Hi all,
Over the past few months, we've been grappling with stability issues in RSSI measurements using the nRF52840. Recently, a breakthrough emerged as I began identifying a distinct pattern in the instability, specifically revolving around certain RSSI values.
Through connection of a variable attenuator to the antenna (linked to the nRF52840 receiver), I mapped a range of values exhibiting significant noise. While I'm well aware of the typical values, resolution, and accuracy associated with RSSI in nRF52840, the observed behavior deviates markedly from the expected norm.
To illustrate, let me share RSSI levels across various combinations of output powers and attenuator values. The attached table provides a visual representation, with colors indicating the degree of variance in the RSSI values—red denoting a notable increase in variance.
A conspicuous pattern has emerged, revealing certain values that lack stability across all output powers. Notably, RSSI values such as 49-50 and 59-60 exhibit extreme noise, while the RSSI value of 53 remains consistently flat throughout.
I've thoroughly documented this mapping, and the results are as follows:
As seen above, some levels are stable while other are not.
Have any of you experienced a similar phenomenon in your work? I'm trying to understand if this behavior is widespread or if there's something unique to our setup causing these fluctuations.
Furthermore, if anyone has insights into the potential causes behind this specific behavior, your input would be valuable.
EDIT: **Using SKY66112-11 with nRF52840
thanks!
