Graph your WiFi signal strength RSSI (dBm) on a Nokia 5110 PCD8544 LCD module.
Signal strength (RSSI) is the usable strength of the radio waves, expressed in decibels (db) between 0db (strongest) and -120db (weakest). The closer it is to zero, the stronger/cleaner the signal is. For WiFi, the normal range is -45db to -87db. Anything below -85db is generally unusable, and over -50db can be considered perfect.
| RSSI | Quality |
|---|---|
| > -50db | Fantastic |
| ~= -50db | Great |
| ~= -75db | Average |
| ~= -85db | Poor |
| ~= -95db | Unusable |
- WeMos D1 Mini (ESP8266)
- Nokia 5110 PCD8544 84x48 monochrome LCD
- 8 jumper wires
- Breadboard
- 5V power source (USB 4xAA battery pack)
Add these to your Arduino IDE using Manage Libraries.
- Adafruit GFX Library
- Adafruit PCD8544 Nokia 5110 LCD library
- There is a pull request that adds ESP8266 support:
- adafruit/Adafruit-PCD8544-Nokia-5110-LCD-library#27
- If this has not been merged yet, you will need to manually copy the changes across
| WeMos D1 Mini | Nokia 5110 PCD8544 LCD | Description |
|---|---|---|
| D2 (GPIO4) | 0 RST | Output from ESP to reset display |
| D1 (GPIO5) | 1 CE | Output from ESP to chip select/enable display |
| D6 (GPIO12) | 2 DC | Output from display data/command to ESP |
| D7 (GPIO13) | 3 Din | Output from ESP SPI MOSI to display data input |
| D5 (GPIO14) | 4 Clk | Output from ESP SPI clock |
| 3V3 | 5 Vcc | 3.3V from ESP to display |
| D0 (GPIO16) | 6 BL | 3.3V to turn backlight on, or PWM |
| G (GND) | 7 Gnd | Ground |
