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9 years ago.
Checking board type of SX1276
Hello,
I have a pair of 915MHz radios. The Ping-Pong test detects them as SX1276MB1MAS (866MHz) radios even though they are SX1276MB1LAS radios. As a result, bool freq_ok = Radio.CheckRfFrequency(RF_FREQUENCY); of 868000000 passes when it shouldn't for the "L" radio.
The Ping-Pong test works well, despite the radios running at 868MHz. I've turned down the transmit power to 1 and seeing a RSSI of -77dbm and a SNR of 23db. (less than a meter apart), both radios.
...kevin
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1 Answer
9 years ago.
Hi Kevin,
This is weird. The board detection is done through a basic pull-up/down system on the RxTx pin connected to the "A4" platform pin. Can you tell me which platform you are using?
The output power issue is linked to the board selection. Once the correct board is detected, you will have the correct output power (the two boards do not use the same output)
Best Regards,
Gregory
Hi Gregory,
I am using the L152RE. Note that the only issue I saw was the board detection. There is no output power issue. I was just noting that the SX1276 was working properly, even when I deliberately turned the power down to 1 (though I think the code limits the minimum power to 2). Again, no issue with output power.
While poking around in the SX1276Lib, I thought I saw somewhere that there was no code yet developed, that limits frequency selection based on board type. Something that was still left to be done.
...kevin
posted by 09 Apr 2015Hi Kevin,
The board type is detected in the function DetectBoardType() in the file sx1276-hal.cpp. If the correct board is not detected, then there must be an hardware issue linked to the resistor connection (perhaps a wrong value fitted at the factory or a dry joint). The function CheckRfFrequency() was intended to be used to make sure there was no mismatch in the configuration between the 433 MHz and the 868/915 MHz bands but we never implemented it in the end. This function has no influence on the board detection.
Regarding your issue, I can only advise you to check the connection and if the board type is still not detected correctly, then we can organize a board exchange.
Best Regards,
Gregory
posted by 14 Apr 2015
Hi Gregory,
I found one hardware issue using the L152RE. Both LED1 and Arduino D13(SPI SCLK) are the same GPIO pin. You need to remove any occurrence of LED1 when using the SX1276 board because of this issue.
I still haven't found why the wrong board gets detected. I have a 3rd board now on a L152RE that show the wrong board type
posted by Kevin Braun 21 Apr 2015