1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
#define RX_ENABLE_PIN 13
#define TX_ENABLE_PIN 12
#define DEBUG_PIN 0
void setup()
{
pinMode(RX_ENABLE_PIN, OUTPUT);
pinMode(TX_ENABLE_PIN, OUTPUT);
pinMode(DEBUG_PIN, OUTPUT);
//always enable RX.
digitalWrite(RX_ENABLE_PIN, LOW);
Serial.begin(38400);
Serial1.begin(38400);
transmit_mode();
}
void loop()
{
for (byte i=32; i<128; i++)
{
digitalWrite(DEBUG_PIN, HIGH);
delay(100);
digitalWrite(DEBUG_PIN, LOW);
Serial.print("OUT: ");
print_byte(i);
rs485_tx(i);
delay(900);
//check for response
while (Serial1.available())
{
byte b = Serial1.read();
Serial.print("IN: ");
print_byte(i);
}
}
}
void print_byte(byte b)
{
Serial.print(b, BYTE);
Serial.print(" / ");
Serial.print(b, DEC);
Serial.print(" / ");
Serial.print(b, HEX);
Serial.print(" / ");
Serial.print(b, BIN);
Serial.println(".");
}
void rs485_tx(byte b)
{
transmit_mode();
Serial1.print(b, BYTE);
int tmp = Serial1.read();
while (tmp != b)
tmp = Serial1.read();
receive_mode();
}
void transmit_mode()
{
digitalWrite(TX_ENABLE_PIN, HIGH); //enable tx
}
void receive_mode()
{
digitalWrite(TX_ENABLE_PIN, LOW); //disable tx
}
|
