Author: Chris Warburton <ChrisWarbo@gmail.com>
Date: Wed Jul 13 09:26:09 PM UTC 2011
Parent: 4c9d4adafd3e0c3ba5e7427a4f7725788c58838a
Log message:
Successfully used to communicate with a C++ program. Ironed out some
kinks in the process, such as initialisation and unneccessarily long
delay() calls.
1: diff --git a/serial_sketch/serial_sketch.pde b/serial_sketch/serial_sketch.pde
2: index 3cb25e9..637b419 100644
3: --- a/serial_sketch/serial_sketch.pde
4: +++ b/serial_sketch/serial_sketch.pde
5: @@ -19,8 +19,8 @@
6: void setup()
7: {
8: delay(1000); // Keep this here so we don't flood the serial line
9: - Serial.println("Starting...");
10: Serial.begin(9600); // Set up Serial library at 9600 bps
11: + Serial.println("{\"status\":\"ready\"}");
12: }
13:
14: void loop()
15: @@ -36,8 +36,8 @@ void loop()
16: else {
17: // Perform whatever actions are defined for this input
18: read_commands(input);
19: + free(input);
20: }
21: - free(input);
22: }
23:
24: char read_char()
25: @@ -47,7 +47,7 @@ char read_char()
26: // forever if you don't send it anything)
27: char data = -1;
28: while ((Serial.available() < 0) || (data < 0)) {
29: - delay(25);
30: + delay(1);
31: data = Serial.read();
32: }
33: return data;
34: @@ -96,15 +96,17 @@ char* read_json()
35: if (read_so_far > pointer_size)
36: {
37: // Try to increase the size of our JSON pointer
38: - // NOTE: We could be more efficient here, eg. doubling the
39: - // pointer size at each realloc, but we favour minimum
40: - // memory usage, so we just bump it up by 1 each time.
41: - char* new_result = (char*) realloc(result, (pointer_size+1));
42: + // NOTE: There are various strategies we could use here
43: + // depending on what we want to conserve. Since we only
44: + // build one JSON string at a time, and free it after
45: + // we're done with it, we don't need to be massively
46: + // conservative in our memory usage
47: + char* new_result = (char*) realloc(result, (pointer_size*2));
48: if (new_result)
49: {
50: // We succeeded in allocating enough memory. Let's use it.
51: result = new_result;
52: - pointer_size++;
53: + pointer_size = pointer_size * 2;
54: }
55: else
56: {
57: @@ -520,6 +522,9 @@ void run_command(char* name, char* value) {
58: if (compare_strings(name,"mode")) {
59: run_mode(value); // Set pin mode
60: }
61: + if (compare_strings(name,"query")) {
62: + run_query(value);
63: + }
64: }
65:
66: void run_read(char* value) {
67: @@ -543,6 +548,7 @@ void run_read(char* value) {
68: if (value[index] == '"') {
69: // We have a string. Let's see if it's what we're after
70: if (compare_strings(value+index, "pin")) {
71: + //Serial.println("Found pin");
72: // This is the number of the pin to read
73: // Find the associated digits
74: index = index + value_length(value+index); // Skip over the name
75: @@ -553,6 +559,7 @@ void run_read(char* value) {
76: index++; // Skip the colon
77: }
78: else {
79: + //Serial.println("...1...");
80: return; // No colon. Abort.
81: }
82: while (value[index] == ' ') {
83: @@ -573,6 +580,7 @@ void run_read(char* value) {
84: continue; // Retest the while condition
85: }
86: if (compare_strings(value+index, "type")) {
87: + //Serial.println("Found type");
88: // This is the type of pin to read.
89: // Find out whether it's analogue or digital.
90: index = index + value_length(value+index);
91: @@ -602,10 +610,9 @@ void run_read(char* value) {
92: }
93: }
94: }
95: - if (pin > 0) {
96: + if (pin >= 0) {
97: // Send our result over USB
98: // {"pinValue":{"type":"digital", "pin":123, "value":123}}
99: - Serial.println();
100: Serial.print("{\"pinValue\":{\"type\":");
101: if (type == 1) {
102: Serial.print("\"digital\"");
103: @@ -861,3 +868,16 @@ void run_mode(char* value) {
104: }
105: }
106: }
107: +
108: +void run_query(char* value) {
109: + // We use "query" as a generic name when all we want
110: + // to send is a value. We simply branch based on the
111: + // contents of value (we'd use a switch, but we would
112: + // have to overload comparison with compare_strings)
113: + if (compare_strings(value, "status")) {
114: + // This is a generic ping request. We just report
115: + // that we're ready so that whatever's on the other
116: + // end knows that it can send commands to us.
117: + Serial.println("{\"status\":\"ready\"}");
118: + }
119: +}