Nuts and Volts - June 2017

while (1)
{
 // Add your application code
 printf(“Digital Discovery\r\n”);
 __delay_ms(100);
}

The EUSART capture results are displayed by the Discovery and Waveforms in Screenshot 10.

Who Needs a Microcontroller

The Digital Discovery is not just a multi-function monitoring instrument. It can also be “programmed” using JavaScript. This allows the user to generate waveforms and binary sequences that can be used to drive an external device such as a microcontroller.

■ SCREENSHOT 10. Note that the TX and RX Digital Discovery DIO pins are cross-connected with the PIC16F18345’s EUSART pins.

The Discovery’s scripting language also can be used to enable automated data acquisition and analysis.

Let’s keep is simple. Before we run a script, we can check for the presence of a Digital Discovery. Not only can we determine if a Discovery is there, we can request its vitals. This code will return the

if(Device.isConnected())
{
print(Device.SN);
}
else
{
 print(“Digital Discovery Not Found”);
}

We can also use the Discovery’s scripting feature to set up static I/O switches, buttons, and LEDs. This script will force the Discovery’s 24-31 DIO positions to switches.

■ SCREENSHOT 11. The Digital Discovery’s scripting feature is very powerful and provides a means of programmatically controlling the data acquisition and analysis process.

It will also configure its 32-39 DIO positions as buttons:

StaticIO.Channel0.Mode.text = “IOs”;
StaticIO.Channel1.Mode.text = “IOs”;
for(var c = 0; c < 8; c++)
{
StaticIO.Channel0.DIO[c].Mode.text = “Switch”;
StaticIO.Channel1.DIO[c].Mode.text = “Button”;
}

We can eliminate the Z position in our set of switches by executing the following line of script:

StaticIO.Channel0.DIO[0].checked = 1;
 StaticIO.Channel0.DIO[0].Switch.text = “PP”;

The resultant configuration of the Discovery’s I/O pins is shown graphically in Screenshot 11.

PP is short for Push/Pull (1/0). The Z position is included when the switch is in TS (Three-State 1/Z/0) mode.

We are not limited to just configuring the static I/O resources. We can use scripting to manipulate the switches and buttons as well. This line of script will put the least significant switch in a logically zero state:

You Need a Digital Discovery

The Digital Discovery is a very powerful little box.

StaticIO.Channel0.DIO[0].checked = 0;

High speed data acquisition and analysis are only part of the Discovery’s equation. The scripting feature allows you to use it as a stimulus generator for external circuitry.

Conversely, this line of script will force the same switch position to a logical high state: Scripting also enables the automation of some of the Discovery’s core subsystems.