Developers Kit
Preliminary
13
4.3 Pin Descriptions for Connector J1
Special considerations for the hardware interface at connector, J1, are described in this section.
All remaining pin descriptions are standard for serial hardware interfaces.
4.3.1
No Connect
All No Connect pins 2, 4, 6-19, 22, 28-35 and 37 must not be connected to logic high or low
levels, but must be left floating.
4.3.2
Vcc
All Vcc pins 3, 5 and 39 require power of 5Vdc + 5% with ripple of less than 50mv p-p.
4.3.3
Clear To Send (CTS)
Clear To Send (CTS), pin 23, requires a minimum delay of 40
µ
s between (1) and (2) after end of
each data packet.
Figure 1. Timing Note for CTS Pin
4.3.4
Reserved
The reserved pins 24 and 25 are used by AeroComm for internal testing and/or future radio
enhancements. These pins should be treated as No Connect pins and must not be connected to logic high or
low levels, but must be left floating.
4.3.5
Baud Rate Selector (BDSEL)
The Baud Rate Selector (BDSEL), pin 26, provides the user a default method of communicating
with the radio in the event the EEPROM baud rate parameters become corrupted. If pin 26 is logic high
level or not connected, the baud rate will default to the variables specified in EEPROM. If pin 26 is logic
low level, the baud rate will default to 9600 baud.
4.3.6
Forced API Mode 03 (PKTMODE)
Forced API Mode 03 (PKTMODE), pin 27, provides the user a method of programming the radio
from any of the Transparent Serial Interface Modes to the API Serial Interface Mode
. It is required that
CTS
from
Radio
Delay for reply command
*Note:
If level translators are
used the CTS signal will be
inverted coming from the radio.
TXD
MSB First
From Host
Command
Length
Checksum
Data
(1)
(2)
