Using the external I2C master:
UM0300
18/22
3
Using the external I
2
C master:
We can also use an external I
2
C Master by using pins available on J1 connector as shown in
the
, below:
Figure 24.
External I
2
C connector
To control the STMPE2401 devices using the external masters, do the following steps:
1.
Set the demo board to run mode as explained earlier.
2. Remove
the
I
2
C connections from jumper JP1 and JP2. This is required to avoid any
conflict due to I
2
C operations done by the demo itself.
3.
Connect the SCL and SDA lines available in jumper J1.
4.
For controlling the Interrupt line, use PA4 for INT1 (Slave1 interrupt line) and use PA5
for INT2 (Slave 2 interrupt line),
5.
After you have done the required operations, remove all the connections as mentioned
in steps 2, 3 and 4. Now connect the make the I
2
C connections Jumper JP1 and JP2
again.
6.
Reconnect the RESET button on the demo board to put demo back in action.
In this mode, PC GUI will not be available for the external user to use. Again you have to use
the slave address as specified in the demo which is 0 x 84 for Slave1 and 0x86 for Slave2.
Again this I
2
C lines are working at 5 V power supply so external I
2
C Master should use 5 V
power supply.