Schematics sx1276 module or rfm95 module

End Devices (Nodes) Hardware
1

Hi all,
I have been looking for the schematics of these modules:

  1. https://es.aliexpress.com/item/32984655636.html?storeId=4781036&spm=a219c.search0104.3.2.5572538blqY0lG&ws_ab_test=searchweb0_0%2Csearchweb201602_4_10065_10068_10547_319_317_10548_10696_10084_453_10083_454_10618_10307_10820_10821_10301_10303_537_536_10059_10884_10887_321_322_10103%2Csearchweb201603_53%2CppcSwitch_0&algo_expid=e1baca92-e584-4686-b521-3fa9dddac482-0&algo_pvid=e1baca92-e584-4686-b521-3fa9dddac482

  2. https://es.aliexpress.com/item/32811523237.html?storeId=1795152&spm=a219c.search0104.3.2.54526a4c9HevEX&ws_ab_test=searchweb0_0%2Csearchweb201602_4_10065_10068_10547_319_317_10548_10696_10084_453_10083_454_10618_10307_10820_10821_10301_10303_537_536_10059_10884_10887_321_322_10103%2Csearchweb201603_53%2CppcSwitch_0&algo_expid=79facfca-f5c0-4e09-8463-8eb8755c0a5a-0&algo_pvid=79facfca-f5c0-4e09-8463-8eb8755c0a5a

and I can not find them. Does anyone have them?

2
3

Thank you, but that document I have already seen, is the same as the schematics of the board SX1276MB1MAS:
https://www.digikey.es/product-detail/es/semtech-corporation/SX1276MB1MAS/SX1276MB1MAS-ND/5015648

I need those schematics specifically because when I use the SX1276MB1MAS board the project works fine (with STM32L476RG-NUCLEO board and Lora-net libraries), but when I use the other modules it does not work because the levels of RSSI and SNR are very low.

4

Who knows who the first one, it looks like a copy of an RFM95, but not an RFM95, so who knows if it works. If the ‘supplier’ cannot give you the information on this module that you require, consider sticking to the well known modules.

The second one is clearly labeled as RFM95 and data on that is easy to find via a Google search.

Whats the application, the circuit diagrams are not needed to use the devices ?

5

I doubt very much the schematics will help you, most all LoRa modules (from reputable suppliers) work the same and have near identical performance.

‘Very low’ RSSI and SNR are normally indicative of a problem elsewhere, damadged modules or very poor antennas.

6

The first is the same chip as that of the SX1276MB1MAS board.
The second one is an RFM95 from HopeRF and I can not find schematic in Google.
The libraries that I use are: https://github.com/Lora-net/LoRaMac-node
For example, the library manage the pin RXTX/RFMOD (PIN 20) that in SX1276MB1MAS board can access but in others modules cant access and it manages by the own module. I need the schematics for this.

With SX1276MB1MAS the RSSI and SNR are good in 2 meters (-23dBm and 8 dB, respectively) and it send data over long distances
but with the others modules in 2 meters are poor (-101dBm and -10dB, respectively) and when I leave the room (5 meters) TTN dont receive data.

Obviously, I always use the same program

7

There may well be some boards, such as the SX1276MB1MAS that require you to implement your own RX\TX switching.

But this is not the case for the RFM95 module you linked to, RX\TX switching is automatic, you dont need the module schematic to understand how to use the device properly, the libraries do it all for you.

1 Like