I2C status on exit:
CALIBRE
See Appendix A for details of the status values returned.
The status of the Parallel I2C Communications Adapter will not be affected by using the FNgetstatus% function.
Example Usage: | (see also sample programs) |
'This will read the Parallel I2C Communications Adapters current status sub main
i2cstatus% = getstatus
print"Parallel I2C Communications Adapter Status = " + hex$(i2cstatus)
end sub
4.3.3.I2C Address and Start Sending Routine
Function definition: | sendaddress(slaveaddress as integer, setnack as integer) |
Usage: | i2cstatus = sendaddress(slaveaddress%, setnack%) |
Function: | procedure to send Start and slave address of device which is to be |
| communicated with. |
Parameters are: | slaveaddress% |
| The slave address of the device which is to be communicated with. This will |
| be an even number if the adapter is to write to the slave, add 1 to get an odd |
| number if the adapter is to read from the slave. |
| setnack% |
| This controls whether the Parallel I2C Communications Adapter transmits an |
| Acknowledge down the I2C Bus on reception of a byte. The last byte received |
| during a transfer must not be acknowledged, in all other cases acknowledge |
| must be enabled. If setnack% = 0 then acknowledge is enabled, if setnack% |
| = 1 then acknowledge is disabled. Therefore, if a read (odd numbered) |
| address is being sent AND only 1 byte is to be read, setnack% should be set |
| to = 1; in all other cases it must be clear = 0. |
Value Returned: | I2cstatus% |
| The value returned depends on whether the Start and address were sent. |
| If the start and address have been sent then the status returned will either be |
| &H00 (bus busy data sent and acknowledged), or 0x08 (bus busy, data sent |
| but not acknowledged). |
| If the start or the address cannot be sent (either the bus remained busy or the |
| address did not get sent) then the last status read IORed with &H8000 will be |
| returned. |
| The function will read the status a number of times before returning an error |
| condition - this number is defined by the MAXNUMBEROFGOES constant |
| defined in I2CINC.BAS, this value may be altered to suit your system. |
I2C status on exit | &H00 bus busy and address sent and acknowledged |
| &H08 bus busy and address sent but not acknowledged |
| &H80 bus busy and address not sent. |
| (see Appendix A for details of Status codes). |
Example Usage: | (see also sample programs) |
' This will send a Start and the I2C Slave Address of the device to be communicated with.
Issue 1.3 | Page 15 |
22/07/99
