Update README.md

README.md

@@ -9,6 +9,9 @@ audio input and output circuitry, PTT signalling circuitry and EEPROM for
 storing configuration that is nearly identical to the TNC3.  It only lacks the
 Bluetooth adapter and battery charging circuitry.
 
+The Breadboard TNC3 connects to a computer (or Android device with a USB-OTG
+adapter) via a USB cable.
+
 ## Bill of Materials
 
 The Breadboard TNC3 is designed around the STMicroelectronics Nucleo32 board
@@ -16,3 +19,27 @@ with the STM32L432KC chip.  The total bill of materials (BOM) cost is about
 $25 (USD).
 
 You will need:
+
+ - 830-point breadboard (standard single row) or larger.
+ - STM Nucleo32-L432KC dev board
+ - 2 2N7009 N-channel MOSFETs (TO-92)
+ - 2 Schottky diodes
+ - 1 MCP6004 4-channel op amp (14-PDIP)
+ - 1 AT24C32E-PUM 32kb I2C EEPROM (8-PDIP)
+ - 1 Red LED
+ - 1 Green LED
+ - 1 TRRS 3.5mm 4-pole jack
+ - various resistors and capacitors
+ - Hookup wire
+ 
+## Schematic Diagram
+
+## Theory of Operation
+
+## Build Instructions
+
+## Progarmming the Breadboard TNC3
+
+## Running the Test Program
+
+