The Microcontroller Idea Book - Jan Axelson's Lakeview Research

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Chapter 3 Figure 3-6. BASIC-52’s sign-on message and a simple program, using the Windows Terminal accessory for communications. Procomm Plus for DOS and Microsoft Windows 3.1’s Terminal Accessory, but other communications software should have similar features and abilities. Turn on the host computer and run your communications software. Configure the software for 8 data bits, no parity, and 1 stop bit. The baud rate you select isn’t critical, since BASIC-52 automatically adjusts to what you are using. To start, use a rate of 9600 or less. Don’t enable any handshaking or flow-control options such as XON/XOFF or RTS/CTS. Select the appropriate serial, or COM, port, if necessary. If you’re using an MS-DOS (IBM-compatible) computer, you must find a COM port and interrupt-request (IRQ) level that aren’t being used by your modem, mouse, or another device. Because COM1 and COM3 often share an IRQ level, as do COM2 and COM4, you generally can’t use COM1 and COM3 at the same time, or COM2 and COM4. If you have an external modem, you can unplug it and use its serial port. In Procomm Plus, use the line/port setup menu (ALT+P) to configure. In the Windows Terminal, use the Settings menu. Cable together the serial ports of the host and target systems. 36 The Microcontroller Idea Book
You’re now ready to power up the target system. Turn on its power supply, and press the SPACE bar at the host’s keyboard. You should see this BASIC-52 sign-on message and prompt: *MCS-51(tm) BASIC V1.1* READY Figure 3-6 shows the sign-on message and a simple program, using Windows’ Terminal accessory for communications. Troubleshooting If you don’t see the prompt, it’s time to troubleshoot. Getting the system to boot up the first time can be the most challenging part of a project, especially when serial communications are involved. Here are some things that may help you isolate the cause of the problem: • Try again by pressing and releasing S1 and pressing the space bar. If you are using a 32K RAM for U7, BASIC-52 requires about 1 second to perform its memory check after a reset, before it will respond to the space bar. With an 8K RAM, the delay is a few tenths of a second (proportionately longer with slower crystals). • Double-check the easy things. Are the communications parameters correct? Did you select the correct serial port? Are all ICs inserted? • Verify that pin 9 of U2 goes high, then low, when you press and release S1. • Check the power and ground pins of all ICs for proper voltages. • Connect a logic probe to pin 10 of U2. When you press the space bar, you should see the logic level toggle as U2 receives the ASCII code for a space (20h). If not, you probably have a problem in the setup of your communications software or in the serial cabling. • Verify that pin 30 of U2 is toggling (at 1/6 the crystal frequency, if you have an oscilloscope to measure). This indicates that the oscillator circuit is functioning. • Verify that pins 21-28 and 32-39 of U2 toggle as BASIC-52 performs its memory check immediately after powering up or rebooting. Powering Up • If all else fails, recheck your wiring for missing or misrouted wires. Sometimes there’s no alternative but to go through the schematic connection by connection, checking each with an ohmmeter. The Microcontroller Idea Book 37
Page 1 and 2: The Microcontroller Idea Book Circu
Page 3 and 4: Table of Contents Chapter 1 Microco
Page 5 and 6: Chapter 11 Control Circuits 185 Swi
Page 7 and 8: Introduction Introduction This book
Page 9 and 10: A chapter on assembly-language inte
Page 11 and 12: Microcontroller Basics 1 Microcontr
Page 13 and 14: But along with cheap, powerful, and
Page 15 and 16: makes sense. For simpler designs, a
Page 17 and 18: Microcontroller Basics Several tech
Page 19 and 20: Interpreters and compilers are two
Page 21 and 22: Inside the 8052-BASIC 2 Inside the
Page 23 and 24: Inside the 8052-BASIC • You can a
Page 25 and 26: hardware manuals. For programming,
Page 27 and 28: Inside the 8052-BASIC Figure 2-2 Pi
Page 29 and 30: Inside the 8052-BASIC Table 2-2. (p
Page 31 and 32: Inside the 8052-BASIC Code and data
Page 33 and 34: Powering Up 3 Powering Up This chap
Page 35 and 36: Powering Up Table 3-1. Parts list f
Page 37 and 38: Powering Up Figure 3-2. Truth table
Page 39 and 40: Powering Up Jumper J3 chooses the c
Page 41 and 42: Powering Up Figure 3-3. This is the
Page 43 and 44: Powering Up Construction Tips These
Page 45: Powering Up Serial Connectors Conne
Page 49 and 50: Powering Up PRINT XTAL Line Editing
Page 51 and 52: Powering Up PORT 1 Bit Values: Bit
Page 53 and 54: Powering Up Listing 3-3. Allows use
Page 55 and 56: 10 CLOCK 1:TIME=0:SEC=0 20 A=0 30 P
Page 57 and 58: Saving Programs 4 Saving Programs I
Page 59 and 60: guaranteed for at least ten years.
Page 61 and 62: Saving Programs Figure 4-3. Circuit
Page 63 and 64: Jumper J4 is optional. It enables y
Page 65 and 66: memory on bootup. This is what allo
Page 67 and 68: This is the recommended algorithm f
Page 69 and 70: Saving Programs Figure 4-5. Additio
Page 71 and 72: problems with EPROMs that have a 10
Page 73 and 74: supply. The chip requires an additi
Page 75 and 76: Programming 5 Programming When you
Page 77 and 78: Subroutines have two advantages. Fi
Page 79 and 80: Programming • Hexadecimal numbers
Page 81 and 82: Programming It can be hard to find
Page 83 and 84: Programming Math Operators = + - *
Page 85 and 86: Programming expression / expression
Page 87 and 88: Programming DO: [program statements
Page 89 and 90: Programming LOG(expression) Returns
Page 91 and 92: Programming PH0.@ Same as PRINT@, b
Page 93 and 94: Programming RCAP2 Retrieves or assi
Page 95 and 96: Programming PRINT TAB(2) “hello
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Inputs and Outputs 6 Inputs and Out
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Unassigned space remains in the mem
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U11 is a 74HCT138 3-to-8-line decod
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If you wish, you can wire U14’s i
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Inputs and Outputs Figure 6-4. Outp
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Inputs and Outputs Listing 6-2. Set
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The 82C55 also has CMOS-compatible
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Inputs and Outputs Pin Symbol Input
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Inputs and Outputs An 8255 Interfac
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Inputs and Outputs XBY(0FC03h)=9BH
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To set or clear a different bit, de
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Switches and Keypads 7 Switches and
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Switches and Keypads Figure 7-2. Us
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exact value depending on the switch
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Switches and Keypads Figure 7-4. Tw
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Switches and Keypads Figure 7-6. A
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Switches and Keypads Custom Keypads
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Switches and Keypads • A single c
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Switches and Keypads Listing 7-3. T
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Displays 8 Displays In addition to
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Displays Figure 8-1. LED interfaces
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Displays Figure 8-2. Ways to connec
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Displays Figure 8-4. Four output po
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Displays Figure 8-5. The ICM7218D c
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In Figure 8-5’s circuit, an 82(C)
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Displays Figure 8-7. With the TC721
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Displays Figure 8-8. With a charact
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Table 8-1. LCD modules containing t
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Each character in the CG ROM and CG
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Displays Interfacing Full control o
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Displays Listing 8-4 (page 2 0f 2).
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Displays Listing 8-5. Displays key
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Displays Listing 8-6 (page 2 of 2).
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Using Sensors to Detect and Measure
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• What power supplies are availab
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Page 169 and 170:
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different ground symbols for the tw
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10 REM use single-ended mode 20 REM
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Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Clocks and Calendars 10 Clocks and
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Listing 10-1. Uses BASIC-52’s rea
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Clocks and Calendars Figure 10-1. P
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Clocks and Calendars Table 10-1. Re
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If you want an alarm frequency othe
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Clocks and Calendars Listing 10-3 (
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Clocks and Calendars Listing 10-3 (
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Control Circuits 11 Control Circuit
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the LSTTL part, and wire the desire
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Control Circuits Listing 11-1. Cont
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Control Circuits Listing 11-2. Demo
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Control Circuits disables the outpu
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Page 207 and 208:
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Wireless Links 12 Wireless Links Wi
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Wireless Links Figure 12-2. This in
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Wireless Links Because there are th
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Wireless Links Figure 12-4. The GP1
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through the LEDs. If you prefer an
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Wireless Links Figure 12-6. Using a
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Wireless Links Figure 12-7. Using a
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Wireless Links IREDs emit energy at
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In the infrared link, the amount of
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Calling Assembly-language Routines
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into memory in the 8052-BASIC syste
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2048h in code memory. This is becau
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Binary value 1100 0101 Hex equivale
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Successful assembly is a good sign,
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statement must match the address in
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Page 241 and 242:
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• BASIC-52’s ON EX1 instruction
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Page 247 and 248:
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Running BASIC-52 from External Memo
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14-1 for longer delays between writ
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In Figure 3-1, tie pin 31 of U2 (EA
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Related Products 15 Related Product
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Finally, a compiled BASIC program u
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Related Products Figure 15-3. Blue
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Sources Appendix A Sources This App
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Programming and Interfacing the 805
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Sources Product Vendors The followi
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Sources Electronics 123 17921 Rowla
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Sources Micro Future 40944 Cascado
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Sources Siemens Components 2191 Lau
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Programs for Loading Files Appendix
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Programs for Loading Files Listing
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Number Systems Appendix C Number Sy
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Number Systems This table shows the
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Index Index A ADC, 158 - 169 addres
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Index S sample and hold, 169 SBC, 3
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The Microcontroller Idea Book - Jan Axelson's Lakeview Research

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