devices and so the speed is correct that allows the axon to get correct data and give them to the other device.
Not sure if it works, but I'll try.
My question is still up to date, how to transver usb data withe the axon to an other device.

[Admin]

The Axon can transmit information *much* faster than your eye can see it on a screen.


PAT_McUser, your posts are someone difficult to read. Please use Windows Word to grammar/spell check what you write. If I misunderstand a question, I won't be able to give you the correct answer

[madsci1016]

The Axon can transmit information *much* faster than your eye can see it on a screen.

But can it read USB data just as fast? This is what he is trying to do.

Seeing as the 'full speed' USB connection is 12Mb/s, and the Axon runs at 16 Mhz, i would guess the Axon cannot sample fast enough to capture USB data.

[Admin]

What baud rate do you need?

[PAT_McUser]

What baud rate do you need?

Don't know.

Maybe there is a other way to do... ...don't know but I cant gues one now... If I get some new informations I'll tell.