tedor

I am receiving data from a bluetooth device.

With the provided patches (in Quartz Composer) I receive the data in hex, where only the first two channels are useful:

-----------------------------------------------------------------

000 is 0V input. -> -2.5 V AD input ( - 100 micro V brain wave input )

200 is 2.5V input. -> 0 V AD input( 0 micro V brain wave input )

3ff is 5V input. -> +2.5 V AD input ( + 100 micro V brain wave input )

10 bit mean 1024 resolution from +-100 micro V brain wave input. ( 200 micro V full scale )

1 resolution is 0.1953125 0 micro V ( 200 micro V / 1024 )

CH3 and CH4 is not connect. (-2.5V connection that inside IBVA hardware )

What I receive in Max/Msp with the serial object looks like this:

Why couldn't I receive the same sort of data? Why is the received data in integers in Max and why is it in hex in Quartz Composer and in the manual which comes with the device?

As far as I am concerned: In max, one line (4 integers) should represent on hex number >

How could I get a hex number out of one line if my presumptions are right?

If anyone could give me a tip!
I am receiving data from a bluetooth device. 

With the provided patches (in Quartz Composer) I receive the data in hex, where only the first two channels are useful: 

-----------------------------------------------------------------
raw data format is :

CH1 , CH2, CH3, CH4 is data order.
each data is 10 bit : 000 .. 3ff (hex)

000 is 0V input. ->  -2.5 V AD input ( - 100 micro V brain wave input )
200 is 2.5V input. -> 0 V AD input( 0 micro V brain wave input )
3ff is 5V input. -> +2.5 V AD input ( + 100 micro V brain wave input )

10 bit mean 1024 resolution from +-100 micro V brain wave input. ( 200 micro V full scale )
1 resolution is 0.1953125 0 micro V ( 200 micro V / 1024 )

--------------
only CH1 and CH2 ( left and right ) use.
CH3 and CH4 is not connect. (-2.5V connection that inside IBVA hardware )

221     18f     003     002
222     121     002     002
1b8     0f6     002     002
181     0b3     002     002
1ad     0fb     002     002
1de     144     002     002
20f     187     002     002
239     1ea     002     002 

Ch1 = 49 101 101 9
Ch2 = 49 102 49 9
Ch3 = 49 48 59 9
Ch4 = 48 48 50 13

serial-port-issue

connect an atoi object after the serial object and you'll get what you want. Note that "13" = carriage return, and "9" = tab. To get all your numbers to come out as a list, send the output of atoi to a "zl group", then when you receive a "13", bang the "zl group" to get your data as a list. Here's a little example.

I had a look at the sample! GREAT! I own you a pint at least:)

1, I am wondering whether there is an easier way to separate the string into the 4 groups, mine looks very ugly.

2, I also will be trying to use the "select 13" object to make sure the data in the groups are always the same.

http://tedor2.extra.hu/mix/max raw to hex.jpg

1, I am wondering whether there is an easier way to separate the string into the 4 groups, mine looks very ugly. 

2, I also will be trying to use the "select 13" object to make sure the data in the groups are always the same. 

> 1, I am wondering whether there is an easier way to separate the string into the 4 groups, mine looks very ugly.

Not too sure I understand what you are trying to do here. What is the purpose of the "zl lookup" here?

Here's a patch with a bit more comments. Plus I was a bit hasty in the last patch and had the "itoa" object too early...well...it still works but you need to add a "fromsymbol" after the itoa. See if this helps any better:

Couple other things to note. I'm using "zl nth" to divvy up the list of the 4 values vs. unpack since unpack gets a bit confused with hex (am I an int or am I a symbol?...zl nth doesn't care). Also, since you are merely polling for data waiting at the serial port, I would change your metro 1000 to metro 10 or even 1, and use "qmetro 1" ("metro 1 @defer 1") so you can poll quickly, but it doesn't get in the way of other more time-sensitive activities in your patch. That way you'll get your data with minimal latency.

Let me know if you still have questions, but you might want to poke around a bit on the forum to see how others have dealt with data coming out of the serial object. There's quite a bit of very useful information here.

> I think I could manage, somehow:
>
> http://tedor2.extra.hu/mix/max raw to hex.jpg
>
> and Attached patch: serialworks.maxpat
>
> 1, I am wondering whether there is an easier way to separate the string into the 4 groups, mine looks very ugly. 

> Not too sure I understand what you are trying to do here. What is the purpose of the "zl lookup" here? <

I have to set the chunk message to 16 and send it to the "serial object", than I use the "zl lookup" to get the 4 groups separated. Well, yours is more advanced. I did not know the "fromsymbol" before, very useful.

I was looking for some answers for my question on the forum but, no luck.

I would like to send a message to the device from Max/Msp whereby I would change the sampling rate of the hardware and also a filter. Well I have got something from the manufacturer, but id I just sent the code in a message to the serial object, I received an error in the post window.

===================================================

other command to set and control hardware sampling rate and set filter frequency.

set filter high cut off frequency ratio )

120 Hz X 0.3333 = 40 Hz : cut off F at -3bd )

Well, do you have an idea, how to send these messages to the device?

I have to set the chunk message to 16 and send it to the "serial object", than I use the "zl lookup" to get the 4 groups separated. Well, yours is more advanced. I did not know the "fromsymbol" before, very useful. 

I was looking for some answers for my question on the forum but, no luck. 

I would like to send a message to the device from Max/Msp whereby I would change the sampling rate of the hardware and also a filter. Well I have got something from the manufacturer, but id I just sent the code in a message to the serial object, I received an error in the post window. 

===================================================
other command to set and control hardware sampling rate and set filter frequency.
===================================================
SR n

　:
1ad     0fb     0d2     0b9
1de     144     11e     10c
sr 120
20f     187     15f     14f
239     1ea     186     1f4
　:
----
===================================================
FR n
n : 0.1000 .. 1.0000

 ( in case sampling frequency is 120 Hz, 
120 Hz X 0.3333 = 40 Hz : cut off F at -3bd )

　:
1ad     0fb     0d2     0b9
1de     144     11e     10c
fr 0.37
20f     187     15f     14f
239     1ea     186     1f4
　:
---------
===================================================

I have to change the hex back to integers now so the modem can understand it, I guess... :)

Yup. serial object receives ints only, and spits out ints only.

Communications tutorial #2 is your friend.

And again, the forum is your friend, too...this question has come up several times before.

Yup. serial object receives ints only, and spits out ints only.
Serial help is your friend.
Communications tutorial #2 is your friend.
And again, the forum is your friend, too...this question has come up several times before.

Right. The issue was, I sent a wrong message.

Works, and the tutorial helped me also to understand more of the serial communication.

Right. The issue was, I sent a wrong message. 

Works, and the tutorial helped me also to understand more of the serial communication. 

Serial port issue