[En-Nut-Discussion] nut/os and own design hardware
Uwe Bonnes
bon at elektron.ikp.physik.tu-darmstadt.de
Sat Nov 15 14:48:51 CET 2008
>>>>> "Ole" == Ole Reinhardt <ole.reinhardt at embedded-it.de> writes:
Ole> Hi!
>> I have made my own board with AT90CAN128 and some Bluetooth module on
>> it. Bluetooth is connected to UART1 and I also need to use CAN
>> controller build inside MCU. Because of BT module I need to run this
>> HW with 3.3V VCC and max 8.00MHz clock. There is no extra SRAM on my
>> board... =( [...] What you think, is it possible do those things
>> with Nut/OS and without extra SRAM? First one I guest yes but second
>> one may be difficult, even impossible?
Ole> Indeed it _is_ possible to run NutOS on such a limitated system,
Ole> but without much usage for you. You will be able to run a single,
Ole> perhaps two threads with very limited stack size and not much
Ole> possebility to allocate any extra heap space. The AT90CAN128 has
Ole> about 4K of ram, which is very small for a NutOS system. If you
Ole> plan to use the networking layer you even won't be able to run you
Ole> system without any external ram. Just a single Ethernet packet may
Ole> be up to 1.5k large.
>> Also how I make config file for my board to use with Nut/OS Configure
>> Tool? Haven't find any document about config file structure and
>> commands to use.
Ole> Just start Nutconf and start with the ethernut 1.3f config file for
Ole> example. Next change the cpu type, disable networking and other
Ole> drivers you don't need, disable external ram usage and save the
Ole> resulting file as you own config file.
I use NUT-OS on an AT90CAN128 without external ram to build CAN bus
controlled power supplies.
But if space allows, anybody should add external RAM to their boards. It
makes life much esier...
--
Uwe Bonnes bon at elektron.ikp.physik.tu-darmstadt.de
Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
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