Storing value into Orangutan X2 memory

Robotics and electronics discussion Software and microcontrollers
1

Hello,

I work on a robot that avoid obstacles and uses Orangutan X2.
I would like to save two of my float variables (the position x and y) into the memory of the micro-controller every seconds and be able afterward to read these values in order to make a graph on Excel. Should I use the EEPROM ? How can I write my values ? Is it possible to read them directly using AVR Studio ?

If you need more precision i’ll be glad to give them to you.
Thank you for your help

2

Hello Boundal,

I wrote my data to RAM and then dumped the contents to the serial USB connection which I then captured using putty (terminal program). I took the output from putty and pasted it into an Excel spreadsheet.

When it was time to dump the contents, I printed a message on the LCD to prompt me to connect the USB and then waited for a button press before sending to the USB serial.

// val1[] and val2[] hold up to max_log_items values
					clear();
					print("Mid Button Dump");
					wait_for_button_press(MIDDLE_BUTTON);
					clear();
					print("Dumping...");
					char send_buffer[200];
					int idx;
					for (idx = 0; idx < max_log_items; idx++)
					{
						sprintf(send_buffer, "val1:%d val2:%d\r\n", val1[idx], val2[idx]);
						serial_send_blocking(USB_COMM, send_buffer, strlen(send_buffer));
					}
					clear();
					print("Dump Done");
					delay_ms(2000);

Hope this helps,
Mike

3

Thank you Mike. This is exactly what i was looking for.
I would like to know where I can find the serial_send_blocking() function. Is it in some .h file ? What is the USB_COMM value on a Orangutan X2?

Simon

4

Hi Simon,

The function is described in the Pololu AVR Library Command Reference:
pololu.com/docs/0J18

And the Pololu AVR C/C++ Library User’s Guide:
pololu.com/docs/0J20

Not sure which Orangutan X2 you are using but if you click on the resource tab you will find a great deal of information. For example here is the information supplied for the Orangutan X2 with VNH3:
pololu.com/catalog/product/716/resources

Take sometime and read the documents,

Mike

5

Thanks a lot for all these information.
I tried to implement it but run into a lot of conflict since I already use the timers in my project and these same timers are defined somewhere else in the Pololu lib. Since it is a .a file it is not easy to modify it.
That a shame since your solution would have work perfectly

6

Hello.

The source code for the library is included with the download. You should be able to just copy the parts you want into your own program.

- Ben