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+## Parts list
+
+The code assumes a Nordic nrf52 system-on-chip and I2C display. 
+It uses Adafruit's Bluetooth LE library, which is a wrapper around Nordic's code, and the U8G2 library for the display. 
+
+Code as provided works with...
+- Adafruit nRF52840 Feather Express https://www.adafruit.com/product/4062
+- Generic 64 x 128 pixel SH1106 OLED display with I2C interface. 
+  - The prototype uses https://www.amazon.com/gp/product/B08V97FYD2. 
+  - The U8G2 library supports a wide range of displays. Using a display with a controller other than the SH1106 involves 
+    - Choosing a different constructor line from the U8G2 examples
+    - Possibly choosing a different value for CONTRAST_DIM
+- An RJ9 cable (landline phone handset cable) to plug into the connector on the bike. 
+- A battery if you want the computer to work without power from the USB connector. Testing is with an Adafruit 4237 https://www.adafruit.com/product/4237. At 350 mAHr, this will power the computer for *about* a week with daily use (testing is incomplete!).
+
+Electrical connections...
+- Bike - RJ9 conductors to 3.3V, ground, GPIO, and analog input - see comments in the code
+- Display - 3.3V, ground, SCD, SCL (standard I2C connection)
+- Battery - with the Adafruit board and battery, plug it in.