Hi Darren, For the throughput, there are a couple of things that could be influencing this. The size of the packets that you are passing to the bluetooth module, the baud rate that you are using to communicate between the MSP430 on the Shimmer and the BT module, the performance of your receiving PC, etc. As a first step to increase throughput I'd at least double the baud rate (you can try higher, but I'm not sure how well the MSP will handle this) as this is a known bottleneck and use larger packets (it might take some experimentation to find the ideal packet size as a lot of factors can influence this). Just as an aside, be careful changing the baudrate on the BT module as a number of people have managed to change the baud rate to a random value and then could no longer communicate with the module. If this does happen see the instructions below this that I recently sent to somebody to rectify this.
Re. your SD read problem: if you can write to the card you should be able to read from it without any problem. Are you sure you are reading from the correct address, that the correct file is opened, the buffer that you are reading the data into is large enough, ...? It's a bit difficult to diagnose this problem with the limited info you have provided. Mike > > The Bluetooth module has a feature, namely remote configuration, that can > be used to allow you to reset the baudrate. See the Bluetooth module's user > manual for more details about this feature: > http://www.rovingnetworks.com/resources/download/47/Advanced_User_Manual > > See the following instructions for how to change the buad rate using this > feature: > > 1. Make sure firmware that enables the BT radio, but does not > immediately disable the remote configuration feature immediately (as > BoilerPlate does), is loaded on the Shimmer > 2. Connect to the shimmer with a terminal emulator. For the following > instructions I’m going to use HyperTerminal in windows XP, but any should > do. > 3. In HyperTerminal turn on the “Echo typed characters locally” feature > (to make life easier), in File->Properties->Settings->ASCII Setup… > 4. Disconnect HyperTerminal (but do not close it). > 5. Press the reset button on the Shimmer > 6. Reconnect to the Shimmer immediately with hyperterminal > 7. Type “$$$” into the terminal window (without the quotation marks). > The remote configuration feature is only enabled (by default) for 60 > seconds after the BT module powers up, so you have to send the command > within this time frame. If successful you should see “CMD” appear in the > window. This step can be tricky at times. While these instructions mention > using Hyperterminal, I have had better, more consistent, results at this > step using terminal emulators in Linux, such as minicom or cu. > 8. For the rest of these instructions anything within quotation marks > should be typed into the terminal window, but without the quotation marks. > 9. Type “D” and press return. This is just to confirm that the commands > are working as expected. You should see the BT modules basic settings. > Something like: > > ***Settings*** > BTA=00A09628E03B > BTName=FireFly-E03B > Baudrt=230K > Parity=None > Mode =Slav > Authen=0 > Encryp=0 > PinCod=1234 > Bonded=0 > Rem=000666422418 > > 10. Type “SF,1” and press return. This resets the module to the factory > defaults. You should see "AOK" returned > 11. Type “---“ and press return. You should see END. > 12. Disconnect Hyperterminal and reset the shimmer. It should now be > back to normal On Wed, Aug 29, 2012 at 11:22 AM, Darren Craven <[email protected]>wrote: > I have two questions I want to ask in relation to the SHIMMER. > > > Firstly in relation to the maximum throughput of data over the Bluetooth > radio, to test this I have set up the Shimmer to constantly call the > Bluetooth.write() function and am using modified code from simpleAccel.py > to monitor the throughput (using time.time() phyton calls after bytes are > received). I am noticing that even with a looping continuous write call > (Shimmer code doing nothing else) the maximum throughput I am achieving is > generally around the 10KB/s mark. I would have thought I would be able to > achieve much higher, any thoughts on how I would go about increasing this? > > > Secondly I am also trying to incorporate the Bluetooth functionality into > the JustFATLogging application. However the modification I am adding is I > want the to perform read operations on the SD card after the writes have > taken place and then stream those values. I have successfully added in the > Bluetooth functionality. However I have tried adding in FatFs.read() calls > but this operation never seems to be carried out, is there some code I need > to add to ensure the SD card can be read from or anything else I need to do > for this? > > > Any help with this would be appreciated, thanks, > > > Darren > > _______________________________________________ > Shimmer-users mailing list > [email protected] > https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users > >
_______________________________________________ Shimmer-users mailing list [email protected] https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
