Chang,
You can support many devices on the same SPI bus, provided that you arbitrate the bus so that communication is only taking place with one at a time and you have a spare digital output to use as a chip select line. Arbitration is critical with the radio, since the receiving of messages is performed through interrupts.
The problem that you will run into is that the master-in-slave-out (MISO) line is not routed to the 10-pin or 6-pin header. What I have done to enable SPI with my boards is solder a wire from the MISO pin on the Flash memory chip to pin 4 on the 6-pin connector, since they are very close. Then in software, set P2.6 (the signal that pin 4 is routed to on the board) to GIO as an input so that the MISO line can control the line as it wants to. Since the complete SPI interface is not routed to the IDC header pins, I imagine this is why no examples exist for SPI.
Matt
To: <[email protected]>
From: "Chang Li" <[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
Date: 06/23/2006 11:41AM
Subject: [Tinyos-help] Using SPI with Telosb ConnectorHow to use a SPI device along with telosb's IDC connector? I want to use USART0 pins or I2C pins for SPI link. However SPI0 has been used by CC2420 and Flash Memory, is it possible to connect third device? I found the I2C examples where are the SPI examples? Another way is to share SPI1 with USB chip, unfortunately there is no external connection available.Chang_______________________________________________
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