A do it your self Arduino Switch Controller for less than $16. Following
is a parts list with prices that include shipping.
Part Price
Arduino Clone $4.45
Relay Module 6.19
RS-232 Module 1.15
DC Regulator 1.53
2A Diode Bridge .25
Hookup Jumpers 2.00
Total $15.57
A breadboard was constructed per the attached schematic and the sketch
(program) was checked out.
The Arduino sketch is as follows:
// Program SC_3 David Nissen 24 Jan 2015
// Switch Control Module to work with Lionel TMCC
int output_pulse = 500; // ms, (500 = .5 sec)
int switch_A = 1; // Switch numbers do not have to be in sequence
int switch_B = 2;
int switch_C = 7;
int switch_D = 8;
int read_delay = 35;
int end_delay = 500;
void setup()
{
Serial.begin(9600);
// ========== Set pins 2-9 to output and set to HIGH (0ff)
int x = 2;
do
{
pinMode(x,OUTPUT);
digitalWrite(x,HIGH);
x++;
} while (x < 10);
// ===========================
}
void loop()
{
int byte_1 = 0;
int byte_2 = 0;
int byte_3 = 0;
int command = 0;
// ========== Loop until byte_1 is FE (254)
do
{
byte_1 = Serial.read();
} while (byte_1 != 254);
// ========== Read byte_2 and byte_3 and form 16 bit command ========
delay(read_delay);
byte_2 = Serial.read();
delay(read_delay);
byte_3 = Serial.read();
command = (byte_2 << 8) + byte_3;
// ========== Switch A straight ==========
if (command == (((switch_A >> 1) + 64) << 8) +((switch_A & 1 ) << 7))
{
digitalWrite(2,LOW);
delay(output_pulse);
digitalWrite(2,HIGH);
}
// ========== Switch A curve ==========
if (command == (((switch_A >> 1) + 64) << 8) +((switch_A & 1 ) << 7) + 31)
{
digitalWrite(3,LOW);
delay(output_pulse);
digitalWrite(3,HIGH);
}
// ========== Switch B straight ==========
if (command == (((switch_B >> 1) + 64) << 8) +((switch_B & 1 ) << 7))
{
digitalWrite(4,LOW);
delay(output_pulse);
digitalWrite(4,HIGH);
}
// ========== Switch B curve ==========
if (command == (((switch_B >> 1) + 64) << 8) +((switch_B & 1 ) << 7) + 31)
{
digitalWrite(5,LOW);
delay(output_pulse);
digitalWrite(5,HIGH);
}
// ========== Switch C straight ==========
if (command == (((switch_C >> 1) + 64) << 8) +((switch_C & 1 ) << 7))
{
digitalWrite(6,LOW);
delay(output_pulse);
digitalWrite(6,HIGH);
}
// ========== Switch C curve ==========
if (command == (((switch_C >> 1) + 64) << 8) +((switch_C & 1 ) << 7) + 31)
{
digitalWrite(7,LOW);
delay(output_pulse);
digitalWrite(7,HIGH);
}
// ========== Switch D straight ==========
if (command == (((switch_D >> 1) + 64) << 8) +((switch_D & 1 ) << 7))
{
digitalWrite(8,LOW);
delay(output_pulse);
digitalWrite(8,HIGH);
}
// ========== Switch D curve ==========
if (command == (((switch_D >> 1) + 64) << 8) +((switch_D & 1 ) << 7) + 31)
{
digitalWrite(9,LOW);
delay(output_pulse);
digitalWrite(9,HIGH);
}
// ========= Clear serial buffer
for (int z = 0; z < 256; z++)
{
Serial.read();
}
// =============================
delay(end_delay);
}
If you use the Arduino clone a Special USB driver is required in order
to download the sketch from you PC.
The RS-232 Rx line must be disconnected in order for the sketch to be
downloaded.
Future projects using this breadboard include an Accessory Controller.
Only a new sketch would be required.
The Tx line from the Arduino to the RS-232 module is not required for
the Switch Controller but was included for future projects that will
send commands out to the base. One possible project could receive a
command from the handheld and then output a command to the base such
as ASC 50 to send a series of whistle commands to a train.
The cable from the project to the base has 3 wires also to make it
bidirectional. Since it is symetrical it doesn't matter which end goes
to the base and which end goes to the project.
