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The 44-Pin Micromite Introduced in the May & June 2014 issues of SILICON CHIP, the Micromite is an easilyprogrammed microcontroller in a 28-pin DIP package. This month, we present its big brother, the 44-Pin Micromite. It has all the features of the original Micromite but with a much more generous 33 I/O pins. Now there’s no excuse not to use a Micromite in your biggest project. B OASTING A LARGE amount of memory, 19 I/O pins and many other features, our original Micromite was based on a low-cost 28-pin microcontroller loaded with a fully-featured BASIC language interpreter called MMBasic. It’s been an instant hit with readers but its one drawback was the limited number of I/O pins. For example, if your project used a keypad and an LCD, you immediately lost 13 pins just supporting those two devices. This left you with only six spare I/O pins for other duties. This is why we have ported MM­ Basic to a 44-pin variant of the same PIC32 microcontroller. This version of the Micromite has 33 I/O pins that • • • • • • • can be controlled via MMBasic, so you would still have 20 pins free after implementing a keypad and LCD. And that is plenty for connecting distance sensors, servos, IR remote control and whatever else that you might need to finish your project. The only possible downside is that the 44-pin chip is a surface-mount package. However that’s not a real obstacle as we will show you how to solder it to an adaptor board which can then be easily connected to external devices via header pins. We will also describe how to install the 44-Pin Micromite, a USB interface and a power supply on a single PCB that’s only a little larger than a regular 40-pin DIL IC. Micromite Module: Main Features 32-bit microcontroller with on-board BASIC interpreter and 42kB memory for program plus variables 33 I/O pins including 13 that are analog capable and 17 that are 5V tolerant Small form factor, 68 x 22mm I/O pins have a 0.1-inch pitch with 0.7-inch track (similar to a 40-pin DIL package) Integrated USB-to-serial bridge for the console Integrated 3.3V voltage regulator for the microcontroller and external circuitry Power requirement: 5V at 38mA plus the current drawn from the I/O pins 42  Silicon Chip The Micromite Module transforms the 44-pin Micromite (which is a surface mount chip) into a plug-in module that’s only a little larger than a conventional 44-pin DIL IC. On the top of the module (from bottom left) are the USB connector for the programming console, a jumper for selecting the power source, a green power LED, the Micromite chip, a programming header (if you ever need to upgrade the version of MMBasic) and a reset button. By GEOFF GRAHAM The 44-Pin Micromite has all the features of the original 28-pin variant. This includes 42kB of memory for your program and variables combined, floating point calculations, extensive string handling, multi-dimensional arrays and easy control of I/O. Also, like the 28-pin version, this new version has support for IR remote control, distance measuring sensors, temperature sensors and much more. We won’t repeat the description of the original Micromite here. Instead, if you missed the original articles, it would be well worth ordering the May and June 2014 issues from SILICON CHIP (eg, via the website). Alternatively, you can purchase on-line access to these issues. The only discernible difference between this version and the 28-pin version is that you now have 33 I/O pins at your beck and call. This includes 13 pins that can be used to measure voltage and 17 pins that are 5V tolerant. Fig.1 shows the pin-outs of the 44pin Micromite and the capabilities of each I/O pin. As with the 28-pin version, it would be worth copying and laminating this diagram as you will find yourself referring to it quite siliconchip.com.au 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 44-PIN MICROMITE MODULE DIGITAL / INT / 5V / COUNT / I2 C DATA DIGITAL / INT / 5V DIGITAL / INT / 5V DIGITAL / INT / 5V DIGITAL / INT / 5V GROUND CAPACITOR (+) TO GROUND COM1: TRANSMIT / 5V / INT / DIGITAL COM1: RECEIVE / 5V / INT / DIGITAL DIGITAL / INT / ANALOG PWM2B / DIGITAL / ANALOG 5V / DIGITAL 5V / DIGITAL ANALOG / DIGITAL / SPI CLOCK ANALOG / DIGITAL / PWM2A ANALOG GROUND ANALOG POWER (+2.3 – +3.6V) RESET ANALOG / DIGITAL DIGITAL /ANALOG / SPI OUT (MOSI) ANALOG / DIGITAL / PWM1A ANALOG / DIGITAL / PWM1B 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 I2 C CLOCK / DIGITAL / 5V / COUNT DIGITAL / 5V / COUNT / WAKEUP/ IR DIGITAL / 5V / COUNT SPI IN (MISO) / 5V / DIGITAL POWER (+2.3 – +3.6V) GROUND 5V / DIGITAL 5V / DIGITAL DIGITAL 5V / DIGITAL CONSOLE Rx (DATA IN) CONSOLE Tx (DATA OUT) 5V / DIGITAL COM2: RECEIVE / DIGITAL COM2: TRANSMIT / DIGITAL GROUND POWER (+2.3 – +3.6V) ANALOG / DIGITAL ANALOG / DIGITAL ANALOG / DIGITAL COM1: ENABLE / DIGITAL / ANALOG PWM1C / DIGITAL / ANALOG Fig.1: these are the connections to the 44-pin Micromite Module and the functions available on each pin. The pins marked with colour labels are used for power etc and cannot be used for general I/O while the other pins can be used for one or more of the following functions: • • • • • • • • • • • ANALOG: these pins can be used to measure voltage (AIN). DIGITAL: can be used for digital I/O such as digital input (DIN), digital output (DOUT) and open collector output (OOUT). INT: can be used to generate an interrupt (INTH, INTL and INTB). COUNT: can be used to measure frequency (FIN), period (PIN) or counting (CIN). 5V: these pins can be connected to 5V circuits. All other I/O pins are strictly 3.3V maximum. COM xxx: these are used for serial communications. I2C xxx: these are used for I2C communications. SPI xxx: if SPI is enabled these pins will be used for SPI I/O. PWM xxx: PWM or SERVO output (see the PWM and SERVO commands). IR: this can be used to receive signals from an infrared remote control (see the IR command). WAKEUP: this pin can be used to wake the CPU from a sleep (see the CPU SLEEP command). Note: the mnemonics in brackets are the modes used in the SETPIN command. often when designing with the 44-pin Micromite. Suitable microcontrollers There are two 44-pin PIC32 microcontroller versions that will work with the Micromite firmware. The recommended chip is the PIC32MX150F128D-50I/PT which is rated at a top clock speed of 50MHz. The alternative is the PIC32MX150F128DI/PT which is rated at 40MHz. Either chip can be purchased direct from the Microchip Direct website or from the usual distributors (DigiKey, Mouser, element14, RS Components, etc). The Micromite will start up with its clock speed set to 40MHz but this can be increased to 48MHz under program control. All the 40MHz chips that we have tested worked OK at 48MHz but siliconchip.com.au this isn’t guaranteed. Regardless, the slower chip can be an option if you are unable to source the faster chip or you don’t need that extra ounce of speed. The technical details of the 44-pin chip (supply voltage, drive capability, etc) are the same as for the 28-pin chip. Adaptor board One way of getting started with the 44-pin Micromite is to solder it to an adaptor board. These take the 44 pins of the chip and distribute them to header pins on a 0.1-inch pitch. From there, you can attach jumper leads for testing or even install the chip as a plug in module into your final circuit. If you search the Internet for “44 pin TQFP Adaptor” you will find many examples. For example, Futur­ lec has these adaptors (Part Code: 44PINTQFP) for $A1.26 each. We’ll provide some hints on soldering the chip to this adaptor board later – it’s not as daunting as you may believe. If you purchase a blank chip, it can be programmed with the MMBasic firmware using the circuit shown in Fig.2. Note that you need a decoupling capacitor from pin 7 (Vcap) to ground. This should be either a 10µF multi­layer ceramic or a 47µF tantalum. Don’t leave this capacitor out or substitute an electrolytic because the chip will fail to start or even worse, you could have intermittent issues. The Micromite Module Rather than use the adaptor board, a better option is to build our Micromite Module. It’s a PCB measuring just 68 x 22mm and includes the Micromite August 2014  43 17 28 +2.3V – 3.6V 25mA (FROM PICkit 3) 40 10k PICkit 3 ICSP CON. MCLR Vcc GND PGD PCC NC 1 18 44–PIN MICROMITE 2 3 4 21 5 22 7 6 47 µF TANTALUM OR 10 µF CERAMIC 6 16 29 39 LOADING FIRMWARE Fig.2: here’s how to connect a 44-pin PIC32 microcontroller to a PICkit 3 programmer to load the MMBasic firmware. Once it’s wired up, you use MPLAB IPE (free from Microchip) to program the device. chip, a voltage regulator, a USB interface for the console and all the other parts required to turn the 44-pin Micromite into a complete computer module. This board uses a similar pin width as a regular 44-pin DIL IC and is only a little longer, so you can treat the completed module as a plug-in component, similar to a large IC. You could plug it into a solderless breadboard for experimenting and then move it to your final circuit which could be on a custom-designed PCB or even built on stripboard. By the way, the Micromite Module was designed by Phil Boyce in the United Kingdom. Phil was one of our hard-working beta testers for the Micromite firmware and he was so taken with the potential of the 44-pin Micromite that he designed this board to accommodate it. You can purchase blank PCBs from Phil’s website (www. micromite.org) or from the SILICON CHIP website. Fully assembled and tested boards are also available direct from Phil and parts and kits are available from SILICON CHIP (see panel). Main features The most useful feature of the Micromite Module is that it incorporates a USB interface for the console, so you don’t need a USB-to-serial bridge. You simply plug a USB cable directly into the module and (using either a PC or a Mac) immediately begin to write and edit your BASIC program. The PCB includes two LEDs to indicate activity on the console – red for received data from the PC to the Micromite Module and green for transmit. These are handy when you are setting up the drivers on the PC, as you can One method of experimenting with the 44-pin Micromite is to mount it on an adaptor board which brings all the chip’s connections to header pins with a 0.1-inch pitch. This makes it easy to use the Micromite with a breadboard to develop the final circuit. Adaptor boards can be easily found on the Internet for less than $2.00. 44  Silicon Chip see if your keystrokes actually reach the Micromite. The module also includes a regulator which accepts either the USB 5V supply or an external 5V supply and regulates it down to 3.3V for the Micromite chip. A second green LED on the top of the board indicates a working 3.3V supply. Both the 5V and 3.3V supplies are also available on several header pins and in the case of the 3.3V supply, can provide up to 100mA for other circuitry. The Micromite chip’s connections are all brought out to header pins along the sides of the board. This enables you to build a “short form” version of the board which need only to be populated with the 44-pin Micromite chip and a few decoupling capacitors. This will then act the same as the 44-pin TQFP adaptor described earlier, the difference being that the you can later add the other features of the Micromite Module if you wish. Because the I/O pin numbers in MMBasic are the same as the actual pin numbers on the chip (and because all the chip’s connections are brought out to header pins), the pin numbering scheme is simple to follow. For example, pin 15 in MMBasic is the same as pin 15 on the chip which is also the same as pin 15 on the Micromite Module. This also means that you can simply follow Fig.1 when you are connecting the Micromite Module into a circuit and writing programs for it. A jumper on the top of the PCB connects the USB 5V supply to the regulator. This means that if you wish to power the Micromite Module via USB, you should place a jumper on these pins. Alternatively, you can power the module from an external 5V supply (via the header pins along the edge of the board), in which case the jumper must be removed. The PCB also includes an ICSP (InCircuit Serial Programmer) header (CON2) so that you can update the firmware using a programmer such as the PICkit 3. Another useful feature is reset button S1. Pressing this pulls MCLR-bar of IC1 to ground and restarts the Micromite, which is far more convenient than cycling the power (which would also close the USB connection to your computer). Circuit details Fig.3 shows the complete circuit siliconchip.com.au USE USB POWER 2 REG1: LF33ABDT +5V 1 20 CON3 USB 19 16 D– 1 2 3 4 5 D+ 15 13 12 Vcc PWREN RESET CTS USBDM USB DP RTS DTR TXDEN DCD IC2 FT2 3 2 RL 17 3V3OUT SSOP 4 SLEEP RI TXLED VCCIO 27 28 100nF RXLED OSCI TXD RXD OSCO A 14 LED1 9 7 18 21 47 µF 330Ω 330Ω 6 22 1 5 1– MCLR 2–Vcc 100nF 100nF 3–GND 100nF TO IC1 PIN 34 TO IC1 PIN 33 17 AVDD 26 4 1 RB9/RPB9/SDA1/PMD3 2 RC6 /RPC6/PMA1 3 RC7 /RPC7/PMA0 4 5 5 3 6 VCAP VDD 8 RC8/RPC8/PMA5 RC9/RPC9/PMA6 10 12 RA10/PMA10/TMS/PGED4 14 15 RPB7/PMD5/RB7 PGEC3/RPB6/PMD6/RB6 PGED3/RPB5/PMD7/RB5 S1 RESET RPC5/PMA3/RC5 RPC4/PMA4/RC4 RPC3/RC3 TDI/RPA9/PMA9/RA9 44 43 44 38 37 42 41 PIN 1 IC2 18 MCLR 19 AN8/RPC2/RC2 19 RA0 /AN 0 /VREF+ 20 20 AN7/RPC1/RC1 22 36 35 34 33 32 31 30 30 29 PG_DATA PG_CLK * AVSS 16 VSS 6 +3.3V 27 26 VSS 39 INSTALL JP1 FOR USB POWER. REMOVE JP1 FOR EXTERNAL POWER VIA CON1. 44-PIN MICROMITE MODULE 27 25 24 AN5/RPB3/RB3 VSS 29 28 26 AN6/RPC0/RC0 PGEC1/AN3/RPB1 /RB1 39 37 36 35 25 24 23 AN4/RPB2/RB2 7 VCAP RA1/AN1/VREF– 21 PGED1/AN 2 /RPB 0/RB0 22 21 40 38 PIN 5 IC2 +3.3V CON5 43 42 41 34 RXD 33 TXD SOSCI/RPB4/RB4 32 TDO/RPA8/PMA8/RA8 31 OSC1/CLKI/RPA2/RA2 6–NC 18 +3.3V OSC2/CLKO/RPA3/RA3 RB15/RPB15/AN9 16 5–PCC SOSCO/RPA4/RA4 13 RA7/PMA7/TCK 14 RB1 4 /RPB1 4 /AN 10 15 13 RPB8/PMD4/RB8 RB10/RPB10/PMD2/PGED2 11 RB1 3 /RPB1 3 /AN 11 12 11 4–PGD PG_CLK MCLR VDD IC1 PIC32MX150PIC3 2 MX150F128D RB12/PMD0/AN12 PG_DATA 40 28 9 RB11/RPB11/PMD1/PGEC2 10 9 17 CON2 ICSP +3.3V 23 2 SC 10k 100Ω 1 20 1 4 GND λ LED3 CON4 8 +3.3V K MCLR 7 +5V JP2 LED ENABLE A K 330Ω 10 CON1 +3.3V λ LED2 K 3 GND 100nF A λ 11 AGND GND GND GND TEST 25 OUT IN θ JP1 * F1 PTC (SMD) 23 TO PIN 7 CON4 47 µF 16V LF33ABDT LEDS TAB (GND) K IN OUT A Fig.3: the complete circuit for the Micromite Module. IC1 is the 44-pin PIC32 chip programmed with MMBasic, while IC2 (an FT232RL USB-to-serial converter) provides the USB interface. Power can come either from the USB host (JP1 installed) or from an external source via CON1 (JP1 out). for the Micromite Module. The USB interface is provided by IC2 which is an FT232RL USB-to-serial converter made by Future Technology Devices (FTDI). This chip is used in many USB-to-serial converters and has good driver support for all operating systems. In fact, many operating systems come with the required drivers pre-installed. As shown, the D+ and D- lines from the USB connector (CON3) are consiliconchip.com.au nected to pins 15 & 16 of IC2 respectively. This is then translated to a bidirectional TTL serial interface at pins 1 (TxD, transmit) and 5 (RxD, receive). These are in turn connected to the serial interface of the Micromite chip (IC1), ie, pins 34 & 33 respectively. The FT232RL also directly drives LED1 (red) and LED2 (green) which indicate activity on the console. The 5V rail for the FT232RL (IC2) and the 3.3V regulator (REG1) can come from an external source (via CON1) or from the USB host (ie, a PC). In the latter case, jumper JP1 must be installed and F1, which is a PTC resettable fuse, protects the host computer from an accidental short on the 5V output pins. Note that JP1 must not be installed if an external 5V supply is connected to CON1. REG1 is a fixed voltage, low-dropout regulator which supplies the MicroAugust 2014  45 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 42 CON1 K CON2 ICSP IC1 A LED3 JP2 1 PIC32MX150F –128D 1 S1 K 1 2 3 4 LED2 17 18 19 20 21 22 A A LED1 JP1 5 6 7 8 9 10 11 12 13 14 15 16 K USB POWER 23 USB mini CON3 GND 5V 44 43 TOP OF MODULE 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 9 8 + 47 µF 330Ω 330Ω 100nF 15 14 13 12 11 10 22 21 20 19 18 17 16 100nF IC2 FT232RL LF33ABDT 10k 100Ω F REG1 100nF 100nF F1 PTC 330Ω + 5 4 3 2 1 47 µF 1 100nF 7 6 23 24 25 26 27 28 UNDERSIDE OF MODULE Fig.4: you can purchase a kit of parts and assemble the Micromite Module yourself as shown here. That way you can use the module as just a carrier for the Micromite chip or you can fully populate it with all the parts, including the USB interface and the voltage regulator. mite chip (IC1) and the green power LED (LED3). This LED can be disabled by leaving the solder pads at JP2 open. This can be important if you are trying to reduce the current consumption and every milliamp is important. The remaining parts in the circuit are PIC32 microcontroller IC1 (programmed with MMBasic), a few decoupling capacitors, ICSP header CON2 and two single-row 22-pin headers CON4 & CON5. Building it Many of the parts used in this project, including the two ICs and the regulator, are surface-mount devices. In addition, parts are mounted on both Fig.5: the terminal emulator that you use to connect to the Micromite Module (via USB) should be set to 38400 baud, eight bits data, no parity and one stop bit. This screen grab shows what the set-up dialog in Tera Term should look like with the correct values entered. Note that your port number will almost certainly be different to that shown because it will change with the physical USB port. 46  Silicon Chip sides of the PCB. This was done to reduce its size but it is still a relatively painless job to assemble. Alternatively, a fully-assembled and tested Micromite Module is also available if you don’t want to build it yourself (see the accompanying panel: “Where To Buy the Parts”). We have described how surfacemount devices are soldered many times in the past, so we will only give the basics here. You need to start with a good SMD soldering flux (eg, Altronics H1650A or Jaycar NS3036) and a temperature-controlled soldering iron with a small flat tip (not needle-point). A x10 magnifier (preferably a magnifying lamp) is also useful, as is a pair of fine-tipped tweezers. With SMD soldering you mostly carry the solder to the joint on the iron’s tip and because of that, you need a tip with sufficient width (eg, a 0.8mm chisel tip) to hold the solder. You also need to liberally apply the flux to the joint beforehand as any flux in your solder will have boiled away before it reaches the joint. The Micromite chip has a forgiving 0.8mm pin spacing and is therefore relatively easy to solder. Start by applying plenty of flux to the pads on the PCB, then place the IC on the board and nudge it into position. While doing this make sure that the dot marking pin 1 on the chip matches the corresponding dot on the PCB. Once it’s in place, hold the chip down with tweezers or a matchstick and tack-solder one pin. That done, check that the chip’s alignment is still correct then solder the diagonally opposite pin. After that it’s just a case of applying more flux to all the pins and soldering them one by one. Don’t forget to return to the first pin and resolder it. The secret is to use only a very small amount of solder on the iron’s tip and gently touch it where each pin meets the PCB. Provided you’ve applied plenty of flux, the solder will magically flow around the pin, making a perfect joint. If you have too much solder on the iron, the result will be a solder blob joining two or more pins. If that happens, reduce the amount of solder on the iron and carry on. It’s then just a matter of going back and removing any excess solder (eg, solder shorts between pins) using solder wick. Remember, flux is your friend and too much solder your enemy. If you just want to use the PCB as a carrier for the Micromite chip, you only need to install the chip itself, the 47µF capacitor connected to pin 7 (Vcap) and the three 100nF decoupling capacitors on pins 17, 28 & 40. The SMD capacitors are easy to install: in each case, apply plenty of flux and tack solder one end, then solder the other before returning to the first to complete the job. Alternatively, if you wish to assemble the full board, you should now move on to IC2, REG1 and the other components. Other than the header pins, which should be left until last, the order of assembly is not important. Note that IC2 (the FT232RL) has a finer pitch than IC1 at 0.65mm but it is still siliconchip.com.au electronics design & assembly expo Design, Develop, Manufacture with the Latest Solutions! In the fast paced world of electronics you need to see, test and compare the latest equipment, products and solutions for manufacture and systems development. electronics & assembly expo Showcasing new and design future technologies in electronics Register Online Now www.electronex.com.au Knowledge is Power Make New Connections SMCBA CONFERENCE The Electronics Design and Manufacture Conference delivers the latest information on a host of topics. • Australian & NZ based suppliers with the latest ideas and innovations • New product, system & component technology releases at the show • Australia’s largest dedicated electronics industry event Mono Version • NEW technologies to improve design and manufacturing performance • Meet all the experts with local supply solutions electronics design & assembly expo The last conference in Sydney attracted over 200 delegates and featured an impressive list of international presenters. For conference details please visit www.smcba.asn.au Australian Technology Park - Sydney 10-11 September 2014 www.electronex.com.au siliconchip.com.au August 2014  47 Parts List: 44-Pin Micromite Module 1 double-sided PCB, code 24108141, 68 x 22mm 1 USB Mini-B SMD socket (5-pin) (Altronics P1308, Rapid 24-0357) 1 PCB-mount SPST tactile switch (right angle, red) (RS Components 7455182) 2 22-pin single row headers, 0.1-inch 1 5-pin single row header, 0.1-inch 1 3-pin single row header, 0.1-inch 1 2-pin single row header, 0.1-inch Semiconductors 1 Microchip PIC32MX150F128D-50I/ PT microcontroller (SMD: TQFP) programmed with 2410814A.hex (IC1) 1 STMicroelectronics LF33ABDT voltage regulator (SMD:DPAK) (IC2) 1 FTDI FT232RL USB-to-Serial UART (SMD:SSOP-28) (IC3) 1 red LED (SMD:0805) (LED1) 2 green LEDs (SMD:0805) (LED2, LED3) 1 PTC resettable poly-fuse (SMD:1206) (Littelfuse 1206L050YR) Capacitors 2 47µF 6.3V tantalum, ESR <1Ω (SMD:1210) 5 100nF ceramic (SMD:1206) Resistors 1 10kΩ (SMD: 1206) 1 330Ω (SMD: 0805) 2 330Ω (SMD: 1206) 1 100Ω (SMD: 1206) a straightforward soldering job. Don’t forget to short the two pads marked JP2 with a blob of solder if you want power indicator LED3 to operate. Programming the PIC32 As mentioned, if you have a blank microntroller chip, you will need to program it with the MMBasic firmware. The firmware for the 44-pin chip Fig.6: when you have connect­ ed to the Micromite, this is the message that you will see when the reset button is pressed. It shows that the Micromite is working correctly and you can start thinking of the program that you need to write to bring your project to life. is different to the 28-pin chip version, so be sure to download the correct file. This is labelled as “44-pin” and can be downloaded from the SILICON CHIP website along with an addendum to the user manual covering the 44-pin chip. To program the microcontroller, you will need a programmer such as the PICkit 3. This should be connected to the ICSP connector which is on the top of the board. Using MPLAB IPE (part of MPLAB X from Microchip), it only takes a few seconds to load MMBasic onto the chip and turn it into a Micromite. Once that has been done, you will not need to use the programmer again unless you decide to upgrade MM­Basic to a newer version at a later date. Getting it going Using the Micromite Module is simplicity itself. First, decide if you are going to use USB or external power and configure jumper JP1 accordingly (ie, install JP1 for USB power; leave it out for external power). That done, connect the Micromite Module to a USB port on your computer and check that the green power LED lights when power is applied (provided you’ve shorted the JP2 solder pads). In most cases, the operating system will already have the correct drivers installed and the module will be recognised immediately. If not, you can download the driver from the FTDI website at http://www.ftdichip.com/ Drivers/VCP.htm Where To Buy The Parts Various forms of the Micromite Module can be purchased from Phil Boyce’s website at www.micromite.org   The options include a blank PCB (£3), a stripped-down 44-Pin Micromite Light Module (£10) and a fully-assembled 44-Pin Micromite Module (£23.50). Check his website for details and many other Micromite add-ons. Alternatively, all the parts (including the PCB and a pre-programmed 44-pin Micromite chip) can be purchased as a kit for $A35 including GST (plus p&p) from the SILICON CHIP Online Shop. The PCB and pre-programmed Micromite chip are also available separately. MMBasic and a User Manual are also available on the SILICON CHIP website (free of charge). 48  Silicon Chip With the correct driver installed, the Micromite Module will appear as a “USB Serial Port” in the device listing on your computer. You then need to run a VT100 compatible terminal emulator such as Tera Term (for Windows) and connect to the new communications port created by the Micromite Module. Now, when you press return on the terminal emulator, you should see a flash from the red LED (LED1, receive data) on the board and a flash from the green LED (LED2, transmit data) as the Micromite responds with the command prompt (ie, >). If you don’t see the red LED flash then something must be wrong with either the FT232RL chip (IC2) or the configuration of your computer. If you get a red flash when you press return but no green flash, the fault probably lies with the Micromite chip (eg, has it been programmed with the correct firmware?). Once you have both LEDs flashing correctly and the command prompt showing on your terminal emulator, you are ready to go. You can now enter and run your first program on the 44pin Micromite. Firmware updates For firmware updates and handy hints, check the author’s website at geoffg.net/terminal.html Firmware updates will also be posted on the SILICON CHIP website at www.siliconchip. com.au Finally, you should also check out the Back Shed forum at www.thebackshed.com/forum/forum_topics. asp?FID=16 It has many Maximite and Micromite enthusiasts who will be only SC too happy to help beginners. Acknowledgement The author would like to thank the more than 40 dedicated beta testers who worked for over two months to ensure that the Micromite software is as bug-free as possible. siliconchip.com.au