Second serial port for CC1000
Last updated: March 29, 2008
The J802 connector has some usefull signals, including the SMCTX2 (PA-8) and
SMCRX2 (PA-9) signals.
Connecting a RS232 level convertor (MAX232, MAX202 etc.) gives the board a
second serial port.
![[cc1000_serial2.png]](cc1000_serial2.png)
See the CC1000 Hardware description for
J802 pin numbers.
Remarks:
- To get +/- 10V signals from the RS232 level convertor, the convertor must
be powered with 5V. The MPC823 ports cannot handle 5V signals, so the Tx signal
from the convertor is divided down to approx. 3V with resistors. The Rx input
works fine with a 3V signal.
- Although specified for 5V supply, most MAX202 or MAX232 chips seem
to work at 3.3V. The RS232 voltage levels will be approx. +/- 6V.
If this is acceptable there is not need for the voltage divider.
- SMCTX2 is connected to U801-8, U801-5 is connected to J802-17. If you want
to use J802 for all connections U801-5 must be connected to U801-8. Remove U801
if it is mounted.
- +5V and GND are on J802-1 and J802-5.
Archive containing the hardware related
Xcircuit files.