remote controller of air conditioner using msp430 user's ...p7.5/l5 1 p7.4/l4 2 p7.3/l3 3...

TI DesignsRemote Controller of Air Conditioner Using MSP430User's Guide

TI Designs Design FeaturesTI Designs provide the foundation that you need • Ultra Low Power with FRAM Technologyincluding methodology, testing and design files to • Infrared Code Sending with Optimized Timerquickly evaluate and customize the system. TI Designs

• Matrix Key Scan for 14 Buttonshelp you accelerate your time to market.• Segment LCD

Design ResourcesFeatured Applications

Design PageTIDU513 • Infrared LCD Remote ControllerMSP430FR4133 Product Folder

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1TIDU513–October 2014 Remote Controller of Air Conditioner Using MSP430 User's GuideSubmit Documentation Feedback

Copyright © 2014, Texas Instruments Incorporated

http://www.ti.com/too/TIDM-REMOTE-CONTROLLER-FOR-AC

http://www.ti.com/product/MSP430FR4133

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http://e2e.ti.com/support/development_tools/webench_design_center/default.aspx

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http://www.go-dsp.com/forms/techdoc/doc_feedback.htm?litnum=TIDU513

System Description www.ti.com

1 System DescriptionThis board demonstrates an ultra-low power, general purpose, infrared remote controller solution. Theboard uses a FRAM-based MCU MSP430FR4133, which supports features such as real time clock, buttonscan, infrared encoding, LED backlight, and LCD display.

1.1 MSP430FR4133The MSP430FR4133 is a FRAM-based ultra-low power mixed signal MCU. With the following features, theMSP430FR4133 is highly suitable for portable device applications.• 16-bit RISC architecture up to 16 Mhz• Wide supply voltage range from 1.8 V to 3.6 V• 64-Pin/56-Pin/48Pin TSSOP/LQFP package options• Integrated LCD driver with charge pump can support up to 4x36 or 8x32 segment LCD• Optimized 16-bit timer for infrared signal generation• Low power mode (LPM3.5) with RTC on:0.77 uA• Low power mode (LPM3.5) with LCD on: 0.936 uA• Active mode: 126 uA/MHz• 10^15 write cycle endurance low power ferroelectric RAM (FRAM) can be used to store data• 10-channel, 10-bit analog-to-digital converter (ADC) with built-in 1.5 V reference for battery powered

system• All I/Os are capacitive touch I/O

2 Remote Controller of Air Conditioner Using MSP430 User's Guide TIDU513–October 2014Submit Documentation Feedback


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www.ti.com Circuit Design

2 Circuit DesignThe highly-integrated mixed signal processer MSP430FR4133 has a small amount of componentsnecessary to realize a fully-functional air conditioner remote controller.

Refer to Figure 1 for the design block diagram.

Figure 1. Remote Controller Block Diagram

A 4x28 segment LCD is directly connected to the MSP430FR4133 LCD driver pins. Designers can swapthe COM and SEG pins to simplify the PCB layout.

A 4x4 matrix is used to detect 15 buttons. The matrix columns are connected to interrupt-enabled GPIOs(P1) to wake up the MSP430FR4133 from low power mode. MCU internal pull up/pull down resistors areused as button scan matrix pull up resistors. No external resistor is needed for button detection, and noexternal circuit is needed for battery voltage detection. The function is also realized by the MCU ADCmodule without any external component.



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Circuit Design www.ti.com

A 32.768 KHz watch crystal serves as the MCU FLL and RTC clock source. Two chip capacitors, C4 andC6, are used as the crystal loading capacitor. Designers must choose C4 and C6 values carefullyaccording to crystal specification. Cautious PCB layout design for the crystal is strongly recommended, tosecure system clock robustness. Figure 2 illustrates an example of the crystal PCB design.

Figure 2. Crystal PCB Layout

Refer to SLAA322B-MSP430 32-kHz Crystal Oscillators for detailed design considerations.



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http://www.ti.com/lit/an/slaa322b/slaa322b.pdf?keyMatch=MSP430%20crystal


www.ti.com Software Description

3 Software DescriptionThe software implements an interrupt-driven structure. In the main loop, the MCU stays in LPM3.5 mode.Interrupts from the button, RTC, and timer wake up the MCU for task processing. Inputs from the buttonare processed in task KeyProcess (), which handles system status and generates the content for the LCDdisplay and infrared signal. RTC generates a 3S interval interrupt to inform the system of battery voltagemeasurement.

Figure 3. Software Structure

3.1 Infrared Signal GenerationThere are several kinds of infrared modulation protocols in the industry. This design illustrates pulsedistance protocol with data frame format, the most commonly-used format for air conditioner remotecontrollers. As shown in Figure 4, each bit is composed of a carrier-modulated pulse and a space. Thespace’s width distinguishes logic 1 and logic 0 respectively. The carrier-modulated pulse width is constant.In this design, space length for 1 is 1690 uS, and 560 uS for digit 0. Modulated pulse width is 560 uS.

Figure 4. Pulse Distance Protocol, Bit Encoding



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Software Description www.ti.com

A complete data frame format is shown in Figure 5.

Figure 5. Pulse Distance Protocol, Data Frame Format

The envelope waveform depends on the frame format. Quantize all of the above items with a minimumtime slot of 0.56 ms, as shown in Table 1.

Table 1. Table 1. Pulse Distance Protocol, Data Encoding Quantization Table

Leading Code Logic ‘1’ Logic ‘0' Tail CodeCarrier Carrier Carrier CarrierItems

Modulated Space Modulated Space Modulated Space Modulated SpacePulse Pulse Pulse Pulse

Length 9 ms 4.5 ms 0.56 ms 1.69 ms 0.56 ms 0.56 ms 0.56 ms 0 msQuantizatio 16 8 1 3 1 1 1 0n

TA1 is used to generate an envelope waveform, and each pair of carrier-modulated pulse and space mustupdate the CCR0 and CCR2 once. The CCR0 depends on the carrier-modulated pulse period plus thespace period, while the CCR2 depends on the carrier-modulated pulse period. For instance, if TA1sources from SMCLK of 4 MHz and uses default divider configuration, CCR0 and CCR2 are individuallyconfigured as 54,000 and 36,000, to generate the leading code (9 ms carrier modulated pulse paired with4.5 ms space), and updated to 9,000 and 2,240 for logic 1 (see Figure 6). To send one full data frame,CCR0 and CCR2 must be updated 34 (1+8*2+8*2+1) times, which is achieved in the TA1 interruptroutine.

Figure 6. Pulse Distance Protocol, TA1 in Envelope Generation



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www.ti.com Test Setup and Results

To generate 38 kHz carrier with ¼ duty, CCR0 and CCR2 of TA0 are configured according to SMCLK. Forexample, with a 4 MHz SMCLK, CCR0 and CCR2 are individually configured to be 105 (4,000/38) and 26(4,000/38/4). Figure 7 shows how the duty setting works.

Figure 7. Pulse Distance Protocol, TA0 in Carrier Generation

4 Test Setup and Results

4.1 Power and Infrared Code Test2 AAA batteries power the board. By pressing the button pads with conductors, the user can observe thecontents on the LCD. Typical air-conditioner working modes and parameters can be configured. A micro-ampere meter is inserted in the power path to monitor the board power consumption as shown in Figure 8.Table 2 shows the sample board test results. To observe the infrared signal, use P1.0 with anoscilloscope. Figure 9 shows the infrared driving signal, typically 38 KHz PWM carriers, 30% duty.



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Test Setup and Results www.ti.com

Figure 8. Current Test Setup



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www.ti.com Test Setup and Results

Figure 9. Infra Transmitter Driving Signal from MCU

Table 2. Power Consumption Test Result (VCC = 3.0 V with RTC ON and LCD ON, LPM3.5)

Board NO# Vcc(V) Low Power Mode with RTC and LCD ON Standby Current (uA)1# 3.0 LPM3.5 2.62# 3.0 LPM3.5 3.43# 3.0 LPM3.5 3.64# 3.0 LPM3.5 2.8



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Test Setup and Results www.ti.com

4.2 Oscillation Frequency, Peak-Peak Voltage and Allowance TestThe ultra-low power 32.768 KHz crystal is the MCU RTC clock source and FLL reference clock source. Itis essential to secure the robustness from noises. According to SLAA322B-MSP430 32-kHz CrystalOscillators, the user can test the oscillation frequency and allowance to calculate the SF (Safety Factor),and evaluate system clock robustness. As described in SLAA322B, the SF should be greater than 3.

To perform the oscillation frequency test, download FR4133CrystalTest.c to the board. Then observe theMCLK frequency on P1.4, which indicates crystal oscillation frequency.

For an oscillation peak-peak voltage test, observe the signal on XOUT with a low capacitor (<2 pF) probe.For an oscillation allowance test, add a resistor (Rq) in series with the crystal, as shown in Figure 10.

Figure 10. Oscillation Allowance Test with Added Resister Rq

Table 3 shows the test results of sample boards with different value Rq.

Table 3. Oscillation Test with VCC = 3.0 V, Temperature = 25℃℃，，Crystal ESR = 35 KOhm

Rq = 0Ohm Rq=100KOhm Rq=200KOhmBoard SF

Freq.(Khz) Vp-p(mV) Freq.(Khz) Vp-p(mV) Freq.(Khz) Vp-p(mV)1# 32.769 512 32.770 616 32.770 560 >6.72# 32.769 504 32.770 624 32.770 568 >6.73# 32.770 448 32.770 536 32.771 488 >6.74# 32.769 488 32.770 560 32.770 520 >6.75# 32.770 512 32.770 600 32.771 584 >6.76# 32.769 472 32.770 568 32.771 528 >6.77# 32.770 630 32.768 608 32.769 520 >6.78# 32.767 480 32.770 576 32.770 536 >6.7

As shown in Table 3, even with a 200 KOhm resistor added in series with the crystal, the crystal worksnormally, which indicates the SF is greater than 6.7.



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http://www.ti.com/lit/pdf/SLAA322B


1

1

2

2

3

3

4

4

D D

C C

B B

A A

Title

Number RevisionSize

A

Date: 2014-9-11 Sheet ofFile: Z:\Share_Folder\..\RemoteControlerB.SchDocDrawn By:

XOUTXIN

DVCCGND

RSTTEST

L0L1L2L3L4L5 L8

L9L10L11L12L13L14L15L16L17L18L19L20L21L24L25L26L27

C16101GND

KEYOUT4KEYOUT3KEYOUT2KEYOUT1

KEYSHIFT

BACKLI GHTKEYIN1

KEYIN2KEYIN3KEYIN4

P7.5/L51

P7.4/L42

P7.3/L33

P7.2/L24

P7.1/L15

P7.0/L06

P4.7/R137

P4.6/R238

P4.5/R339

P4.4/LCDC210

P4.3/LCDC111

P4.2/XOUT12

P4.1/XIN13

DVSS14

DVCC15

RST/NMI/SBWTDIO16

TEST/SBWTCK17

P4.0/TA1.118

P8.3/TA1.219

P8.2/TA1CLK20

P1.7/TA0.1/TDO/A721

P1.6/TA0.2/TDI/TCLK/A622

P1.5/TA0CLK/TMS/A523

P1.4/MCLK/TCK/A424

P1.3/UCA0STE/A325

P1.2/UCA0CLK/A226

P1.1/UCA0RXD/UCA0SOMI/A1/Veref+27

P1.0/UCA0TXD/UCA0SIMO/A0/Veref–28

P5.5/L3729

P5.4/L3630

P5.3/UCB0SOMI/UCB0SCL/L3531

P5.2/UCB0SIMO/UCB0SDA/L3432

P5.1/UCB0CLK/L3333

P5.0/UCB0STE/L3234

P2.7/L3135

P2.6/L3036

P2.5/L2937

P2.4/L2838

P2.3/L2739

P2.2/L2640

P2.1/L2541

P2.0/L2442

P6.5/L2143

P6.4/L2044

P6.3/L1945

P6.2/L1846

P6.1/L1747

P6.0/L1648

P3.7/L1549

P3.6/L1450

P3.5/L1351

P3.4/L1252

P3.3/L1153

P3.2/L1054

P3.1/L955

P3.0/L856

U1

MSP430FR4133

SEND

32768

C6

200

C4

200

GND

1234

P1

JTAG-SBW

C9105

RSTTEST

DVCC

104

C1

104

C2

104

C3

104C5

GND

1M

R1

0RR2

47KR3

GND

C8

106

C7

104

GND2KR4

L28L29L30L31

GND

VCC

C14

106

C15

104

C10

104

C11

104 100uF

C13

3V

+1

|2

U2

Battery

4.7uF

C12

DVCC

GND

KEYSHIFT

1 2

SHIFT

Button-2p

1 2FAN

Button-2p

1 2MODE

Button-2p

1 2ON/OFF

Button-2p

1 2LIGHT

Button-2p

1 2+

Button-2p

1 2TURBO

Button-2p

1 2SAVE

Button-2p

1 2-

Button-2p

1 2SILENT

Button-2p

1 2

HEAT/HEALTH.AIR

Button-2p

1 2

TEMP.DIS

Button-2p

1 2

COLD/BLOW.HEAT

Button-2p

1 2

TIMER/SWINGUD

Button-2p

1 2

SLEEP/SWINGLR

Button-2p

KEYIN4 KEYIN3 KEYIN2 KEYIN1

KEYOUT1

KEYOUT2

KEYOUT3

KEYOUT4

L0L1L2L3L4L5

L28L29

L8L9L10L11L12L13L14L15

L16L17L18L19L20L21L24L25L26L27

123456789

101112131415

16171819202122232425262728

J1

Header14*2

Q2

VCC

SEND

GND

Q1

GND

VCC

BACKLI GHT

0R

R5

0R

R6

220RR9

100KR11

2R2

R7

300R

R8

10R

R10

L30L31

LED1Infrared Radiation

LED2Backlight

none

COM1COM2COM3COM4

www.ti.com Design Files

5 Design Files

5.1 SchematicsTo download the schematic, see the design files at http://www.ti.com/tool/TIDU513

Figure 11. Schematic



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Design Files www.ti.com

5.2 Bill of MaterialsTo download the bill of materials (BOM), see the design files at http://www.ti.com/tool/TIDU513.

Table 4. BOMDesignator Description Quantity

+, -, COLD/BLOW.HEAT, FAN, HEAT/HEALTH.AIR, Buttons 14LIGHT, MODE, ON/OFF, SAVE, SILENT,SLEEP/SWINGLR, TEMP.DIS, TIMER/SWINGUD,TURBO

C1, C2, C3, C5 0805, Chip Capacitor, X7R,16 V, +-10% 4

C4, C6 0805, Chip Capacitor Chip Capacitor 200 X7R,16 V, +- 210%

C7, C10, C11, C14 0805, Chip Capacitor 104 X7R, 16 V, +-10% 4

C8, C16 0805, Chip Capacitor 106 X7R,16 V, +-10% 1

C9 0805, Chip Capacitor 105 X7R,16 V, +-10% 1

C12 0805, Chip Capacitor Cap Pol1 X7R,16 V, +-10% 1

C13 0805, Chip Capacitor Cap Pol1 X7R,16 V, +-10% 1

C15 0805, Chip Capacitor 102 X7R,16 V, +-10% 1

Crystal 32.768 Khz crystal 1

J1 Header14*2 1

LED1 Infrared Radiation transmitter 1

LED2 Backlight LED 1

P1 JTAG-SBW 1

Q1, Q2 Transistor 2

R1, R2, R3, R4, R5, R6, R8, R9, R10, R11 0805 Chip Resistor 10

R7 0805 Chip Resistor 1

SHIFT Button 1

U1 MSP430F4133 1

U2 Battery 1



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5.3 PCB LayoutTo download the layer plots, see the design files at http://www.ti.com/tool/TIDU513.



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Figure 12. PCB Layer 1



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Figure 13. PCB Layer 2



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5.4 Gerber FilesTo download the Gerber files, see the design files at http://www.ti.com/tool/TIDU513.

6 Software FilesTo download the software files, see the design files at http://www.ti.com/tool/TIDU513



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www.ti.com About the Author

7 About the AuthorJASON GUO is a system application engineer at Texas Instruments, where he is responsible fordeveloping reference design solutions for the industrial segment. Jason earned his Engineering Master ofIntegrated Circuits Design from Peking University, and Bachelor of Electronic Engineering from ShanghaiJiaotong University.



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remote controller of air conditioner using msp430 user's ...p7.5/l5 1 p7.4/l4 2 p7.3/l3 3...

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