Hi Nick,
The code seems logical and fine. Can you use the inquiry command to check what the channel contents are for the data packet being sent by the Shimmer unit, it might give a clue as to what might be going on. JC _____ From: [email protected] [mailto:[email protected]] On Behalf Of Nicholas Hosein Sent: 15 May 2012 21:25 To: Jong Chern Lim Cc: [email protected] Subject: Re: [Shimmer-users] EMG Packet Question *And by correctly i mean it sends 6 bytes of emg data which seems wrong since it should be 2 bytes. -Nick On Tue, May 15, 2012 at 1:21 PM, Nicholas Hosein <[email protected]> wrote: Hi Jong, This is the C++ code that ive been using. It works for acc/gyr/mag. Now i am testing it on emg: char arg0 = SET_SENSORS_COMMAND; char arg1 = (acc << 7)+(gyr << 6)+(mag << 5) +(ecg << 4)+(emg << 3)+(gsr << 2) +(ex7 << 1)+(ex0 << 0); char arg2 = 0; socket->write(&arg0,1); socket->write(&arg1,1); socket->write(&arg2,1); For the EMG Shimmer Mote when i have all sensors off except the emg (acc disabled) I get the situation in my previous email with a packet size of 9 bytes including header and timestamp. I do receive an ack from the shimmer mote after sending the command. When i request to start the collection of data the data comes correctly at the frequency i specify. Much Thanks, Nick On Tue, May 15, 2012 at 12:22 AM, Jong Chern Lim <[email protected]> wrote: Hi Nicholas, Could you explain a little more about what you mean by 'sent the signal to enable the acc'? As an example using java (assuming you are using the standard serial protocol), the transmitted packet should look something like write(new byte[]{0x08, 0x08, 0x00}); If you refer to http://tinyos.cvs.sourceforge.net/viewvc/tinyos/tinyos-2.x-contrib/shimmer/a pps/BoilerPlate/Shimmer.h?content-type=text%2Fplain , you will see that the first 0x08 is the packet type: Set_Sensors_Command and the second 0x08 is SENSOR_EMG. Were you able to receive an Ack packet after sending the set sensor command packet? Regards, JC _____ From: [email protected] [mailto:[email protected]] On Behalf Of Nicholas Hosein Sent: 14 May 2012 23:16 To: [email protected] Subject: Re: [Shimmer-users] EMG Packet Question In addition the data doesnt seem to change with stimulus from the muscle. On Thu, May 10, 2012 at 2:09 PM, Nicholas Hosein < <mailto:[email protected]> [email protected]> wrote: So i currently have acc/gyr/mag working and was adding emg support to my C++ program. I sent the signal to enable the acc/emg (bit3 = 1 ). I then receive 9 bytes from the shimmer = 1 header, 2 timestamp, 6 data. My question is why does the emg have 6 bytes of data? The accelerometer has x,y,z so 6 bytes makes sense but the emg is just one signal? Thanks, Nick
_______________________________________________ Shimmer-users mailing list [email protected] https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
