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ifTNT / lora-air-time

A Calculator that calculate the Time on Air (ToA) of LoRa packet. Based on the formula in Semtech's datasheet.
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Lower bandwidth more accurate in SX1262 documentation than SX1276 documentation #1

Open usbpc opened 2 years ago

usbpc commented 2 years ago

For lower bandwidths only one digit after the comma is provided in SX1276 documentation, in the SX1262 documentation an additional digit is provided.

I propose you change the values in the dropdown as follows:

7.8  ->  7.81
10.4 -> 10.42
15.6 -> 15.63
20.8 -> 20.83
31.2 -> 31.25
41.7 -> 41.67

Those values are from Table 6-2 from the SX1262 documentation: https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/2R000000Un7F/yT.fKdAr9ZAo3cJLc4F2cBdUsMftpT2vsOICP7NmvMo

It would be awesome if you could also double check that those values are more accurate like you validated for bandwidth 125 as I don't have the equipment.

I calculated that for a SF12 BW 7.81 255 Byte transmission with 0xFFFF preamble the calculated time would differ by 44.25 seconds.

ifTNT commented 2 years ago

That sounds great! I will try it later. Thanks.

usbpc commented 2 years ago

Another thing that might be intereseing for your calculator, is that the SX1262 has SF5 and SF6 work diffrently to other LoRa ICs. The Exact calculation is in 6.1.4 in the SX1262 documentation. Some more Information on it is in 6.1.1.1.