I have to select a WiFi chip for IoT device that basically has the following features:
- battery powered (non rechargeable)
- acquire sensors using I2C and analog lines every 5 minutes
- connect to an access point and send the data on a TCP socket (HTTP GET)
The battery should last at least for 150,000 connections. I need to roughly estimate the capacity of such a battery...
All the peripherals (sensors, ADC, RF ecc...) are powered ONLY during the acquisition. Hence, during the stand-by, the power consumption is below few tens of uA.
The critical phases are of course connecting to the AP and transmit the data to the server. The devices should first check if the AP is available, otherwise they return to stand-by immediately. And if the AP is available it will be VERY close, so the transmitting power should be kept to the minimum.
Thus I'm looking for a WiFi chip/module which should have this (ideal characteristics):
- wide power supply range: 2.7V - 4.1V
- very fast power up and shutdown
What might change the time required to connect to the AP?
I'm reading through the documentation of ESP-WROOM-02 but I'm wondering if there are more suitable modules for this application.