Software & Electronics Design

Frequently Asked Questions

Changing the measurement range

The input range of the USB scope can be changed by adding two resistors to the input line of the scope. Schematic below shows the electrical diagram of the input circuit. Adding a resistor with a value of 10 kOhm and a resitor with value "R_in" will change the full scale of the scope. Check the table below to find the value for "R_in" that creates the measurement range you need. Input resistance

Table below shows the values to be used for "R_input" to extend the measurement range.

R_in value Measurement range
no resistor 0 V to +5V
10 kOhm 0 V to +10 V
20 kOhm 0 V to +15 V

Be carefull when using above resistors to increase the input range and do NOT connect any voltage higher than +5V directly to the scope. This might damage the scope and the USB port.

Error: "No USB scope found. Check your hardware"

This message occurs if the scope hardware is not conneced before the program is started. Also this message can happen if the USB driver is not installed correctly. If you open your "device" manager in Windows, you should see a serial device as shown below. windows device manager

(number of the COM port may be different on your computer).