Belleson
commented
1 year ago That's an interesting solution, I like it, thanks for posting! I agree with your comment about how a really nice app is possible with the combination of libraries you mention.
My web socket app does not have a high message rate, just some knobs and buttons on a browser for human interaction. At first I had similar watchdog timer crashes and learned (after days of debug) that doing almost anything in the message handler causes the watchdog to bite.
My solution is maybe not so fast as yours but maybe more flexible. The message handler triggers a timer Ticker (with 1millisec delay) that calls a function and passes a JSON argument. The function asynchronously processes the arg, then calls a client notifier to socket.textAll to update all clients. It requires some care to prevent successive timer calls from short-circuiting previous calls but it's not possible to hang the main loop.
It has not rebooted itself in nearly a year of adding code. Here is a sample message handler, where the incoming message has an action and optional value
Ticker socketActionTicker;
void handleSocketMsg(void *arg, uint8_t *data, size_t len)
{
AwsFrameInfo *info = (AwsFrameInfo *)arg;
if (info->final && info->index == 0 && info->len == len && info->opcode == WS_TEXT)
{
const uint8_t size = JSON_OBJECT_SIZE(8);
StaticJsonDocument<size> json;
DeserializationError err = deserializeJson(json, data);
if (err)
{
#if DEBUG_OUTPUT
Serial.printf("\ndeserializeJson() failed with code %s", err.c_str());
void * dataStr[256];
memset(dataStr, 0, 256);
memcpy(dataStr, data, 255);
Serial.printf("\nSocket message from client:\n%s\n", dataStr);
serializeJsonPretty(json, Serial);
#endif
return;
}
#if DEBUG_OUTPUT
Serial.println("\nSocket message from client:\n");
serializeJsonPretty(json, Serial);
#endif
const char *action = json["action"];
if (strcmp(action, "setInput") == 0)
{
uint_fast8_t newIn = json["value"];
if (newIn != input)
socketActionTicker.once_ms(1, setInput, newIn);
}
else if (strcmp(action, "setPwrDn") == 0)
{
socketActionTicker.once_ms(1, powerDn);
}
else if (strcmp(action, "setPwrUp") == 0)
{
socketActionTicker.once_ms(1, powerUp);
}
else if (strcmp(action, "getInput") == 0)
{
socketActionTicker.once_ms(1, sendInput);
}
else if (strcmp(action, "getPwrState") == 0)
{
uint_fast8_t powerState = digitalRead(POWR); // state is read from hardware
socketActionTicker.once_ms(1, sendPwrSts);
}
}
}
// and a client notification
void notifyClients(JsonDocument& jsonDoc)
{
#if MONITOR_STATUS
Serial.printf("\nENTERING notifyClients(jsonDoc)");
#endif
#if DEBUG_OUTPUT
Serial.printf("\n");
serializeJsonPretty(jsonDoc, Serial);
#endif
char buffer[512];
size_t len = serializeJson(jsonDoc, buffer);
socket.textAll(buffer, len);
}
hoeken
ninja-
I'm writing a server that handles websocket connections using ESPAsyncWebserver and ArduinoJSON. As part of that, I was testing to see how many messages it could handle and I was just generally having things crash a lot. Often, I would get a message like this:
After digging around online, I found this good suggestion on Stackoverflow.
Based on that, I implemented something in my code sort of like below. After that, the crashes are pretty much gone unless I try to push it past 150 messages per second. Its more than happy to chug along at 100 messages per second.
When you do a lot of work in the callback, you run the risk of a watchdog timer reset. If you change the callback to basically just take the message and mark it for processing, then that callback becomes very fast. You then process the message and respond in your main loop which can take as long as you like.
I haven't seen anything in the documentation, so I thought I'd share this with you all as it might save you some headache.
As a side note, running the ESPAsyncWebserver + websockets + ArduinoJSON + serving static html+js+css through SPIFFS is such a killer combo. You can build really nice, responsive websites. I absolutely cannot believe that this thing is running on a little microcontroller. So good. If you want to see how I'm doing it, check out Yarrboard.