Adafruit IO data rate limit

Question

I'm trying to send data from multiple ESP-8266 to feeds on my Adafruit IO account. The problem is that when I try to send new values, I'm faced with a ban from publishing because the 2 seconds time limit is violated when two or more of my MCUs happen to send data at the same time (I can't synchronize them to avoid this). is there any possible solution to this problem?

Answer 1

I suggest to consider those three options:
A sending token which is send from one ESp to the next. So basically all ESPs are mot allowed to send. If the token is received its allowed to send - waits the appropriate time limit hands the token to the next ESP. This solution has all Arduinos connected via an AP/router and would use client to client communication.
It can be setup fail safe, so if the next ESP is not available (reset/out of battery etc) you take the next on the list and issue an additional warning to the server
The second solution could be (more flexible and dynamic BUT SPO - single point of failure) to set up one ESP as data collector to do the sending.
If the ESps are in different locations you have to set them up that they meet the following requirement:

If you have a free Adafruit IO Account, the rate limit is 30 data points per minute. If you exceed this limit, a notice will be sent to the {username}/throttle MQTT topic. You can subscribe to the topic if you wish to know when the Adafruit IO rate limit has been exceeded for your user account. This limit applies to all Data record modification actions over the HTTP and MQTT APIs, so if you have multiple devices or clients publishing data, be sure to delay their updates enough that the total rate is below your account limit.

so its not 2 sec limit but 30/min (60/min if pro) so you limit sending each ESP to the formula:

30 / Number of ESPs sending to I/O -> 30 / 5 = 6 ==> 5 incl. saftey margin

means each ESP is within a minute only allowed to send 5 times. Important if the 5 times send limit is up it HAS to wait a minute before the next send.

Answer 2

The answer is simple, just don't send that frequent.

In the IoT world

• If data need frequent update (such as motor/servo, accelerometer, etc.), it is often that you'd want to keep it local and won't want/need to send it to the cloud.
• If the data need to be in the cloud, it is often not necessary need to be updated so frequently (such as temperature/humidity).

Alternatively, if you still think that your data is so critical that need to be updated so frequently, dedicate one ESP as your Edge Gateway to collect the data from sensor nodes, and send it to the cloud at once, that actually the proper way of an IoT network design with multiple sensor nodes.

If that still doesn't work for you, you still have the choice of pay for the premium service to raise the rate limit, or build your own cloud service and integrate it with your Edge Gateway.