Lab 0: Getting Started with the ADALM1000

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Lab 0: Getting Started with the ADALM1000

P116A, Fall 2020

Last updated: 21-SEP-2020

1 The ADALM1000

To adapt to remote learning this quarter, we have reworked our labs around the Analog Devices ADALM1000 module. This is a very versatile module, but its operation can be a bit confusing, particularly since the two software programs we’ll be using use slightly different nomenclature for configuration. The general I/O scheme is shown in Figure 1. There are two functionally identical channels, A and B, each of which is connected to two pins and ground. Each channel can be configured as a voltage source, current source, or left open (referred to as “Off” or “Hi-Z”). By default, the two pins are connected together, and the mod-ule simultaneously measures the voltage and the current. In “Split-I/O” mode, the source pin measures current, while the “In” pin independently measures voltage. Not shown in the picture is an internal 50Ω resistor, which can optionally terminate the input to ground or 2.5V.

In addition to the sources and measurement pins, the module provides ground pins, a 5V pin and a 2.5V pin, which can be used to directly power a prototype breadboard, without the need for any additional power supply.

The goal of this lab will be to get you a bit familiar with the board and the software, as well as to become acquainted with some of the bugs and quirks associated with it.

Figure 1: I/O scheme of the ADALM1000.

2 Prelab Questions

The ADALP2000 kit has mostly 1/8W resistors. What’s the smallest value of resistance that can take the full 5V output of the ADALM1000 without exceeding this power dissipation?

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3 The Alice M1K Software

This quarter’s labs will use the Alice 1.3 Software suite. There are several applications, but we will be using the following:

• The DC Meter Source app: This allows for the configuration of the ADALM1000 source outputs and reading of the inputs.

• The Alice Desktop app: This emulates an oscilloscope.

Detailed instructions for downloading it can be found on the course Canvas page, under “Software”. This page includes known problems and troubleshooting tips. Please read them carefully, install the software on your computer, and verify that it communicates with the ADALM1000 (light turns green).

4 Connecting the ADALM1000 to the breadboard

The accessory kit comes with a number of connecting wires in two lengths and six colors, as well as a “breadboard” for building circuits. The ADALM1000 will be used to power the circuits on the breadboard, as well as to probe the signals on the board.

You’re of course free to connect things any way you want, but Table 1 and Figure 2 show one possible configuration, which provides a unique color for each power level and signal input. The lines in the figure show how the holes in the breadboard are ganged together.

Table 1: Recommended wiring to the ADALM1000 Pin Color Power GND Black 2.5 V Orange 5 V Red Probes CH A Yellow A IN Green CH B Blue B IN White

5 Using the DC-Meter-Source Tool

Start the DC Meter Source tool by clicking the “Alice M1K Meter-Source” icon on Windows or by running the “dc-meter.sh” script on Mac or Unix. You should see a window that looks like Figure 3. The Panels on the left show the voltage and current readout for channels A and B, respectively. There are options for gain and offset corrections, but it’s unlikely you will ever use these. The panels on the right show the output configuration for each channel. When the channel is “Off”, it is not sourcing either current or voltage, and the two radio buttons below are ignored. If the channel is turned “On”, the it will source current or voltage, as determined based on which of the two radio buttons below is selected. The output value will be set by the fields on the bottom.

Finally, if the “Split I/O” radio button is NOT selected, “CH A” is connected “A IN” and “CH B” is connected to “B IN”, while selecting “Split I/O” for a channel disconnects the pair for that channel. In this mode, “CH A” and “CH B” can act as voltage or current sources, while measuring current, and “A IN and “B IN” independently measure voltage. Select “CHA Off”, click “Run” at the upper left, and make the measurements below to fill out Table 2. Assuming you wired things as in Table 1, this will involve

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5V

2.5V

GND

Figure 2: Recommended breadboard connections. Hole connections are indicated by lines. Note the jumper between the two halves of the ground bus.

Figure 3: Source-meter application.

connecting either the yellow or the green lead to the appropriate power bus for each measurement. Click “Stop” when you are done.

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470 Ω

GND

CH A

Figure 4: Connection to 470Ω resistor.

…

Figure 5: Alice Desktop Application, including the Mode and Shape pulldown menus in the Arbitrary Waveform Generator (AWG) window.

Table 2: Please fill out this voltage table. Condition Channel A Reading

Split I/O NOT selected Open

CH A connected to 2.5V bus A IN connected to 5V bus

Split I/O selected Open

CH A connected to 2.5V bus A IN connected to 5V bus

Now disconnect the channel A probes from the board, select “CHA On” and unselect “Split I/O”. Try setting several values for “CA-V” and see if the CA Meter output behaves as expected. NOTE: always click “Stop” before changing the voltage, and then “Run” to measure. Now repeat this with “Split I/O” selected. How did the CA Meter readout change? Why?

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Next, use the breadboard to put a 470Ω resistor (Yellow,Violet,Brown)1, as shown in Figure 4. Set the CA Source panel on the DC-Meter-Source tool to “CH A On”, “CH A V”, and “Split I/O” NOT selected. Try setting the voltage of CA Source voltage from 0 to 5 Volts in one volt increments, and record the voltage and the current measured by CA meter. Remember to click “Stop” before changing the voltage and, and then clicking “Run”.

Now switch the source to current mode by clicking the “CH A I” radio button. Set values from 2 to 10 mA on CA Source and record the voltage and current on CA Meter. Are they what you would expect?

Exit the DC-Meter-Source program by clicking the “X” on the window.

6 Using the Alice Desktop

The Alice Desktop app emulates an oscilloscope Start the program by clicking “Alice M1K Meter-Source” on Windows or running the “alice-desktop.sh” script on Mac or Linux. You should see the windows shown in Figure 5 (the style will be a bit different on a Mac). The main panel emulates an oscilloscope while while the Arbitrary Waveform Generator (AWG) panel controls the outputs of the A and B channels. There are two pulldown menus for each channel. The first is the “Mode” menu”. You can select “Source Voltage Measure Current” (SVMI), “Source Current Measure Voltage” (SIMV), or “Hi-Z”, which correspode to “CHn V”, “CHn I”, and “CHn Off”, respectively, when using the DC-Meter-Source app. As with the DC-Meter-Source tool, you can also select the “Split I/O” option, which will separate the “CHn” and the “n IN” pins.

Finally, Mode includes an option to terminate the channel via 50 Ω to either Ground or 2.5V. This option will normally be left “Open”.

Below, you can select a range and frequency for each channel. In SVMI mode, the range is in volts, while in SIMV mode, it is in milliamps.

Leave the system wired with the 470Ω resistor as in the last section. Set the range of Channel A from 0 to 5V and the frequency to 100. Then set the mode to SVMI and make sure Split I/O is unselected2. Select “Sine” and “Repeat” under the Shape pull down.

On the display panel, use the “Curves” pull down to select CA-V and CA-I. Set the Time scale in the middle upper right to 2 ms/div, the CA V/Div at the bottom left to .5, and the CA mA/Div to 53. Finally, set the “Holdoff” near the upper right to 24. Click “Run”. Does the display make sense? Save the screen shot for your report.

Try at least one one other wave form (triangle, square, etc) and take a screen shot.

7 Lab Report

For your report, answer the questions asked above and include any requested screen shots.

1

On these resistors, yellow is barely visible.

2_{NOTE: an important bug/feature of the system is that any time you change the voltage or the frequency, you need to go}

to the Mode pull down and re-select the mode to get it to take the new value(s).

3_{Always click “Stop” before changing any of the scales. Theres a bug that can cause a runaway otherwise.}

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Appendix: Reading Resistor Color Codes and Measuring Resistance

The ADALP200 accessory box lists all the resistors in the kit, along with their associated color codes, but it’s useful to understand what these mean. The encoding is described in Figure 6. Each resistor has three bands: two digit bands and one multiplier band in powers of 10. There are many mnemonics for remembering the color code, and I’ll leave it to you to google the one you find acceptable. For example, Yellow, Violet, Red would be 47 × 102 = 4.7kΩ. In addition, resistors may have a fourth band indicating the tolerance. In our case, they are all Gold, which means ±5%. If there is no fourth band, the tolerance is ±20%.

Figure 6: The resistor color chart.

Note that these are small resistors and the color codes can be very hard to read. It’s a good idea to double check them with the DVM.