I have done a lot of work in this area because my projects require flash. Flash memory *is* EEPROM. On your micaz you do have 128kB of ROM memory for your actual binary program on the chip, which you don't have access to. 512kB external flash memory can store data and whatever else you want on, and 4kB of RAM memory for variables/arrays to run your program.
For simple logging, check out http://www.tinyos.net/tinyos-1.x/doc/tutorial/lesson8.html This will append bytes to the flash and allow you to read them back. It sounds like, because you're copying full buffers into flash for temporary storage, you may need something a little different than the logging functionality. It's easier to implement a temporary storage on flash than a permanent storage that is retained after reboot because you don't have to deal with finding the write location after a reboot; instead, you can erase the pages of flash you'll use when the mote boots up and start your app writing at 0x0 each time. The AT45DB flash on a micaz can do page-level erases, meaning you erase 256 (+8 extra bytes/page) each time you want to erase data. When you write to the AT45DB, the data actually goes into a physical RAM buffer on the chip before being stored to flash. That means your data won't actually get written until you flush it to flash. Here's a little background on the way flash writes. The process of writing on the AT45DB is usually a read-modify-write, which is different than standard NOR-flash behavior in that the data from a page is first read into its RAM, the data is modified, the page is erased, and the modified data is written back to flash. This prevents data from being corrupted. Standard NOR-flash behavior is 1's turn into 0's on write, and 0's turn back to 1's on erase. So if you wrote 01101101 to a byte on a NOR-flash (like the STM25P on tmotes) and then wrote a 10010011 to that same byte location, you'd end up with 00000001 - not what you'd expect. The AT45DB's read-modify-write prevents this from happening at the expense of time and energy. If you look at the power consumption plot I attached, you can see this behavior (as well as the required energy!) for a few page writes. The flat line is a read, the squiggly lines are writes. Note that the current gets up to 70 mA - you'll need some good batteries (not coin cell) to supply that kind of instantaneous current. With all that said, you can try the PageEEPROM component to do all that, but I recommend trying out the component I wrote to do kind of what you're doing, found in the TinyOS 1.x CVS under /contrib/rincon/apps/FlashBridge. The FlashBridge component is meant to be a library that you can use in any application to directly access flash. You'll need to download most of that /contrib/rincon directory to get the demo apps working (including /tos/lib/Transceiver, /tos/lib/State, and /tools/java/com/rincon/flashbridgeviewer if you want to read the raw flash onto your computer screen) and you'll need to modify the Makefile to include the AT45DB directory instead of STM25P. To try it out, compile and install the FlashBridge component onto your micaz. Then, you can connect to the micaz using serial forwarder and use the Java FlashBridgeViewer app to interact with the flash and get an idea of its behavior. The readme is provided in the /contrib/rincon/apps/FlashBridge/apps/FlashBridgeViewer directory, and part of it is copied below. If you're working with a buffer of data that needs to be stored on flash, I'd recommend breaking them up into 256-byte segments to make them easy to read/write in page increments. Let's say you only need to store a few buffers of data on flash. On boot, erase the first page of flash (this isn't good for wear-leveling, but you probably won't reboot 100,000+ times either): call FlashBridge.erase(0); This will erase the entire first sector - 256 pages of flash, or 256*256=65536 bytes (~1 second erase time). When you issue a command on flash, wait for the event to come back before issuing another command. Now you can start writing at 0x0: uint8_t buffer[256]; // Here's your buffer of data you want to store to flash uint32_t flashWriteAddress = 0; // the next location to write to on flash void writeToFlash() { call FlashBridge.write(flashWriteAddress, &buffer, sizeof(buffer)); // Write the entire buffer to flash. } // Wait for the event to come back.... event void FlashBridge.writeDone(uint32_t addr, void *buf, uint32_t len, result_t result) { if(result) { // SUCCESS! update our write location to the next page, or something. // Note that if we only erased sector 0 on boot, anything after address 0x10000 (the 257'th page on flash) // may not be valid to write to flashWriteAddress += len; } } The FlashBridge component extends the PageEEPROM component incase you want to try to use the PageEEPROM component directly. Then you can check out how it works in FlashBridge's AT45DB implementation. You'll have to write you own apps to get the data onto and off of flash. Hope that gets you started, -david // readme.txt First let's take a look at what commands we have available from the FlashBridge. Compile FlashBridgeViewerTest or BlackbookConnect or something to the mote and connect to the mote with your serial forwarder. Then... $ flashbridge No arguments found Usage: java com.rincon.flashviewer [mote] [command] COMMANDS -read [start address] [range] -write [start address] [22 characters] -erase [sector] -flush -crc [start address] [range] -ping Let's ping the mote to see if we have FlashBridgeViewer installed: $ flashbridge -ping Pong! The mote has FlashViewer installed. Great, now let's read a page of data: $ flashbridge -read 0 0x100 0x0 to 0x100 _________________________________________________ FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | Let's write some data. The FlashBridge itself lets you write as much data at a time as you want, but our TOS_Msg's being passed back and forth over UART only hold so much. And there's not much you can specify on the command line anyway, so here's what happens: $ flashbridge -write 0x0 hello_flashbridge! Writing data 0x68 0x65 0x6c 0x6c 0x6f 0x5f 0x66 0x6c 0x61 0x73 0x68 0x62 0x72 0x69 0x64 0x67 0x65 0x21 SUCCESS: 18 bytes written to 0x0 We'll read 0x20 bytes back from 0x0 to make sure what we wrote exists: $ flashbridge -read 0 0x20 0x0 to 0x20 _________________________________________________ 68 65 6C 6C 6F 5F 66 6C 61 73 68 62 72 69 64 67 | hello_fl ashbridge 65 21 FF FF FF FF FF FF FF FF FF FF FF FF FF FF | ! Keep in mind that the AT45DB flash doesn't necessarily put what you wrote onto the physical flash until you flush it out, so here's how you flush: $ flashbridge -flush SUCCESS: Flush complete We can take the CRC of the data we just wrote: $ flashbridge -crc 0x0 18 SUCCESS: CRC is 0x6D3F And we can erase the entire sector. FlashBridge was designed for sector erases, which you can actually go in and edit if you want - but it's not entirely recommended. The ST M25P80 flash erases in sector-lengths, which is 64kB at a time. Atmel's AT45DB flash chip erases in page-lengths, which is 256B at a time. To maintain compatibility between the two chips, FlashBridge erases the full 64kB at a time on both the AT45DB and the STM25P chips. It can probably be done faster on the AT45DB implementation than it is right now, but I haven't programmed any of the block erase stuff that the chip actually supports. Another option would be to go in and edit the FlashSettings.h file for the AT45DB and define smaller sector sizes and readjust all those flash parameters, and that should maintain compatibility as well. So let's erase. It takes about 1 second/sector - which is 1 second per erase. $ flashbridge -erase 0 SUCCESS: Sector 0 erase complete And for that AT45DB you'll want to flush after that as well to make sure changes are commmited to flash. Now let's read back address 0x0: $ flashbridge -read 0 0x100 0x0 to 0x100 _________________________________________________ FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | -----Original Message----- From: Munaretto, Daniel [mailto:[EMAIL PROTECTED] Sent: Tuesday, August 01, 2006 11:46 PM To: [EMAIL PROTECTED] Cc: tinyos-help@Millennium.Berkeley.EDU Subject: for David Moss: [Tinyos-help] Help with real node behaviour!Micaz,tinyos 1.x -----Original Message----- From: Michael Schippling [mailto:[EMAIL PROTECTED] Sent: Tue 8/1/2006 7:19 PM To: Munaretto, Daniel Cc: tinyos-help@Millennium.Berkeley.EDU Subject: Re: [Tinyos-help] Help with real node behaviour!Micaz,tinyos 1.x I haven't used the FLASH so I can't give good advice. David Moss on this list seems to know a lot about it, perhaps he will answer? MS Munaretto, Daniel wrote: > Hi Michael, > The problem is that we need more memory for our project. Even if FLASH memory is slow, i think we need to use all possibilties that micaz mote gives to us. Is it possible to use it for writing data? (i know that for ADC readings it is used, and just to remember we use tinyos 1.x and micaz motes, Atmel ATMEGA128) > if yes, how?and how much? and what about relative energy consumption and time requested? it would be really useful...any informations will be really appreciated! > Because we can think to solve this memory problem by using RAM and FLASH together: sometimes, when we receive packets for bufferizing, we can move this buffer from RAM to FLASH memory temporary or viceversa, i don't know exactly how i should manage this situation. But what i mean is something similar to PC hard-disk.... > > cheers > Daniele > > -----Original Message----- > From: Michael Schippling [mailto:[EMAIL PROTECTED] > Sent: Mon 7/31/2006 9:12 PM > To: Munaretto, Daniel > Cc: tinyos-help@Millennium.Berkeley.EDU > Subject: Re: [Tinyos-help] Help with real node behaviour!Micaz,tinyos 1.x > > > > As far as I know all of the 4k of RAM is available for use, > so you should have about 2.5k for your buffer allocs. Maybe > you can put in an allocation size detector for your simulation > so you can see where it (is assumed to) overflow? Or log all > the alloc/frees and match them up... > > MS > > Munaretto, Daniel wrote: > > Thanks for your answer, in my program i allocate memory to create in each mote a buffer-chain (i use structures that allocate memory dynamically). But i don't know exactly how much dynamic memory i can use in Micaz motes. > > > For example, if after compiling i use 1419 bytes in RAM and 19748 bytes in ROM, is the rest used for dynamic allocation? > > > i don't understand this passage about exactly how much memory i can use dynamically..for me understanding would be really important. > > > Thanks for your availability, > > > > Cheers > > Daniele > > > > -----Original Message----- > > From: Michael Schippling [mailto:[EMAIL PROTECTED] > > Sent: Fri 7/28/2006 7:12 PM > > To: Munaretto, Daniel > > Cc: tinyos-help@Millennium.Berkeley.EDU > > Subject: Re: [Tinyos-help] Help with real node behaviour!Micaz,tinyos 1.x > > > > > > > > Well there's 128K of PROM and 4K of RAM in the ATMEGA 128 > > and I believe it is all available. At the end of the TOS > > compile you get a line that says how much your program is > > using. If you are not doing any kind of dynamic allocation > > this should be the maximum used. Perhaps you have a pointer > > or something that is running amuck in a way that you don't > > see in simulation. > > > > I think using FLASH is rather slow and the number of MTBF > > cycles is not conducive to temporary storage. > > > > MS > > > > Munaretto, Daniel wrote: > > > I did other experiments and i found that, with little data size, the nodes are able to send and receive all packets they generate. So it's definitely a memory problem. But i think not to use so much memory and i free, when i can, the used structures. Remember i need a buffer chain in each node cause i store incoming packets and then i create new coded packets from these buffers. > > > > Now my question is: with Micaz motes, tinyos 1.x, how much memory in ROM and RAM can i use? > > > and is it possible to use the FLASH memory?if yes how?and what's the size of it? > > > If possible, i'd like to receive very precise informations for understanding my problem in the best way. > > > > > > Thanks very much for your availability > > > cheers > > > Daniele > > > > > > -----Original Message----- > > > From: Michael Schippling [mailto:[EMAIL PROTECTED] > > > Sent: Thu 7/27/2006 9:25 PM > > > To: Munaretto, Daniel > > > Cc: tinyos-help@Millennium.Berkeley.EDU > > > Subject: Re: [Tinyos-help] Help with real node behaviour!Micaz,tinyos 1.x > > > > > > > > > > > > Sounds like your buffering scheme is overflowing and crashing the mote. > > > One clue is that I seem to see a lot of length 5 buffer pools in TOS... > > > You might want to double check that you are freeing buffers after use. > > > MS > > > > > > Munaretto, Daniel wrote: > > > > Hi all, > > > > after a lot of simulation in TOSSIM, i uploaded my programs on the motes. > > > > By reading the leds, i'm able to understand what happens. > > > > > > > > If i run on motes a normal flooding, it's all ok. All packets are sent and received. > > > > > > > > But if i run a more complex program, where before broadcasting packets i code packets i stored in the node's internal buffer, i notice i cannot receive over 5 packets (in my experiments i generate 8 packets per node). But if i run only one mote, it's able to generate all packets. > > > > > > > > So if i run 2 nodes, one seems blocked or crashed after receiving 5 packets (Leds stop to work, fixed on a color or void) and the other one continue to send packets in a properly way. > > > > > > > > I made with several motes and it's the same, also changing batteries. > > > > > > > > Anyone could help me, please? > > > > i don't know what's wrong, in TOSSIM was all ok. > > > > And i'm using micaz motes, tinyos 1.x, after compiling i see: used RAM=1657 bytes, used ROM=19600 bytes. > > > > > > > > > Thanks very much, i hope someone could answer to me! > > > > cheers > > > > Daniele > > > > > > > > > > > > _______________________________________________ > > > > Tinyos-help mailing list > > > > Tinyos-help@Millennium.Berkeley.EDU > > > > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > > > > > >
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