Difference between revisions of "AVR Drivers"

===Flashlight Drivers===

===Hardware===

'''[http://www.nongnu.org/avrdude/ AVRDUDE]''' - It is a command line interface (DOS). If you use Tido's programs then you don't need to compile anything: those programs are ready to be loaded. If you install MHV AVR Tools/WinAVR, AVRDUDE will be included. Does not support ATtiny13A, have to use a workaround and pretend it's ATtiny13.

==== USBasp Driver ====

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Communication with the Atmel chip is via Serial Peripheral Interface (SPI, see [http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus Wikipedia article]) with the ISP programmer a Master and the Atmel on the driver board a Slave. SCK is Serial Clock so they are in sync. The ISP programmer talks on the MOSI line (Master Ouput, Slave Input) while the Atmel talks back on the MISO (Master Input, Slave Output) line. RST is reset.

Now everything is installed and set up. You should be able to plug in your USB programmer with the cable leading to the clip. Attach the clip to the Atmel chip right-side up with at least the 5 critical pins wired correctly.

Now open a command window in Windows (or whatever you are in) and typing this command at the C: prompt:

==Download settings==

<PRE style="white-space:normal;">avrdude -p t13 -c usbasp -u -Uflash:r:flash-dump.hex:i -Ueeprom:r:eeprom-dump.hex:i -Ulfuse:r:lfuse-dump.hex:i -Uhfuse:r:hfuse-dump.hex:i</PRE>

==Upload new settings==

Open a command window in one of the BLF-VLD subdirectories: "Fixed Modes", "Programmable", or "Simple". With everything hooked up, enter this command:

The :w: part of the command tells the programmer to <u>w</u>rite settings from the files for flash memory and eeprom and to set the values of the low and high fuses to the hexadecimal values shown. :a is for automatic file type detection, :m indicates "immediate mode" (use the hex values given).

==Compile your own code==

See [[Modifying BLF-VLD]] for programming notes.

=== Optimizations ===

In general:

'''Mode Memory''' Some flashlights will remember the last mode they were in. Often the mode will be remembered after the light is off for a couple of seconds (if it was too short an interval you couldn't change modes by half-pressing the tail clicky to off briefly). But NANJG drivers usually have memory that sets after the light is on for a couple of seconds. When you turn the light off, it will come back on in the last mode, but if the light was on for less than 2 seconds, it will come back on in the next mode. This works pretty well except that if the light is on for a couple of seconds and you want to change modes, you will have to half-press the clicky once and end up in the same memorized mode, and then again to change the mode. The reason for memory to be this way is that when power is cut to the driver, it can't write to its memory. But it is easy for the memory to be written while the light is on and a timer can be used to write to the memory after the light is on for a couple of seconds. In order to get conventional memory, a capacitor would have to be added to hold on to power long enough after the power is turned off for the driver to write to its memory. BLF user sixty545 has done just this, described [http://budgetlightforum.com/node/799?page=3#comment-15453 here].