K8LG PIC KISS TNC
VERSION 1.2
G. M Palmer, K8LG
NOVEMBER 2004 UPDATE
Figure 1: K8LG PIC KISS TNC Version 1.2
OPERATION
This
TNC operates as any TNC in KISS mode.
Set the jumpers for desired operation: JU1 for high (shorted) or low (open)
level transmit audio, JU2 for software CD (open) or hardware CD (shorted), JU3
for normal operation (open), and JU4 for the serial port speed matching the
computer/host software. It is
recommended that JU2 be left open for software CD.
Connect
the radio cable to J3 (5 pin DIN connector); the computer serial port cable to
J2 (DB-9 connector); and the power cable (9 to 15V) to J1. On power up the firmware will flash the LEDs
three times and set parameters: TX Delay = 500 ms, Slot Time = 100 ms, Persistence
value = 63, TX Tail Time = 20 ms, and Half Duplex as default values. These parameters will be updated by the
host. The transmit
audio level should be adjusted (calibrate function) so the transmitter has 3
KHz deviation.
The
host software must be set to operate in KISS mode with this TNC. There is no need to send a KISS mode setup
but if it is sent it will be ignored.
CALIBRATION FUNCTIONS
The
calibration function will allow the TNC to be keyed and either a MARK or SPACE
tone be sent. To enter calibration mode
place a jumper block on JU4 and apply power.
Using a terminal program (Hyperterm, TELIX, etc.) you will receive a
prompt asking for an input of K, M, S, or E.
These commands are for:
K Key the transmitter (toggle transmit).
M Set the MODEM tone to MARK
S Set the MODEM tone to SPACE
E Exit calibrate mode.
The transmit audio level is adjusted with R4 (10K pot.) located near the DIN
connector. Jumper JU1 is used to select transmit audio range. With JU1 shorted the audio level will
be in high range (up to about 1.5V RMS) and with the jumper off the audio level
will be in low range (up to about 180 mV RMS).
The Twist or difference between MARK and SPACE transmitted audio
levels may be measured by going between MARK and SPACE tones and observing the
transmitter deviation.
The
K8LG PIC KISS TNC has a TNC-2 type watch-dog timer to limit the transmitter
key-up time in the event of a software failure. The watch-dog timer may be
checked by using the K calibrate function to key the
transmitter and watching how long the red PTT led remains on. The time-out value is set by the RC time
constant of C21 and R18 and may be changed by changing either component.
Remove
the short on JU3 when the calibration is complete.
JUMPER
SETTINGS FOR K8LG PIC KISS TNC Ver. 1.2
JU1: This jumper sets the transmit audio level range.
JU1
ON High range
JU1 OFF Low range
JU2: This jumper sets the Carrier Detect (CD) mode.
JU2 ON Use the MX-614 hardware CD line. This
requires squelched audio.
JU2 OFF Use software Data Carrier Detect (DCD) allowing open squelch
operation.
JU3: This jumper selects TNC mode:
JU3 ON
Calibrate mode. This allows the setting transmit audio level
for proper
deviations.
JU3 OFF Normal mode, TNC operates as KISS TNC.
JU4: This jumper is used to select the TNC to computer serial
speed. Speed shown set to 19200 baud in
photo.
JU4-3 JU4-2 JU4-1 Terminal
speed
ON ON
ON 1200 BAUD
ON ON OFF 2400 BAUD
ON OFF OFF 4800 BAUD
OFF OFF ON 4800 BAUD
OFF ON ON 9600 BAUD
OFF ON OFF
19200 BAUD
OFF OFF ON 38400 BAUD
OFF OFF OFF 38400 BAUD
JU5: Not used in this version.
LED FUNCTION
D4 Yellow LED ------ DCD active when receiving valid AX.25 frame.
D3 Green LED ------ Active
when transmitting an AX.25 frame from host to TNC.
D2 Red LED --------- On when
PTT line is active.
D5 Red LED --------- Power on indicator, on all times.
D6 Green LED ------ Not currently used.
On power-up the firmware will flash the LEDs D4, D3, D4, and D6 in sequence. This is an indication the firmware is operating correctly and the TNC has initialized.
CONNECTOR PIN-OUTS FOR K8LG
PIC TNC
J1: POWER CONNECTOR. 2.1mm male connector.
Center pin --- Positive
Sleeve
-------- Negative
Current requirement: 10
to 25 mA with reverse polarity protection.
J2: SERIAL PORT CONNECTOR. Female DB-9 RS-232 connector.
1 No connection
2 Transmit data (From the host)
3 Receive data (To the host)
4 No connection
5 Signal ground
6 No connection
7 Request To
Send (RTS) (From the host)
8 Clear To
Send (CTS) (To the host)
9 No connection
At this time RTS and CTS signals are not used. These may be used in future software
versions. Early versions had a male DB-9
connector at J2.
J3: RADIO CONNECTOR. 5 pin female DIN connector in TAPR pin-out
format.
1 Transmit audio. (To radio Mic. or audio input.)
2 Signal ground
3 Push to talk (PTT). (Transmitter keying line.)
4 Receive audio. (From radio to TNC.)
5 No connection.
PARTS LIST
C1-C6
-------------------------------------------------------------------- 1.0 uf /
25V
C7, C8, C12,
C14-C18, C20 ------------------------------------------ 0.1 uf / 50V
C9, C19,
C21------------------------------------------------------------ 22 uf / 25V
C10, C11
---------------------------------------------------------------- 22 pf / 50V 5%
D1
------------------------------------------------------------------------ 1N4001
D2 D6
------------------------------------------------------------------ LED
D7
------------------------------------------------------------------------ 1N914
J
-------------------------------------------------------------------------- Zero
Ohm jumpers (21 total)
J1
------------------------------------------------------------------------- 2.1mm
power connector
J2
------------------------------------------------------------------------- DB-9
female connector
J3
------------------------------------------------------------------------- 5 pin
female DIN connector
JU1
----------------------------------------------------------------------- 2 pin
header (TX audio select)
JU2
----------------------------------------------------------------------- 2 pin
header (CD select)
JU3
----------------------------------------------------------------------- 2 pin
header (Operate/Calibrate)
JU4
----------------------------------------------------------------------- 6 pin
header (Serial speed select)
JU5
----------------------------------------------------------------------- 2 pin
header (Unused)
OSC ----------------------------------------------------------------------
19.6608 MHz crystal osc.
Q1
------------------------------------------------------------------------ 2N7000
(PTT keying)
R1, R2, R5
-------------------------------------------------------------- 100K 0.25W
R3 ------------------------------------------------------------------------
51K 0.25W
R4
------------------------------------------------------------------------ 10K
Pot.
R6, R12
R15, R17, R19 -------------------------------------------- 10K 0.25W
R7 R11----------------------------------------------------------------
1.2K 0.25W
R18
---------------------------------------------------------------------- 1.5M
0.25W
U1
----------------------------------------------------------------------- 7805
(5V pos. regulator)
U2
----------------------------------------------------------------------- MAX232
U3
----------------------------------------------------------------------- MX-614
(MODEM)
U4
----------------------------------------------------------------------- 74HC14N
U5
-----------------------------------------------------------------------
PIC16F874-20I/P
U6
----------------------------------------------------------------------- MCP130
(RESET)
U7, U8
------------------------------------------------------------------ 74HC574N
U9
-----------------------------------------------------------------------
62256ALP-10 (32KB memory)
X1
-----------------------------------------------------------------------
3.579545 MHz crystal
Socket
------------------------------------------------------------------ 40 pin for
U5
Socket
------------------------------------------------------------------ 28 pin for
U9
Hardware
-------------------------------------------------------------- 1
BILL
OF MATERIALS
-------------------------------------------------------------------------------
D:\kiss\Kiss_tnc_F.bom Bill of Materials
-------------------------------------------------------------------------------
Item
Count Label-Value Pattern Designation(s)
1
1 RS-232 DB9/F J2
2
6 Jumper AXIAL0.5 J,J,J,J,J,J
3
8 Jumper AXIAL0.3 J,J,J,J,J,J,J,J
4
7 10K AXIAL0.3 R6,R12,R13,R14,R15,R17,R19
5
1 2.1mm Power RAD0.3 J1
6
2 Jumper AXIAL0.8 J,J
7
6 0.1uf RAD0.1 C7,C14,C15,C16,C17,C20
8
1 1.5 Meg AXIAL0.3 R18
9
2 1.0uf RAD0.1 C1,C2
10
1 1N914 AXIAL0.3 D7
11
1 MCP130 TO-5 U6
12
2 1.2K AXIAL0.3 R10,R11
13
1 LED-5 RAD0.1 D6
14
3 0.1uf RAD0.2 C8,C12,C18
15
1 LED-3 RAD0.1 D4
16
1 LED-2 RAD0.1 D3
17
1 LED-1 RAD0.1 D2
18
1 2N7000 TO-5 Q1
19
3 100K AXIAL0.3 R1,R2,R5
20
1 3.5728MHz XTAL1 X1
21
1 JU1 RAD0.1 JU1
22
1 10K POT VR4 R4
23
1 51K AXIAL0.3 R3
24
1 RADIO DINC/STDT/5 J3
25
4 1.0uf RAD0.2 C3,C4,C5,C6
26
1 MAX-232 DIP16 U2
27
1 PIC16F877 DIP40 U5
28
1 62256 DIP28 U9
29
2 74HC574 DIP20 U7,U8
30
1 MX-614 DIP16 U3
31
1 XTAL OSC DIP14 OSC
32
1 LED-4 RAD0.1 D5
33
2 22pf RAD0.1 C10,C11
34
3 22uf RAD0.1 C9,C19,C21
35
1 JU3 RAD0.1 JU3
36
1 JU2 RAD0.1 JU2
37
1 JU4 IDC10 JU4
38
1 JU5 RAD0.1 JU5
39
1 74HC14 DIP14 U4
40
3 1.2K AXIAL0.4 R7,R8,R9
41
5 Jumper AXIAL0.4 J,J,J,J,J
42
1 1N4002 AXIAL0.4 D1
43
1 7805 TO-220 U1
Total number of components
: 86