MODIFICATIONS

The first version of the board was assembled and tested. A few modifications were required for full operation:

• Push to Talk: The 3.3V MKR1000 was unable to drive PTT. An N-channel MOSFET was added
• MKR1000 DAC Driving DRA's MIC IN : requires a 10:1 voltage divider
• DRA AF OUT Driving MKR1000 Analog in: requires 2x amplification. An LM358 Op Amp was added

CURRENT DRAW

• On high-power setting, the DRA draws about 600ma off of the 5V rail

BATTERY MANAGMENT

• Management of the VBATT rail proved to be tricky. The LiPoly rail must not go below about 3.2V. The pack being used has protection, once it kicks in, output goes to 0V