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Heltec-Aaron-Lee / WiFi_Kit_series

Arduino source codes and toolchain for WiFi_Kit_series made by HelTecAutomation.
GNU Lesser General Public License v2.1
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LoRa Module powering to long #91

Open Maddesh1337 opened 5 years ago

Maddesh1337 commented 5 years ago

Hey guys! Im kind of new to LoRa and microcontrollers, but I am trying to work into a project:

I try to collect Data from a smart meter using an Heltec WiF LoRa 32. To give the node a decent lifetime i wanted to use the deep sleep - but it actually is not working properly if you can believe the very very low powerconsumption in the data sheets.

If I power the ESP32 externally and measure the voltage via an oszilliscope, i get the following voltage (see upoaded picture)

1ohm_1periode

Every 4 secs the ESP32 is waking up due a external wake-up. After this, he reads the serial port, where the data from the smart meter is inserted. After reading the Data he is sending via LoRa and then he should go to sleep.

I hope I could make clear what I am trying to do

Is there someone who can help me figuring out how to fix the deep sleep mode? There are multiple posts, that describing similar problems with the deep sleep, but I havent read a solution for the V1 of the board yet. I am wondering, that the LoRa module is powered so long. I got a transmission time for my data of 17ms, but the module is powering arround 700ms before going off.

Thank you!!

Best regards, Matthias

JBSchueler commented 5 years ago

Depending on the number of preamble bytes, data bytes and which Spreading Factor you are using, the transmission time can vary from 40 to more than 1000 ms.

I am guessing your actual transmission is about 700ms. This means you're ESP32 does go into deep sleep but the SX127x is still transmitting the data. After transmission, depending on the settings, the SX127x goes in idle or receiving mode.