renesto's blog

A lot of engineers in one point of another needs to look through usually undocumented open source code, in order to modify/implement additional features. Using editor for bigger projects built in C/C++ (without OOP) can be unbelievably painful (my own experience). Two software that helped me a lot to reverse engineer my any source code are: 1) Doxygen : Creates nice documentation of all the functions in the project. It gives links to definition of each function, but more interesting is also can create call/caller graphs (for each function it gives graph of functions which it calls, and another graph of the function which call that function). It is completely a freeware, and the graphs are done using the dot program. 2) Understand : the free trial version of this application (14 days) is very handy, and is a bit more powerful comparing to Doxygen.

There are a lot of text editors that offer regular expression search and replace, but rare are those that support multiline regular expressions. In my case I need to find all the function headers with starting body bracket. example: "int a(int b, int c) {" should be changed with "int a(int b, int c) { printf("Entered function a");" Text editor that supports such thing is called "EditPad Pro". Besides multiline regular expression support, it also have coloring system for your regular expression, so u can debug your regex easier. To be edited with regular expressions that solved my problem

http://www.eecs.iu-bremen.de/wiki/index.php/TinyOS

Changing the Radio channel - Radio channel numbers have range between 11 to 26 - Add the following line in the Makefile before the Makerules CC2420_CHANNEL=x where x = [11 26] Changing the Radio Transmit power - Transmit power valid levels are 1 to 31 with power 1 equals to -25dBm and 31 equals to max (0dBm) - add the following line in the Makefile before the Makerules CFlags = -DCC2420_DEF_RFPower= x where x = [1 31] Changing the Active message group ID Add DEFAULT_LOCAL_GROUP = X to the makefile where X = [0×10 0×50]

There are two ways to represent float in nesc. One way, is to do it through by convention using the exponent and mantissa, where you need to use 2^exponent. The function that does that is called powf(). The problem with using that function is that it is reaaaaallly slow. [QUOTE] ----8 DbgOut_P20_ON; r = logf((float)v / 10000.0); // takes up about 10 ms (!!) DbgOut_P20_OFF; ----8 and a ----8 DbgOut_P20_ON; r = powf (10,(float)v / 10000.0); // takes up about 32 ms (!!!!!!) DbgOut_P20_OFF; ----8 [/QUOTE] In case you need to have fast response, this function might not be your choice. One way to optimize the speed of those operations are: "I'd like to mention that pow (a,b) is MUCH harder to implement than exp(b). Use the latter whenever possible. In particular, if a is fixed, use exp(b * log(a)) rather than pow (a,b). ( In fact, that's a common low-precision implementation technique even when a is not fixed.) Also note that keeping ...

Several times I badly needed the connection between to PCs and I never actually managed to make it working :( One thing I always forget to set is that both PCs have the same Workgroup, besides the part where you set your folder to be shared among PCs in the network.

TinyOS 2.x A message sent through serial ports from motes to PC will typically look like this: 00 FF FF 00 00 08 00 09 19 77 02 07 00 13 00 00 The first byte 00 is the leading zero. After that, the whole packet is of the type " serial_packet_t ", defined in tinyos-2.x/tos/lib/serial/Serial.h . Inside the serial_packet_t structure, the first 7 bytes are of the type " serial_header_t" , which is also defined in tinyos-2.x/tos/lib/serial/Serial.h . In the case above, it would be FF FF 00 00 08 00 09 . Within the "serial_header_t", the following structure takes place: nx_am_addr_t dest // Destination (2 bytes) nx_am_addr_t src // Source (2 bytes) nx_uint8_t length // Payload Length (1 byte) nx_am_group_t group // Group ID (1 byte) nx_am_id_t type // Active Message Handler Type (1 byte), some enum value that you can def...