Sandwich cards must be mounted on a motherboard of some kind to receive power. You can find the position of the mounting holes and the three CF-1 connectors in SCMech.pdf.
This problem may occur when using the latest development tools and running the code on a CF1 with PICODOS and BIOS earlier than 2.27. You can apparently solve the problem by adding a call to VEEInit() to your code before calling any U4S library routines. Apparently the CF-1 patch code that copes with older BIOS versions does not properly initialize the VEEPROM static structures. Updating the BIOS and PICODos to version 2.27 or higher should also correct the problem.
The CF-1 code for reading and writing to hard disks via the BigIDEA card does not use interrupts. However, IDE interface does have an interrupt connection to IRQ 2. This IRQ is used by the disk drive to signal that it is powered up and ready to go. After the drive is ready, the CF-1 driver sends a command to disable the interrupt. However, this first interrupt can cause a problem if the serial port is already set up to accept interrupts.
The simplest solution, if you have only a single UART4 or U4S, is to use IRQ5 for the serial I/O. On newer versions of the BigIDEA, you can disconnect the interrupt by moving a jumper. On older versions, you may need to cut a trace to disable the BigIDEA interrupt.
The AD16S sets up the CF-1 SPI port as a slave and allows the AD974 to provide the SCLK signal. This allows faster data transfers than are possible by using the CF-1 as the master. This increase in speed is a result of two factors:
1) The AD974 can clock the data at a 6MHz rate--while the CF-1 is limited to a 4MHz rate.
2) As a slave, the AD974 requires 18 clocks--and the CF-1 SPI port ends up with misaligned data which must be shifted before transferring it to your program.
The CF-2 uses the SPI serial port to communicate with its real time clock and must have it set up as an SPI master. Adding an AD16S will cause a conflict in the usage of the SPI. If you need 16-bit analog data, you may use the AD16S2 Sandwich Card compatible A/D from OES. This card uses the A/D as a slave and is compatible with the CF-2. However, it is limited to approximately 40K Samples/second and has only the +/-10V input range.
The sandwich cards (U4S and AD16S) are uniquely identified by a product ID and serial number in the PIC Sandwich Card Controller. In order for the software libraries to work properly, the card initialization routines must find an environment variable that exactly matches the data in the PIC. If you swap cards or CF-1s during testing, you must be sure to set up the environment variable to match the peripheral card. Instructions for setting the environment variable are contained in the manual for the Sandwich card.
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