SimpleTouchScreenDSO

SimpleTouchScreenDSO

Simple DSO Software for Arduino Uno/MEGA with a Touchscreen Shield.

       

No dedicated hardware, just off the shelf components + c software

Just add:

• A piezo buzzer for audio feedback of touches.
• One capacitator, 2 resistors and a switch to have an AC input.
• few more resistors, capacitors for compensating and a input range select switch for an attenuator.

Features:

• 300 kSamples per second
• Timebase 1-2-5 from 100 microseconds to 500 milliseconds per div (31 pixel)
• Automatic trigger,range and offset value selection
• Single shot mode
• 580 Byte sample buffer
• Min, max, average and peak-to-peak voltage display
• Fast draw mode. Up to 45 screens per second in pixel mode
• Switching between fast pixel and slower line display mode
• All settings can be changed during measurement
• All AVR ADC input channels selectable
• Touch trigger level select
• Touch voltage picker
• 1.1 or 5 Volt reference selectable

Hardware:

• Arduino Uno Rev
• mSD-Shield
• MI0283QT-2 Adapter

Safety circuit range select and AC/DC switch

                ADC INPUT PIN
                      /\
                      |                                   VREF----|R 2.2M|---+---|R 2.2M|---GND
                      |                                                      |
                      |                                                      |
            \   o-----+                                                      o\   o
             \        |                                                        \
    AC/DC     \       =  C 0.1uF                                      AC/DC     \
    Switch     \      |                                               Switch     \
                o-----+                                                           o
                      |                                                           |
                      |                                                           |
                      +---|R 1K  |-----<  INPUT DIRECT >------------o   \         |
                      |                                                  \        |
                      |                                                   \       |
                      +---|R 2.2M|-+---<  INPUT 10 VOLT >------o           \      |
                      +---|R 2.2M|-+                                        \     |
                      +------||----+                    Range select switch  \    |
                      |  app. 80 pF (adjustable trimmer)                      o---+------ A0
                      |                                                           |
  ATTENUATOR          +---|R 3.3M|-+---<  INPUT 20 VOLT >------o                  | Safety circuit
                      +------||----+                              VCC(5V)---|<|---+---|<|---GND
                      |  app. 25 pF
                      |
                      +---|R 4.7M|-|R 4.7M|--+---<  INPUT 50 VOLT >-o
                      |                      |
                      +-----------||---------+
                               app. 10 pF