Conversion between RSSI and LQI in Z-Stack

Z-Stack uses the following formula to convert RSSI and LQI.

LinkQuality = [255* (RSSI-MIN_ED)]/[MAX_ED-MIN_ED]

Therefore with simple algebra

RSSI = MIN_ED+LinkQuality*( MAX_ED-MIN_ED)/255

Default values for MIN_ED and MAX_ED are -87 and 10 respectively.

Then, maybe you can convert RSSI to distance...