Hi all - I'm playing around with an attempt to do some serial communication from within R to a microcontroller board. I open a connection:
zz = file("/dev/ttyUSB0",open="a+") ## text mode ... when I execute writeLines("0",con=zz) I know the board receives the "0" because the board's serial comm LEDs light up when submit the command at the R prompt. However, if I want to open the connection to the board in binary mode: zz = file("/dev/ttyUSB0",open="a+b") ## binary mode ...submitting writeBin(as.integer(9), con=zz, size=1) doesn't do anything (no serial comm LEDs active) until AFTER I run a readBin(zz,"integer") I know the data arrives at the board correctly, because if the board receives the right byte over the serial connection, it's been programmed to light a particular LED. The problem is, the LED doesn't light after the writeBin command, as one would expect, but only after the subsequent readBin command has been issued. As I said, the text mode behaves as expected, with communication occurring after the writeLines command, but there seems to be something wrong with the way writeBin is working (or at least the way I'm using it!). Any pointers would be greatly appreciated! Jake > sessionInfo() R version 2.6.1 (2007-11-26) i686-pc-linux-gnu locale: LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=en_US.UTF-8;LC_MONETARY=en_US.UTF-8;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] lars_0.9-7 randomForest_4.5-22 RBGL_1.14.0 [4] graph_1.16.1 cairoDevice_2.5 loaded via a namespace (and not attached): [1] cluster_1.11.9 rcompgen_0.1-17 tools_2.6.1 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.