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MAL-4: Microcontroller Aid for Learning; Pt.3 All the parts for the MAL-4 microcontroller are mounted on a double-sided PC board, so the assembly is straightforward. All you have to do is follow the step-by-step instructions. By BARRY ROZEMA Numerous hours were spent designing, prototyping and programming the MAL-4 microcontroller kit but all this time will have been in vain if you do not take considerable care in the construction. At the very least, read the following instructions thoroughly before starting assembly. If you are an experienced construc46 SILICON CHIP tor, then the steps may be used as a guide on~y. However, if you don't have much experience, then the following steps should be adhered to rigidly. Step 1: check the supplied components against the parts list. Contact the kit supplier immediately if there are any missing components. Step 2: check the copper tracks on the PC board by holding it in front of a strong light. You should spend at least half an hour inspecting the board for breaks, tracks shorted together and holes not drilled. It is easier to spot faults on a bare board than it is on a fully assembled board. Step 3: solder the IC sockets into place. Each IC position has pin 1 marked on the PC board and care should be taken to orient each IC socket accordingly. Note: some readers may wish to use the more expensive ZIF (Zero Insertion Force) sockets for Ul & UZ. Step 4: solder all resistors into place, as indicated on the board and on the wiring diagram (Fig.2). Bend the leads E.S.D. Jf<SRDZEMAYI.'i'll Fig.3: parts layout for the MAL-4 microcontroller. Note that only the bottom layer of the board is shown, which is why some tracks appear to end in mid-air. Follow the instructions in the text when installing the parts on the board. at right angles with long-nosed pliers and fit each resistor with its tolerance band towards the righthand or bottom edge of the board (this will make checking easier later on). Trim the excess wire from the soldered joints on the back of the board. Step 5: solder the capacitors into place, making sure that all tantalum and electrolytic capacitors are correctly oriented (the positive lead is marked by a plus sign on the PC board). Trim the excess wire from the soldered joints on the back of the board. Step 6: install the light emitting diodes (LEDl-18). Most LEDs have a flat spot on their base to mark the cathode (K) lead and this should go to the negative sign, as marked on the PC board. If the cathode is not marked, the cathode lead is the shorter of the two. Note that LED 2 should be a high intensity type. Step 7: install diodes D1-D5 & the bridge rectifier BR1. The cathode terminal is marked by the bar in the diode outline on the PC board. Check that the bridge rectifier is correctly oriented; ie, that its plus and minus pins go to corresponding pads on the PC board. Step 8: install transistors Q1-Q3. Ql and QZ have their base terminal towards the righthand side of the board, while Q3's base terminal is towards the bottom of the board. Step 9: install potentiometers VR1 and VRZ. The PC board has been designed to accept potentiometers with different "footprints". When installing each potentiometer, connect its wiper terminal to one of the two lower holes in the footprint on the board. Step 10: fit the four fuse clips. Note that some brands of fuse clips must be oriented correctly to allow the fuse to fit between them. Fit the two 1A fuses. Step 11: install the 2MHz crystal. Note that this crystal should lie flat on the PC board, as shown in Fig.3. Step 12: install SIP resistors RP1RP3. Pin 1 is marked on each resistor pack and this must be aligned with the pin 1 marking on the PC board. Step 13: install plugs PL1 and PLZ. These should both be mounted with their long pins pointing up. Step 14: install linking terminals LNK1-LNK3 with their long pins facing up and fit the shorting straps. In each case, the shorting strap should be fitted to the upper position (position 1). Step 15: solder the display socket to the PC board. The type of display that has been supplied will govern the type of socket and its position. Display 1 has a 14-pin DIP plug & socket, while Display 2 has a 14-pin SIP plug & socket. After fitting the socket, fit the plug to the underside of the display (the pins are soldered on the top of the display board). Don't plug the display in yet. Step 16: install 5V regulator U9 and its heatsink. To do this, first align the heatsink and regulator assembly with the board by bending the pins of the regulator through 90°. Once the correct location has been found, apply a light film of heatsinking paste to the back of the regulator, then bolt the assembly to the PC board using three 3mm screws, nuts and washers (nuts on the top of the heats ink). Solder the regulator leads and trim away the excess lead lengths. Step 17: install the rightangle PCmount DIN socket (IBM type), then FEBRUARY 1993 47 Table 1: Input/Output Program Address Data · 0030 B6 00 0032 B7 01 0034 BC 30 Table 2: Tone Generator Address Data 0040 B6 00 0042 CD 14 A1 0045 1F 02 0047 B600 0049 CD 14 A1 004C 1E 02 004E BC40 install the 8-way screw connector. Make sure that the wire entry side of the screw connector faces the lefthand edge of the board. Step 18: install the three PC-mount toggle switches (Sl, S2 & S3). Note: if you do not wish to use the switches, Sl must be replaced with a wire link. This link should go betweeri the two lower pads of the Sl terminals. Step 19: install the PC-mount pushbutton switches (KEY5 & KEY6). Careful inspection of the switch pinouts and the PC board is necessary to obtain the correct orientation. Try to fit the switches so that the "RESET" and "IRQ" prinL markings on Lhe board are visible (see the notes supplied with the kit). Step 20: install the keypad. The MAL-4 can accommodate several types of keypads: (1). Keypad 1: 16-key (4 x 4) x-y,, 9pin. (2). Keypad 2: 24-key (3 x 8) x-y, 11pin. (3) . Other: up to 32 keys, hard wired. If you purchased a complete kit, refer to the notes supplied with the kit. If you want to use a socket with the keypad, this should now be fitted to the PC board. The keypad is then fitted by plugging it into the socket or by soldering it directly to the board. If you use Keypad 2, then skip the next step. Step 21: install PC-mount pushbutton switches KEY2, KEY3 & KEY4. As before, careful inspection of the switch 48 SILICON CHIP pin outs and the PC board is necessary to ensure the correct orientation. Try to fit the switches so that the titles on the overlay are visible. Step 22: install the two 8-way DIP switches by plugging them into their sockets. These switches should be oriented so that the "ON" position is towards the bottom of the PC board. This will set the switches so that "up" is high and "down" is low. Step 23: apply 9V AC to the power connector terminals labelled" AC", or 12V DC between the terminal marked +12 and GND (your supply should have a current capability of at least 500mA). Operate switch Sl and check that the power LED (LED 1) lights. Now measure the voltage on the +5 terminal of the screw connector block - it should be between 4.75V and 5.25V. If all is well, disconnect the AC and continue. If not, remedy the fault(s) before moving on to the next step. Step 24: install ICs U3-U8 by plugging them into their sockets. Make sure that each one is correctly oriented (double check this) before applying power. Step 25: apply 9V AC to the power connector terminals, switch on and re-check the +5 terminal on the power connector strip (4.75-5.25V). Check the temperature of the ICs by feeling them with your finger - all should be cool. If all is well, disconnect the AC and continue. If not, remedy the fault(s) before proceeding. Step 26: install the display & the pre-programmed MCU (U2) by plugging them into their sockets. Step 27: re-apply power, check the temperature of the MCU (U2), and check for signs of distress. Re-check the +5V terminal on the power connector. If this voltage is low, switch off immediately and remedy the fault. If all is well, there should be a message on the LCD (note: contrast pot VR1 may need to be adjusted). This message will read "* * * WARNING! *** RAM POWER FAIL" if you have no battery back-up supply, or "M.A.L. Vers 4.XX Enter Mode ... " if you do. If the display reads "* * * WARNING! * * * RAM POWER FAIL" then press the reset key and the display will read "M.A.L. Vers 4.XX Enter Mode ... " The construction of the MAL-4 board is now complete. The next step is check that the various functions built into the unit are working cor- rectly. Assuming that you get the messages described in step 2 7 on the display, you should now perform each of the tests described below. Keypad test (mode 7) Step 1: to enter this mode, press the "7" key at the "M.A.L. Vers 4.XX" prompt. The display should now show "KVAL - KYBIN -" on the first line and "MAL Keyboard TST" on the second line. Step 2: press any keypad key. The display should show the KEYVALUE (the order in which the keys are scanned) and the KEYBINARY (ie; the assigned binary value for a given key). Step 3: press the RESET or IRQ switch key to leave mode "7". This will display the "M.A.L. Vers 4.XX" prompt again. Display test (mode 8) Step 1: press the "8" key at the "M.A.L. Vers 4.XX" prompt. The display should rotate all its characters to the right from a flashing cursor. Step 2: press the RESET or IRQ key to leave mode "8" and display the "M.A.L. Vers 4.XX" prompt again. Keyboard.test (mode D) Step 1: set the DIP switches on PORT D (DIP SW2) as shown below: DIP SW2 7 X E 5 4 3 2 1 0 on on off off off off off Step 2: plug an IBM XT compatible keyboard into the DIN socket on the lefthand side of the board. Step 3: press the "D" key from "M.A.L. Vers 4.XX" prompt. The display should now show "Keyboard Data" on the first line, while the second line will be blank. Step 4: press any key on the IBM XT keyboard. The display should show the data that is sent from the keyboard in hexadecimal format, while the Port B LEDs will display the da,ta in binary. Step 5: press the RESET or IRQ key to leave mode "D" and display the "M.A.L. Vers 4.XX" prompt again. Simple test programs Tables 1, 2 & 3 list some simple test programs for the MAL-4. Enter them using MODE-0 and run them using MODE-1. Table 3: Yes/No Decision Maker Address Data 0060 CD 12 05 0063 AE 10 0065 CD 11 CC 0068 AE 11 006A CD 11 FE 006D CD 13 2E 0070 4C 0071 3D D3 0073 27 F8 0075 A4 01 0077 26 07 0079 AE12 0078 CD 11 FE 007E 20 05 0080 AE13 - 0082 PCB and SCHEMATIC CAD r------·~----------- ·-·?t~ : / TV IF AMPLIFIE - / "I rl-f-t----H.lm,. 1!, ,._ . • ~ C-Uiiiflt• . ·-: j•4 : ..... ~ : CD 11 FE II mllll 1111111•111111111111111 11>1 1111111111 • 1.... '·""''"'lf•Nn,w 0085 A604 0087 CD 14 F3 008A 20D7 0100 54 68 65 20 41 6E 73 77 65 72 20 69 73 20 2D 3E 0110 50 72 65 73 73 20 61 20 48 65 79 20 4E 4F 57 21 • Design Single sided, Double sided and Multilayer boards 0120 2D 2D 2A 2A 20 20 59 45 53 21 20 20 2A 2A 2D 2D • Provides Surface Mount support 0130 2D2D28282020204E4F20202028282D2D • Standard output includes Dot Matrix/Laser/Inkjet printers, Pen Plotters, Photo-plotters and NC Drill Table 1 shows an input/output program. It simply takes the data on the input port (Port A) DIP SW1 and displays it on the output port (Port B) LEDs. Table 2 lists a tone generator program, which generates a variable tone from the external loudspeaker. This tone ranges in frequency from 20Hz to 5kHz and is set by the Port A DIP switch (SW1). Finally, Table 3 shows a program that generates a random YES/NO decision when you press any key on the keyboard. Monitor operation The monitor program, which is in the MC68HC705C8 EPROM, allows the user to access RAM, ROM and all the various registers within the single chip microcontroller. A detailed description of the operation of this monitor program follows. When power is applied or the RE- EASY-PC • Runs on PC/XT/AT/286/386 with Hercules, CGA, EGA or VGA. SET button is pressed, the display will show the prompt; ie, "M.A.L. Vers 4.XX. Enter Mode ... " This means that you may enter a mode of operation by pressing any of the keys indicated in Table 4. A detailed description of each mode follows: Mode "O" - Load, Examine or Modify Memory. Step 1: to enter this mode (Mode 0), press the "O" key when the "M.A.L. Vers 4.XX" prompt is displayed. The display will show "Ad.XXXX". The "Ad." is the ADDRESS prompt and indicates that the next four digits contain an address location. Step 2: enter desired address. If the microcontroller has just been reset, then the "XXXX" may contain anything. Conversely, if the microcontroller has not just been reset, the "XXXX" will contain the last address entered. The address displayed after the • Award winning EASY-PC is in use in over 12,000 installations in 70 Countries World-Wide • Superbly Easy to use • Not Copy Protected Options: • 1000 piece Schematic symbol library • Surface Mount symbol library • Gerber Import facility For full info 'phone, fax or write: BTC PO BOX432 GARBUTT 4814 QLD. PH (077) 21 5299 FAX (077) 21 5930 FEBRUARY 1993 49 Table 4: Monitor Operating Modes Key Mode Of Operation 0 Load, examine or modify memory 1 Run a program from a given location 2 Disassemble program ·froln a given location 3 No function 4 No function 5 No function 6 Keyboard beep on/off 7 MAL keyboard test 8 Test MAL display 9 No function A Print all RAM contents B No function C No function D Test IBM keyboard raw data E Test IBM keyboard characters F Shut down CPU & save RAM ENTER No function INC No function DEC No function "Ad." prompt will be the address that is to have data loaded, examined or modified. While the display shows "AdJOCXX", a 4-digit address may be entered via the keypad. The increment and decrement keys may be used to increment or decrement the 4-digit address by one. Step 3: press the ENTER key when the correct address is displayed. The display will now show "Ad.XXXX Data YY". The last two digits ("YY") contain the data that is in the address location displayed. Step 4: load, examine or modify the data using the keypad. Step 5: increment or decrement to the next address location (use the increment and decrement keys). Step 6: repeat steps 4 & 5 until you are finished. Step 7: press the ENTER key to leave mode "0". The display will show the "M.A.L. Vers 4.XX" prompt again. Note: when the data is displayed, the address location is constantly being interrogated and displayed at a rate of once every few milliseconds. Thus, if the data does not respond to key entries, then the address indicated is "read only". This also means that if the data changes, then the display will show the change almost instantly. This may be useful in monitoring an input port. MODE 1: Run a program from a given location. Step 1: to enter this mode, press the Where to buy the kit Parts for the MAL-4 Microcontroller Aid For Learning are available from E.S.D., PO Box 73, Glenbrook, NSW 2773. Phone (047) 39 4039. Prices are as follows: standard kit (incl. manual but does not incl. speaker or plugpack) - $249.00; standard kit with ZIF sockets plus toggle switches -$306; PC board only- $80; programmed MCU & manual - $48. Please add $10 for postage inside NSW, $15 for postage interstate. Payment should be made by cheque or money order. Note: copyright© of the PC board is retained by Electronic System Designs. 50 SILICON CHIP "1" key when the "M.A.L. Vers 4.XX" prompt is displayed. The display will show "Ad.XXXX Run". The "Ad." is the address prompt and indicates that the next four digits contain an address location. The "Run" prompt indicates that you are in the run mode. Step 2: enter the desired address. If the microcontroller has just been reset, then the "XXXX" may contain anything. If the microcontroller has not just been reset, then the "XXXX" will contain the last address entered. The address displayed after the "Ad." prompt is the address that the program will run from. While the display shows "Ad.XXXX", a 4-digit address may be entered via the keypad. The increment and decrement keys may be used to increment or decrement the 4-digit address by one. Step 3: when the correct address is displayed, press the ENTER key. The microcontroller will jump to the address that was in the display and run from there. The display will have "Ad.XXXX Run" on the first line and "Program Running" on the second line. Mode 2: Disassemble a program from a given location. Step 1: press the "2" key when the "M.A.L. Vers 4.XX" prompt is displayed . The display will show "Ad.XXXX" on the first line and "Disassemble from" on the second line. The "Ad." prompt indicates that the next four digits contain an address location. Step 2: enter the desired address via the keypad, or use the increment and decrement keys to increment or decrement the 4-digit address by one. The address displayed after the "Ad." prompt will be the address of the first instruction that is to be disassembled. Step 3: when the correct address is displayed, press the ENTER key. The display will show the address and a 1, 2 or 3 byte op-code on the first line and the mnemonic and operand on the second line. Step 4: increment to the next address. Step 5: repeat step 4 until you are finished. Step 6: press the enter key to leave mode "2 ". The display will show the "M.A.L. Vers 4.XX" prompt again. MODE F: Shut down CPU &save RAM. Step 1: press the "F" key from "M.A.L. Vers 4.XX" prompt. The dis- Table 5: MAL-4 Subroutines KALEX Reg.Use u. ACC& IX N Make port A an input None y Make port A an output None y IX y IX y LIGHT BOXES CLR LCD. Home cursor. RST AD. None y • Portuvee 4 • Portuvee 6 • Dual Level Home cursor line 1 RST AD.$00 None y TRIMMER e ldeal Description Name Address SETUP $1180 lnit. 1/0. lnit LCD. Set P.V. AINPUT $11BA AOUTPUT $11C3 LDISBUF1 $11CC LDISBUF2 $11FE CLRDISP $1205 HOME1 $120E Load 1st line of LCD with message pointed to by IX Load 2nd line of LCD with message pointed to by IX The UV People ETCH TANKS • Bubble Etch • Circulating HOME2 $1217 Home cursor line 2 RST AD.$40 None y WCTRL $1220 Write ACC to LCD control Reg. Ace y PCB DRILL WDATA $1240 Write ACC to LCD data Reg Ace y • Toyo HiSpeed RCTRL $1261 Read LCD control reg . to ACC Ace y MATERIALS RDATA $1275 Read LCD data reg. to ACC Ace y WAIT1 $1289 Fixed sous delay None y • PC Board: Riston, Dynachem e 3M Label/Panel Stock • Dynamark: Metal , Plastic DELAY1 $1295 100us times the ACC delay Ace y DELAYS $12A3 5ms times the ACC delay Ace y SCANKEY $112E Scans keypad, sets KEYV AL, KEYBIN & KEYASCII None y GETROW $1323 Used by SCANKEY subroutine Ace N CONVTOA $1317 Used by SCANKEY subroutine Ace N * AUSTRALIA'S N0.1 STOCKIST * I VISA I 40 Wallis Ave, East Ivanhoe 3079. Phone (03) 497 3422, Fax (03) 499 2381 LSNCON $13C6 LSN HEX to ASCII via ACC ACC y MSNCON $13D1 MSN HEX to ASCII via ACC ACC y Old Reprinted Electrical Books Beeps speaker 1kHz for 0.25s None y None ? IX y None y All N Ace y Build a 40,000 Volt Induction Coil ............ $9 Short Wave Radio Manual (1930) ........ $23 High Power Wireless Equipment (1911) $16 High Frequency Apparatus (1916) ........ $19 Build Short Wave Receivers (1932) ...... $13 Vision By Radio (1925) ......................... $16 1936 Radio Data Book .......................... $12 How to Become a Radio Amateur (1930) $6 All About Aerials ....................................... $5 Television (1938) ...................................... $5 Shortwave Coil Data Book (1937) ........... $5 . 1928 Radio Trouble-Shooting ............... $24 101 Short Wave Hook-Ups (1935) ........ $14 Vacuum Tubes in Wireless's ................. $21 Construction of Induction Coil ............... $21 Tesla: Man Out of Time (biography) ...... $22 Tesla Said, articles by Tesla 292pp ....... $74 My Inventions, by Nikola Tesla 111pp ... $27 Dr. Nikola Tesla - Complete Patents ..... $93 Tesla Coil Secrets ................................. $13 How to Build a Solar Cell That Works ...... $9 191 4 Catalog Electro Importing Co ....... $14 Electric Arc Furnaces ............................... $6 Experimental Television ........................ $25 BEEP $13DE DISPADD $13F9 Displays address in LCD DISPACC1 $1423 Displays ACC in LCD point.IX 0ISPACC $1420 Displays ACC in LCD fixed SETADD $1447 D10US $1498 D100US $14A1 Delay= ACC times 100us Ace y D1MS $1480 Delay = ACC times 1ms Ace y D10MS $1409 Delay = ACC times 1Oms Ace y 0100MS $14E6 Delay = ACC times 100ms Ace y D1SEC $14F3 Delay = ACC times 1s Ace y 01MIN $1500 Delay = ACC times 1 minute Ace y Displays address in LCD from keyboard Delay = ACC times 10us NB: ACC must be > $02 play will show "uP. in stop mode" on the first line and "SWITCH OFF NOW" on the second line. Step 2: switch off the power to the MAL-4 board. Step 3: check the battery warning LED (LED 2). This is used as an ammeter and indicates the relative power consumption of the MCU. When the MCU is in the stop mode, the LED will not light. If the LED is illuminated, repeat steps 1-3. Subroutines Finally, the MAL-4 has a number of subroutines that the programmer may find useful. Table 5 lists mos~ of these subroutines and their addresses. SC Allow 15 weeks for delivery of some items. Payment can be made by cheque made out to Plough Book Sales, PO Box 14, Belmont, Vic. 3216. Phone {052) 66 1262. F EB R UARY 1993 51