Why Program runs only when USB attached?-(Solved)

msiriwardena

I have a program in a Propeller Proto board that only runs with USB cable attached but
after it starts working I can detach the USB cable it continues to run but if I power down
and re-starts it will not work until I attach the USB cable, and I don't have to do anything
the program starts to work. The program is in the EEPROM.
In other words I always have to get the program working before I could move the set up.

This is the Transmission board for the Activity Bot.
I have public link to the program also.
Attach is the screen shot of the program.

I like the program to run without the jump start.

Thank you.

Siri

Publison

How are you powering your Proto Board? It will take more power with the XBEE attached.

Picture would help.

msiriwardena

@Publison
At the moment I am powering with 7.7V via a brick 700mA .

Finally I will power with a 5x1.5 battery pack.
I have only 5 way switch, XBee S2C and a LED to indicate Transmission.
The program runs on its own after the jump start with no USB.

Siri

Publison

Are you using the "Down Arrow" to load and save to EEPROM from Blockly?

msiriwardena

@Publison

Since you ? the power supply I tried wih a
7.5V 12Watt power supply and the issue remains.

Siri

msiriwardena

@Publison

Yes I am using the "down arrow" to the EEPROM and not to the RAM.

I have attached a picture of the setup.

Siri

Publison

The line "if Button Press = 31" may interfere with the USB interface as that is a programming port. Change that to a lower pin and see what happens.

Publison

msiriwardena wrote: »

@Publison

Yes I am using the "down arrow" to the EEPROM and not to the RAM.

I have attached a picture of the setup.

Siri

I can't quite see where the pushbutton is attached to. Which Pin? Picture of the bottom of the board please.

msiriwardena

@Publison

Here is the back of the board.

Siri

Publison

Looks like button is connected to 21 not 31?

Phil Pilgrim (PhiPi)

Add a pull-up resistor to Vdd (~2.2K) to your Tx line (P30), and I think the problem will go away. What's happening is that the Propeller is parasitically powering the USB chip when Tx raises, which causes the USB chip to reset the Prop in an endless cycle. The pull-up will keep the USB chip powered all the time, eliminating the edges that cause the reset.

-Phil

msiriwardena

@Publison

The button is connected to pins 18 ..22.


Siri

Publison

I'll have to ask again. Is the line "if Button Press = 31" correct. That is the pin for the communications port, (USB). Should that be 21?

msiriwardena

@Publison

The "if Button Press = 31" is the decimal interpretation of the "center position" of the 5 position switch.
Yes it happens to be the number of the communication pin. There has nothing connected to that pin.
Just using the number 31 should not have any effect.

Siri

msiriwardena

@"Phil Pilgrim"

I will try your solution tomorrow morning.

Thanks for the help

Siri

Cluso99

As Phil said, the problem is with the propellr powering the usb chip form its serial pins. This is a well known problem.

You can try in your code making sure you dont use the serial pins (P30 & P31) and make them inputs.

msiriwardena

@"Phil Pilgrim (PhiPi)" ,@Cluso99

Thank you for rational explanation and the fix worked
as you expected.

Regards,

Siri

Publison

msiriwardena wrote: »

@Publison

The "if Button Press = 31" is the decimal interpretation of the "center position" of the 5 position switch.
Yes it happens to be the number of the communication pin. There has nothing connected to that pin.
Just using the number 31 should not have any effect.

Siri

Glad you go it worked out. I have to say I have not spent enough time in Blockly to realize that it was looking for a value instead of a pin number. I apologize.