I am new to the Rabbit 2000 micro and the BL2100. I have the BL2100 w/ ethernet and analog I/O options.
I would like to connect an external SPI or I2C device. Does anyone have suggestions on what I/O pins to try? Any software routines for the external SPI or I2C? External interrupt connection?
The device I’m looking to connect is a Microchip MCP2515 standalone CAN spi interface chip.
Normally I would get a micro with built in CAN support, but I already have the BL2100 and this seems like a worth while project.
Unfortunately, this is a difficult combination on this particular board. The Rabbit 2000 processor only has two ports capable of clocked serial. Port A which is used as the main download and debug port, and Port B. Although port B is available through RS-232 tranceivers on the board, it is not available directly (TTL levels) without some cuts and jumps. To make matters worse, the synchronous clock line for port B is used by the 2100 board as the data in line from the ADC. It seems you would have a hard time either way in using either of the synchronous ports. You could always bit bang the SPI on other pins, but this may not be desirable if you’re trying to talk to CAN devices.
[QUOTE=JMA_1;45]Greetings,
I am new to the Rabbit 2000 micro and the BL2100. I have the BL2100 w/ ethernet and analog I/O options.
I would like to connect an external SPI or I2C device. Does anyone have suggestions on what I/O pins to try? Any software routines for the external SPI or I2C? External interrupt connection?
The device I’m looking to connect is a Microchip MCP2515 standalone CAN spi interface chip.
Normally I would get a micro with built in CAN support, but I already have the BL2100 and this seems like a worth while project.
Do you have any information concerning the use of the MCP2515 using a RCM3000 or RCM4000 (both preferably). I have a demo board of each and would like to get a rabbit on my CAN bus systems which I have designed for my work.
Unfortunately I have not used the 3000 or 4000 processors.
There is mention of all four SPI modes in the 4000 user manual, pg 129. The C 10 (?) version of the compiler has built in library routines for SPI & I2C -> SPIinit, SPIRead, SPIWrite, SPIWrRd, etc. If you have the development boards you could probably setup a quick test of the SPI and monitor the signals with an o-scope using the library routines.
I remember the Circuit Cellar magazine doing articles on both of the processors. Perhaps they also had sample code in the articles which might be a good starting point.