Pololu USB AVR - Manual (Page 32)

Pololu USB AVR programmer configuration utility for Windows.
Target VDD Monitor
The USB AVR programmer monitors the voltage of the target AVR while it is being programmed to ensure that ISP
commands are only sent when the AVR’s VDD is at a safe level, since attempting to program an underpowered AVR
can permanently disable it. There are two parameters that control this feature:
• Minimum Allowed: This parameter determines the lowest level (in millivolts) that the target AVR’s VDD
is allowed to go. If the target AVR’s VDD drops below this level, the programmer immediately aborts
programming and turns on the red programming LED. Lowering this value will allow programming of AVRs at
lower voltages, but will make it more likely that the programmer will send ISP commands to the AVR while the
AVR is running at an unsafe voltage. The default value is 4384 mV.
• Maximum Range Allowed: This parameter determines how much the target AVR’s VDD measurements are
allowed to vary (in millivolts). When the programmer recieves an ISP programming request, it starts keeping
track of the maximum and minimum measurements of the AVR’s VDD. If the difference between the maximum
and minimum exceeds the allowed maximum range, the programmer immediately aborts programming and turns
on the red programming LED. Increasing this value will allow programming of AVRs under less stable power
conditions, but will make it more likely that the programmer will send ISP commands to the AVR while the AVR
is running at an unsafe voltage. The default value is 512 mV.
Measurements From Last Programming
This section displays the minimum and range of the target VDD measurements from the last time the programmer was
in programming mode or tried to enter programming mode. This can help determine whether programming problems
are due to the target’s power supply.
Pololu USB AVR Programmer User's Guide © 2001–2014 Pololu Corporation
3. Getting Started in Windows Page 32 of 54