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Getting Started with the Micromite Want to learn how to program a microcontroller? There’s no easier way to start than with this guide to using the Micromite. With this easy-tofollow article, all you need is a Micromite chip and a couple of hours and you can become an embedded programmer. Part 1 – by Geoff Graham T he Micromite, in its various configurations, has become a big hit with thousands built. Readers have used it for jobs ranging from controlling a heating element through to the brains behind an intelligent amplifier/tuner. But there are still many people who would love to “get into it” but don’t know how to program in BASIC (or any other computer language). Is this you? This tutorial will guide you through the basics of using the Micromite, programming in the BASIC language and show you how to get the Micromite doing something useful almost straight away. We’ll start with some small, easy programs and progress to learning a few of the more advanced features which make the Micromite so versatile. Silicon Chip readers should be familiar with the Micromite by now. Essentially, it is a super-fast 32-bit microcontroller programmed with an advanced BASIC interpreter called MMBasic. You use MMBasic to write your programs and because it is designed to be easy to use, you can get your project running in far less time than if you were writing in a complex language like C or assembly. To run the examples below, you can use a bare Micromite chip with just one capacitor, one resistor and a 3.3V power supply, as shown in Fig.1. However, we strongly suggest that you put together the Micromite LCD BackPack, as described in the February 20  Silicon Chip 2016 issue as this will be required for some of the examples in subsequent articles in this series. The BackPack can do much more than a bare Micromite, thanks to its 2.8-inch LCD touchscreen and it has been extremely popular, with around 1000 built! So if you don’t already have an LCD BackPack, we suggest you put one together. Regardless, once you have your Micromite up and running, you will need to connect it to your computer using a USB/serial adaptor and terminal emulator, as described in the February 2016 construction article and also in the side-panel later in this article. Once you’ve done that, you can try out all the example code in this article. When you have it set up and working, wire up a LED to the BackPack’s pin 14 (as shown in Fig.2) and load 2 x AA OR 3.3V DC SUPPLY +2.3V to +3.6V <at> 26mA 1 28 27 8 28-PIN MICROMITE the following program using MMEdit: SETPIN 14, DOUT DO PIN(14) = 1 PAUSE 200 PIN(14) = 0 PAUSE 300 LOOP Run it (by clicking the icon of the running man in the toolbar) and you should see the LED flashing twice per second (ie, 2Hz). In microcontroller circles, flashing a LED is pretty much the most basic test program you can write, a sort of “hello world” program. It demonstrates that your chip is running correctly and you are able to program it and control its I/O pins properly. This is the hardest part; from now on you can simply build a program pieceby-piece on this foundation, until you have it doing what you want. Fig.1: the best option for experimenting with the examples in this tutorial is the Micromite LCD BackPack but if you wish to just use the 28-pin Micromite on a breadboard, this is the basic circuit necessary to get it going. Note that the capacitor must be tantalum or ceramic type. 20 10µF 6V Console TX Console RX CERAMIC OR 11 12 13 47µF 6V 19 TANTALUM siliconchip.com.au This short program works by first configuring the pin connected to the LED as a digital output (“DOUT”). It then enters an endless loop (DO … LOOP) where it turns the LED on and off with pauses in between. The full syntax of the initial SETPIN command is: SETPIN nn, mode Where “nn” is the pin number on the Micromite to configure and “mode” is how you would like the pin to be configured. The mode can be: AIN – analog input (ie, measure a voltage between 0V and 3.3V) DIN – Digital input (ie, sense low [~0V] or high [~3.3V]) FIN – Measure the frequency of the signal on pin PIN – Measure the period (ie, the time between positive going edges) of the signal on the pin CIN – Count the number of pulses on the pin DOUT – Digital output (either held low [~0V] or high [~3.3V]) Note that the pin number “nn” refers to the physical pin number of the chip as shown in the data sheet. This makes it easy for you to cross-reference a component connected to the chip with the programming commands that will manipulate it. We will go through the other modes later but all you need to know for now is that the first line of the program sets pin 14 to be a digital output. To make that pin go high, you assign a non-zero number to it, as in “PIN(14) = 1”. To make it go low, you assign the value of zero to it, as in “PIN(14) = 0”. The I/O pins on the Micromite can supply a reasonable amount of current for driving external components (about 10mA each) and as the LED will only draw about 4mA, due to its series current-limiting resistor, that Fig.2: if you are using the Micromite LCD BackPack, this is how you should connect the LED to try out some of the examples. You can plug the BackPack into a solderless breadboard or you can directly connect to the BackPack I/O pins as shown here. Note CTRL-C can get you out of all sorts of difficult situations so remember it because you will find useful at some time in the future. is well within the chip’s capability. PAUSE command The PAUSE command in our example program does exactly what its name suggests, ie, causes the program to pause or wait for a certain amount of time. This time is expressed in milliseconds, so PAUSE 200 will suspend the running of the program for 200ms or one fifth of a second. You need this delay because the BASIC program runs quite fast and without the PAUSE commands, the LED would flash at such a rate that you would only see a dim light. You can verify this by entering the program without the PAUSE commands: SETPIN 14, DOUT DO PIN(14) = 1 PIN(14) = 0 LOOP If you attach an oscilloscope to pin 14, you will see that your BASIC program is toggling the output at about 9kHz. There are four commands being executed in this loop, suggesting that each command requires an average of 28µs to execute. Note though that if you run this same program on the Micromite Plus (eg, the Explore 64, Explore 100 or Micromite Plus LCD BackPack), it will run faster, which is a good demonstration of why it’s a bad idea to rely on execution speed for program timing. Another part of this program that needs explanation is the DO … LOOP construct. This forms an “endless loop” which causes the contained commands to be repeated over and over forever! When MMBasic reaches a LOOP command, it searches backwards for a matching DO command and then jumps back to there and executes the following commands again. Fig.3: pin connections for the microUSB-to-serial converter. Note that the RX pin from the converter goes to the TX pin on the board, and vice-versa. siliconchip.com.au February 2017  21 Setting up the Micromite As mentioned at the start of the article, the best set-up to play with the examples in this series of articles is the Micromite LCD BackPack, which was featured in the February 2016 issue of Silicon Chip. This simple project uses fewer than ten components and can be built in half an hour. It includes a 3.3V power supply, 28pin Micromite and LCD touchscreen. In future tutorials, we will cover drawing graphics on the display and using the touch interface, so the Micromite LCD BackPack will enable you to follow the examples and experiment for yourself. A complete kit is available from the Silicon Chip Online Shop, which includes all the parts you need to build the BackPack, here: www. siliconchip.com.au/Shop/20/3321 The February 2016 issue which describes the Micromite LCD BackPack can also be purchased from: • w w w. s i l i c o n c h i p . c o m . a u / Shop/2/3317 (printed copy) • w w w. s i l i c o n c h i p . c o m . a u / Shop/12/3330 (online version) • We can also supply a USB/serial interface module to connect it to your computer at the same time: • w w w. s i l i c o n c h i p . c o m . a u / Shop/7/3437 (with USB TypeA plug, no cable required) • w w w. s i l i c o n c h i p . c o m . a u / Shop/7/3543 (with microUSB Type-B socket, cable required) However, you do have the option of simply plugging a 28-pin Micromite into a solderless breadboard and use jumper leads to connect up the LCD display whenever you needed to. Either choice is viable so it is up to you. If you would like to follow this route, you can purchase just the 28-pin Micromite from the Silicon Chip Online Shop at: www. siliconchip.com.au/Shop/9/2908 Connecting to a computer To program the Micromite using MMBasic, you can enter commands and programs via the console. The console is a serial interface over which you can issue commands to configure the chip and edit/run programs. MMBasic also uses the console to display error messages; your own programs can also display messages on the console, and receive user input from it. A serial interface consists of two signals. One, referred to as TX or TXD (for transmit [data]) carries coded signal data from the device while the other, called RX or RXD, receives similarly coded signals. ASCII encoding is used for each character sent or received. The speed of transmission is referred to as a baud rate which is another way of saying bits per second. The Micromite starts up with its console serial port set to a baud rate of 38400. The serial port uses TTL signalling which means that the signal swings between zero and 3.3 volts. To use the serial console, you need a USB-to-serial converter which plugs into a USB port on your PC and on the other end, connects to the Micromite’s serial console. This provides a virtual COM port on which your PC can send and receive data from the Micromite. Two suitable devices, both using the CP2102 chip and available from the Silicon Chip Online Shop, are mentioned above. The CP2102 and how it works is described in greater detail in the January 2017 issue. The picture opposite shows how such a converter is connected to the 28-pin Micromite on a solderless breadboard. Note that this photo shows the Micromite with an independent 3.3V power supply but the 3.3V output on the converter can be used to power the Micromite. When the converter is plugged into your computer and the correct driver is installed, it will appear as a serial port (eg, COM29 in Windows). You then need to start a terminal emulator on your computer to open the port. For Windows, we recommend Tera Term version 4.88 which is a free download from http://tera-term. en.lo4d.com Set the interface speed to 38400 baud as shown in Fig.4 and connect to the serial port created by the USB to serial converter. With this done, apply power to the Micromite and in the terminal emulator’s window, you should see the Micromite’s startup banner as shown in Fig.5. At this point, you can enter, edit and run programs from the command prompt using nothing more than the terminal emulator and a USB cable. When your program is running successfully on the Micromite, you do not necessarily need the console, so you can set the Micromite to automatically run its program on startup (OPTION AUTORUN ON). However, unless you managed to get the program perfectly correct the first time (unlikely), you will find yourself repeatedly reconnecting to make one tweak or another, so many people leave the USB-to-serial converter permanently connected (they do not cost much). Troubleshooting What if it does not work the first time? Fig.4 (left): startup screen for Tera Term, where the baud rate and other values can be set on launch. Fig.5 (right): startup banner for the Micromite running in the Tera Term console. 22  Silicon Chip siliconchip.com.au 1) Check your power supply. Is it 3.3V and is it stable and free from electrical noise? If you have doubts, you can use two fresh AA batteries in series as a power source for testing. Then check that 3.3V is on each pin shown in Fig.1 and that each ground pin is correctly connected to 0V. 2) Check the 10µF or 47µF capacitor connected to pin 20 on the 28-pin chip or pin 7 on the 44pin chip. As mentioned earlier, this capacitor must be a ceramic or tantalum type; an electrolytic capacitor will not work. 3) Has the chip been properly programmed? If you programmed it yourself, check that the programmer did report that the programming operation was successful. A current draw of about 26mA means that the chip is working correctly and running the BASIC interpreter. Less than 10mA indicates that MMBasic is not running and: • a power or ground connection is faulty; • the 10/47µF capacitor is faulty or not connected or; • the chip was not programmed correctly. If you have a current draw of about 26mA, the fault is most likely with the USB-to-serial converter or your terminal emulator. To check these two elements, disconnect the serial connections from the Micromite and short the TX and RX pins of the converter together. When you type something on the keyboard into the terminal emulator, you should see the same characters echoed on the screen. If not, diagnose and correct the error in your USB-to-serial converter and terminal emulator before proceeding. If the above test is OK (ie, keystrokes echo on the screen), the only possible remaining fault is in your connection of the USB-to-serial converter to the Micromite. Check that the TX pin on the converter goes to the Micromite’s RX pin and that RX on the converter goes to the Micromite’s TX pin, as illustrated in Fig.3. Loading your program If you prepare your program on a desktop (or laptop) computer, you can transfer it to the Micromite siliconchip.com.au The Micromite works well with a simple solderless breadboard. In this photo it is running the flashing LED example (with the LED connected to pin 15). using either the AUTOSAVE or XMODEM commands. The AUTOSAVE command puts the Micromite into a mode where anything received on the console will be saved to the program memory. This means that you can simply copy the text and paste it into the terminal emulator (eg, Tera Term) which will send it to the Micromite. From the Micromite’s perspective, pasting text into the terminal emulator is the same as if a high speed typist was typing in the program. To terminate the AUTOSAVE command, press CTRL-Z in the terminal emulator (ie, hold CTRL and then press Z) and the Micromite will save the program to flash memory and return to the command prompt. The XMODEM command is a little more complex. It uses the XModem protocol to transfer the data which includes an integrity check. The full command is XMODEM RECEIVE, which instructs the Micromite to look for an XModem connection on the console. After running this command, you then instruct your terminal emulator to send the file using the XModem protocol. When the file has been sent, the Micromite will save it in program memory and return to the command prompt. One of the most convenient methods of creating programs and sending them to the Micromite is to use the MMEDIT software. This program was written by Silicon Chip reader Jim Hiley in Tasmania. It can be installed on Windows or Linux and it allows you to edit your program on your PC and transfer it to the Micromite for testing with a single click. MMEDIT is easy to use with colour-coded text, mouse-based cut and paste and many more features such as bookmarks and automatic indenting. Because the program runs on your PC, you can save and load your programs to and from the computer’s hard disk. It can be downloaded from Jim’s website at: www.c-com.com.au/ MMedit.htm It is free, although he would appreciate a small donation. The Micromite also has its own built-in editor. This relies on you using a terminal emulator that is VT100 compatible (eg, Tera Term) on your desktop computer and to invoke it you use the EDIT command. If you are used to an editor like Notepad in Windows, you will find that the operation of this editor is familiar. The arrow keys will move your cursor around in the text and the other keys on your keyboard will do what their titles suggest. The editor is a very easy method of developing a program. With it, you can write your program on the Micromite then save and run it from within the editor. If your program should stop with an error, you can jump back into the editor again with the cursor positioned at the line that caused the error. As a result the edit/ run/edit cycle is very fast. February 2017  23 Normally, either the DO portion or the LOOP portion will have a condition attached that will tell MMBasic when to terminate the loop but in this case, there is no terminating condition, so the program will loop forever. This introduces another subject – how do you stop something like this when it is running? The answer is that you use the CTRL-C sequence on the console, which is done by holding down the CTRL key when pressing the C key. This is called the break key or character. When you type this on the console’s input, it will interrupt whatever program is running and immediately return control to the command prompt. The PRINT command One of the most frequently used commands in the BASIC language is the PRINT command. Its job is simply to display something on the console. This is commonly used to tell you how your program is running (and can help to find bugs) and the displayed message can be something simple, like “Pump running” or “Total Flow: 23 litres”. In its simplest form, the PRINT command will just print whatever follows it. So, for example: PRINT 54 Will display the number 54 on the console, followed by a new line (ie, so that the next print command will display its output below). The data to be printed can consist of “expressions”, which refers to something that needs to be calculated. We will cover expressions in more detail later but as an example, consider the following: PRINT 5*(9+2) This will print the number 55 (“*” means multiply; “+” obviously means addition). The following program illustrates the use of the PRINT command. It will measure the voltage on pin 4 of the Micromite and display the reading on the console repeatedly, once per second: SETPIN 4, AIN DO PRINT PIN(4) PAUSE 1000 LOOP This program is similar to our LED 24  Silicon Chip flasher but in this case, we have configured pin 4 to be an analog input with the “SETPIN 4, AIN” command. To read the voltage on the configured pin you just use the “PIN(4)” function to get the voltage, which the “PRINT” command will then display on the console. You can test this program by connecting various 1.5V cells between pin 4 and GND (positive end to pin 4) and noting how the reading will change. Congratulations, you have built a digital voltmeter with five lines of BASIC code! You can also use the PIN() function to read the state of a digital, frequency, period or counter input. Note that for a pin configured as an analog input, MMBasic returns the value in volts but it assumes the power supply rail is exactly 3.3V, as this is used for the reference input to the analog-to-digital converter. If your power supply is not exactly 3.3V, the returned value will have to be adjusted as shown later in this tutorial. Variables Before we go much further, we need to define what a “variable” is as they are fundamental to the operation of most computer languages, including BASIC. A variable is simply a place to store an item of data (ie, its value) for later use. Variables can be any one of three types. The most common is a floating point (decimal) number and this is the default if the variable type is not specified. The other two types are integer (ie, whole number) and string (ie, text) and we will explain them later. 7, 3.45, -99.0, .012 and 120.09 are all valid floating point numbers. “Floating” refers to the fact that the decimal point does not have a fixed number of digits either before or after it. When a number is stored in a variable, the variable can then be used in place of the number itself. It simply represents the last value assigned to it. As a simple example: A=3 B=4 PRINT A + B This will display the number 7. In this case, “A” and “B” are variables and MMBasic used their current values in evaluating the expression after the PRINT statement. BASIC will automatically create a variable when it first encounters it, so the statement “A = 3” both creates a floating point variable (the default type) with the name “A” and then it assigns it the value 3. The name of a variable must start with a letter, while the remainder of the name can use letters, numbers, underscores or full stops. The name can be up to 32 characters long and the case of the letters used (ie, lower case or upper case [capitals]) is not important. Here are some examples of valid variable names: Total_Count ForeColour temp3 count The IF statement Making decisions is at the core of most computer programs and in the BASIC language, that is usually done with the “IF” statement. This is written almost like an English sentence: IF condition THEN action The condition is usually a comparison such as testing for equality, less than, greater than, etc. For example: IF Temp < 20 THEN HeaterOn “Temp” would be a variable holding the current temperature and HeaterOn refers to a section of the program containing commands which perform the action(s) necessary to turn the heater on (this is called a subroutine and will be explained later). There is a wide range of comparisons that you can use: = equal to < less than > greater than <= less than or equal to >= greater than or equal to <> not equal to These can be combined using “AND” and “OR”, for example: IF Temp > 20 AND Temp < 30 THEN Temp_OK = 1 You can also add an “ELSE” clause which will be executed if the condition tested false. For example, this program will turn on a LED connected to pin 14 if the voltage on pin 4 is more than 2V and turn it off if it is less: SETPIN 4, AIN SETPIN 14, DOUT DO IF PIN(4) > 2.0 THEN PIN(14) = 1 ELSE PIN(14) = 0 LOOP This program will spin at high siliconchip.com.au speed, constantly setting the output high or low but that does not matter because the program has nothing else to do and it means that the LED will react instantly to any change to the voltage on pin 4. Note that in an IF statement like this with an ELSE clause, one of the two commands is always executed but never both. The previous examples use singleline IF statements but you can also use multi-line IF statements for cases where multiple commands need to be executed. They look like this: IF condition THEN TrueAction1 TrueAction2 ... ELSE FalseAction1 FalseAction2 ... ENDIF Generally, the single-line IF statement is used for simple situations while the multi-line version is much easier to understand if the commands required are numerous and/or long. Note that the multi-line version must be terminated with the ENDIF command; this tells MMBasic where the commands associated with the ELSE leg have terminated. You can also have the multi-line IF statement without an ELSE section. For example: IF condition THEN TrueAction1 TrueAction2 ... ENDIF An example of a multi-line IF statement with more than one action is: SETPIN 4, AIN SETPIN 14, DOUT DO IF PIN(4) > 2.0 THEN PIN(14) = 1 PRINT “Voltage high” ELSE PIN(14) = 0 PRINT “Voltage low” ENDIF LOOP Note that in the above example, we indented (added spaces before) each action to make it clearer which part of the IF structure it belonged to. While this is not mandatory it siliconchip.com.au does make a program much easier to understand and is highly recommended. Hence, all our examples have been indented. Remember that after only a few months, a program that you have written will have faded from your mind and will look strange when you pick it up again. Accordingly, you will end up thanking yourself if you indent consistently. Measuring voltages We mentioned measuring voltages previously but there are some details that you need to know before you can properly use this feature. The 28-pin Micromite (as used in the LCD BackPack) has 10 I/O pins that are capable of voltage measurement and the 44-pin Micromite has 13. Naturally, the 64-pin and 100-pin Micromite Plus chips have even more. They are marked as ANALOG on the pin diagrams. Remember that you need to use a command like this to set an I/O pin (number “nn”) to be an analog input: SETPIN nn, AIN The input voltage range is from zero to whatever the supply voltage is (normally 3.3V). Assuming your supply is stable but not exactly 3.3V, you can measure its actual voltage and compensate to give accurate measurements as follows. In this example, let’s say you measure it as exactly 3.17V: PRINT PIN(4) / 3.3 * 3.17 To avoid having to put the supply voltage all over the program, you can set it as a constant variable at the top of your program and then just refer to the constant, like this: CONST SUPPLY_VOLTAGE = 3.17 … PRINT PIN(4) / 3.3 * SUPPLY_ VOLTAGE Taking this concept a step further, if you’re doing a lot of analog measurements, the following will make the code a little simpler and also faster: CONST SVFACT = 3.17 / 3.3 … PRINT PIN(4) * SVFACT To measure voltages greater than the supply voltage, you will need to connect a voltage divider between the voltage to measure, the analog pin and ground. Rather than use precision resistors for this, you can simply apply a known voltage to the divider and get the Micromite to display what it measured on the input (ie, PRINT PIN(4)). Then, if you use a digital voltmeter to measure the actual voltage at the input of the voltage divider, you can scale future readings from that pin to give the correct value by using the following expression: PRINT PIN(nn) * (Vmes / Vmm) Where “Vmes” is the measured input voltage and “Vmm” is the reading returned by the MMBasic PIN() function. This approach will also automatically correct for a supply voltage that is not exactly 3.3V, so you don’t need to do that separately (and yes, you can use a constant variable to simplify this command, as demonstrated above). Note that to retain the accuracy of the reading, the source resistance for an analog input pin needs to be 10kW or less. This means that in most circuits, the bottom resistor in the voltage divider should be no more than 10kW. To measure very small voltages accurately (well under 1V), you may need an amplifier to bring the input voltage into a reasonable range for measurement. Fig.6 shows a typical arrangement using the popular and inexpensive LM324 quad operational amplifier. The LM324 can operate from a single 5V supply (as provided by the Micromite LCD BackPack on CON2) and contains four identical amplifiers in the one low-cost 14-pin package. The gain of this amplifier is determined by the ratio of R2 to R1 plus 1 (ie, R2 ÷ R1 + 1) and using the components in Fig.6, the gain is 101. This number can be used in the BASIC program so that the readings are scaled to represent the input voltage. For example: PRINT PIN(4) / 101 Alternatively, as with the voltage divider, you could just measure the input voltage and pin reading simultaneously and use the ratio to scale future readings. This would also compensate for resistor value and supply voltage tolerances. February 2017  25 Amplifier Gain = 1 + R2 R1 LM324 A OUTPUT 1 A -INPUT 2 A +INPUT 3 1 4 + + 14 D OUTPUT 13 D -INPUT 12 D +INPUT 11 GND 10 C +INPUT V+ 4 B +INPUT 5 B -INPUT 6 9 C -INPUT B OUTPUT 7 8 C OUTPUT + 2 3 + (Top View) DO loops Returning to our example program earlier, it used a “DO LOOP” to repeatedly step through a set of commands which is a common requirement in computer programs. In the example program, the DO LOOP never stopped running (until CTRL-C is pressed). However, it is more common to provide a test which will terminate the loop at some point. For example: count = 0 DO WHILE count < 10 count = count + 1 PRINT count LOOP This program will simply print the numbers from one to ten. The key aspect is the WHILE test which ensures that the program will only keep looping while the value of “count” is less than 10. When the value of count equals or exceeds 10, MMBasic will terminate the loop and continue on with the code after the LOOP command. The conditional test is the same as for the IF command so you can test for equality, less than, greater than and so on. As another example, you might need to delay the start of a program for two seconds to allow external circuitry to settle. This could be done with this loop: DO WHILE TIMER < 2000 LOOP “TIMER” is a built-in MMBasic function which returns the number of milliseconds since the Micromite was powered up. This empty loop will simply “sit there and spin” 26  Silicon Chip With the values shown the gain will be 101 and therefore a 32mV input will result in a full scale reading. 5V POWER 1 + 2 CON2 Input (0-32mV) Fig.6: to measure small voltages you need an amplifier and this shows how to use the LM324 quad op amp. It can operate from a single 5V supply (as provided by the Micromite LCD BackPack on CON2) and contains four identical amplifiers in the one 14-pin package. until the value of TIMER reaches 2000ms, thereby providing the required delay. Note that a similar effect could be achieved with the PAUSE command, however, consider that if you had other commands to run before the loop, the time taken to execute them would be taken into account by this method. Thus this method which would give a faster start-up while still providing the required settling time. An important feature of the above loops is that the test is made before the loop is executed and that in turn means that if the test is initially false, the contents of the loop will not be executed at all, not even once. However, if you do want the loop’s contents to be executed at least once, you can position the test at the end of the loop instead, as follows: DO statement statement LOOP UNTIL condition Micromite 4 3 LM324 2 1 10kΩ Input Pin 11 R2 10kΩ R1 100Ω In this case, the statements within the loop are executed at least once and only then is the condition is tested. Also note that because the keyword “UNTIL” is used, the test is reversed; if it is true the loop will be terminated, otherwise it will be repeatedly executed until the condition does becomes true. This is our previous example rewritten to place the test at the end of the loop: count = 0 DO count = count + 1 PRINT count LOOP UNTIL count = 10 Both forms of the “DO LOOP” do the same thing, so you can use whatever structure fits with the logic that you want to implement and is the most clear to write and interpret. Next month we will continue the tutorial with drawing graphics on an LCD display panel, FOR loops, expressions and much more. SC Getting more information on the Micromite The Micromite is a fully functional computer with a multitude of facilities and the Micromite User Manual which describes it adds up to almost 100 pages. This manual is the ultimate reference for the Micromite and covers everything from the I/O pins through to functions that you might only need in specialised circumstances. It is in PDF format and available for free download from the Silicon Chip website (at www.siliconchip.com.au/ Shop/6/2907) and the author’s website (http://geoffg.net/micromite.html). This tutorial (including the parts to come in future months) will go through many aspects of the BASIC language but it cannot cover everything. For example, many commands have additional features that are only used in special circumstances. So it would be worthwhile downloading the manual and having it handy as you read through the tutorial. That way you can explore the full detail of a command that might interest you. siliconchip.com.au