1.3) 設(shè)置
下載并解壓縮應(yīng)用筆記文件 (ZIP, 2.4MB)。

根據(jù)圖1來(lái)組裝硬件。

按照表1連接MAX1234評(píng)估板連接器J1和MINIQUSB-X+擴(kuò)展電路板(包含在MINIQUSB+中)?？梢圆捎?M?內(nèi)部連接器922576-40來(lái)替代連接MAX1234評(píng)估板的焊線，將其插入到J1中，以提供方便的連接點(diǎn)。不要連接終端模塊TB1。

表1. MAX1234評(píng)估板和MINIQUSB+電路板之間的連接設(shè)置 MAX1234 Signal MAX1234 EV Kit MINIQUSB-X+ MINIQUSB Signal
GND J1-1 H2-8 GND
VCC J1-7 H2-1 3.3V supply from MINIQUSB+
BUSY-Bar J1-27 H2-7 GPIO-K7 (MAXQ2000-INT2)
PENIRQ-Bar J1-29 H1-3 GPIO-K6 (MAXQ2000-INT1)
KEYIRQ-Bar J1-31 H1-8 GPIO-K5 (MAXQ2000-INT0)
DOUT J1-35* H2-2 MISO (SPI master in, slave out)
DIN J1-36* H2-5 MOSI (SPI master out, slave in)
SCLK J1-37* H2-3 SCLK (SPI clock)
CS-Bar J1-38 H2-4 CS-bar (SPI chip select)
USB+5V J1-5 J4-7 USB+5V supply from PC
* 注釋：必須通過連接器J1來(lái)驅(qū)動(dòng)MAX1234評(píng)估板數(shù)字輸入，不能直接將其驅(qū)動(dòng)至U1周圍的測(cè)試點(diǎn)。必須采用板上MAX1841電平轉(zhuǎn)換器來(lái)驅(qū)動(dòng)MAX1234評(píng)估板數(shù)字信號(hào)。

將MINIQUSB+插入到擴(kuò)展板的頂部。
連接MINIQUSB+和PC的USB端口。如果這是MINIQUSB+第一次和PC連接，將出現(xiàn)即插即用向?qū)?。指南窗口將提示器件?qū)動(dòng)器(它包含在隨附zip文件中)的安裝位置。
啟動(dòng)固件更新批處理文件FWUPDATE.BAT來(lái)更新MINIQUSB+固件。
固件更新完成后，從PC的USB端口斷開MINIQUSB+。

圖1. 硬件配置(在后面章節(jié)中連接觸摸屏)。

圖2. 系統(tǒng)圖片，使用一個(gè)3M內(nèi)部連接器來(lái)連接MINIQUSB+和MAX1234評(píng)估板。

1.4) 步驟
將MAX1234評(píng)估板跳接器JU1設(shè)置到“MAX1234”位置。
將MINIQUSB+連接至PC的USB端口。確定DACOUT電壓 = mid-scale (2.2V)。
啟動(dòng)DEMO1234.EXE程序。屏幕上將出現(xiàn)控制臺(tái)。
在控制臺(tái)中輸入下面的" title="面的">面的命令序列。
表2. 連接并驗(yàn)證命令序列 DEMO1234 Command*
Expected Program Output SPI data in
?Verification**
C
?Board connected.

Got board banner: Maxim MINIQUSB V01.05.41 >
? Firmware version is OK.
?(configured for SPI auto-CS 4-byte mode) (SCLK=2MHz) ...

??
T W DD FF
?Write_Register(regAddr=0x000b wr_DAC_data??????? ,
?data=0x00ff
??????? {(no bits defined for this register)}) result = 1

?0x000b 0x00ff DACOUT = full-scale (4.5V)
T R DD
?Read_Register(regAddr=0x800b wr_DAC_data???????? ) result = 1,
?buffer = 0x00ff = 255
??????? {(no bits defined for this register)}

?0x800b 0x0000 Data buffer = 0x00ff
T W DD 80
????
Write_Register(regAddr=0x000b wr_DAC_data??????? ,
?data=0x0080
??????? {(no bits defined for this register)}) result = 1

?0x000b 0x0080 DACOUT = mid-scale (2.2V)
T R DD
?Read_Register(regAddr=0x800b wr_DAC_data???????? ) result = 1,
?buffer = 0x0080 = 128
??????? {(no bits defined for this register)}

?0x800b 0x0000 data buffer = 0x0080
* DEMO1234 Command命令列出了輸入到DEMO1234.exe程序中的命令。
** Verification列出了可以進(jìn)行的物理測(cè)試，驗(yàn)證所執(zhí)行的命令。

1.5) SPI data in實(shí)例格式
SPI data in一列列出了驅(qū)動(dòng)至MAX1233/MAX1234 DIN引腳的SPI數(shù)據(jù)，采用了十六進(jìn)制格式，最高有效字節(jié)在前。例如，序列0x000b 0x00ff中的SPI數(shù)據(jù)表示同步輸入到DIN的32位序列是0000 0000 0000 1011 0000 0000 1111 1111。第一位0用于寄存器寫操作，1用于寄存器讀操作。

寄存器寫操作是0000 0000 a7-a0 d15-d0格式的32位SPI傳送過程。
寄存器讀操作是1000 0000 a7-a0 0000 0000格式的32位SPI傳送過程，在最后16位，接收到的數(shù)據(jù)從DOUT同步輸入。

2) 模擬I/O實(shí)例
下面的例子介紹了怎樣使用DEMO1234.EXE程序來(lái)控制DAC輸出，配置基準(zhǔn)電壓，測(cè)量AUX1/AUX2/BAT1/BAT2電壓輸入，以及測(cè)量?jī)?nèi)部MAX1234溫度。

2.1) 控制DAC輸出電壓
由兩個(gè)寄存器來(lái)控制DAC。寫入DAC數(shù)據(jù)寄存器來(lái)設(shè)置輸出電壓。寫入DAC控制寄存器來(lái)關(guān)斷或者對(duì)DAC上電。默認(rèn)上電狀態(tài)是DAC加電，DAC輸出位于量程中部。DAC滿量程電壓通常為AVDD的90% (最小85%，最大95%)。

對(duì)于AVDD = 3.3V ±5%，DACOUT滿量程范圍在2.65V和3.27V之間，通常為2.96V。
對(duì)于AVDD = 5.0V ±5%，DACOUT滿量程范圍在4.02V和4.97V之間，通常為4.48V。

表3. DAC輸出命令 DEMO1234 Command
?Action SPI data in
?MAX1233 (3.3V) MAX1234 (5.0V)
T W DD FF
?DACOUT = full-scale 0x000b 0x00ff
?DACOUT = 2.96V DACOUT = 4.48V
T W DD 00
?DACOUT = 0V 0x000b 0x0000
?DACOUT = 0.0V DACOUT = 0.0V
T W DD 80
?DACOUT = mid-scale 0x000b 0x0080
?DACOUT = 1.485V DACOUT = 2.25V
T W DC 8000
?Disable DAC 0x0042 0x8000
?DACOUT = 0.0V DACOUT = 0.0V
T W DC 0
?Enable DAC 0x0042 0x0000
?DACOUT = 1.485V DACOUT = 2.25V

2.2) 選擇ADC基準(zhǔn)電源模式
ADC需要一個(gè)基準(zhǔn)電壓。對(duì)于典型的嵌入式系統(tǒng)工作，默認(rèn)設(shè)置是fine。在自動(dòng)上電模式(ADC3210 = 0000，RES10 = 00)下，MAX1233/MAX1234提供自己的內(nèi)部基準(zhǔn)電壓。在每次測(cè)量之前，內(nèi)部基準(zhǔn)自動(dòng)上電，測(cè)量完成后關(guān)斷。

對(duì)于第一次診斷，保持上電模式(ADC3210 = 0000，RES10 = 01)支持使用手持式DVM對(duì)基準(zhǔn)電壓進(jìn)行外部驗(yàn)證。

ADC掃描選擇位設(shè)置為0000，寫入ADC控制寄存器(0x40)，來(lái)設(shè)置ADC基準(zhǔn)電源模式。RES1/RES0位選擇基準(zhǔn)電源模式，基準(zhǔn)控制位RFV選擇內(nèi)部1.0V或者2.5V基準(zhǔn)(請(qǐng)參考MAX1233/MAX1234數(shù)據(jù)資料的表13)。

ADC控制字：x x 0 0 0 0 RES1 RES0 x x x x x x x RFV

表4. 內(nèi)部基準(zhǔn)命令 DEMO1234 Command
?Action SPI data in
?Verification
T W AC 0100
?Internal 1V reference always powered; write ADC control word with
ADC3210 = 0000,
RES10 = 01,
RFV = 0 0x0040 0x0100
?Voltage at pin 12 REF is between 0.98V and 1.02V
T W AC 0101
?Internal 2.5V reference always powered; write ADC control word with
ADC3210 = 0000,
RES10 = 01,
RFV = 1 0x0040 0x0101
?Voltage at pin 12 REF is between 2.47V and 2.53V
T W AC 0001
?Internal 2.5V reference powered when needed; write ADC control word with
ADC3210 = 0000,
RES10 = 00,
RFV = 1 0x0040 0x0001
?Voltage at pin 12 REF will be powered only briefly as necessary

表5. 外部基準(zhǔn)命令 DEMO1234 Command
?Action SPI data in
?
T W AC 0300
?External reference must be provided;
ADC_control_wr_demand_scan:(write)demand scan
ADC_control_AD0000:configure reference
ADC_control_RES11:external reference 0x0040 0x0300
?

2.3) 測(cè)量外部電壓輸入AUX1和AUX2
表6. ADC測(cè)量命令序列 DEMO1234 Command
?Action (Triggered by A/D3210 Bits) SPI data in
?
T M8
?Measure AUX1 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x2301

0x8007 0x0000
?
T W AC 2301
?Trigger ADC scan of AUX1;
ADC control word 0x2301 means:
ADC_control_wr_demand_scan
ADC_control_AD1000 /* measure AUX1 */
ADC_control_RES11 /* 12-bit resolution */
ADC_control_AVG00 /* no averaging */
ADC_control_CNR00 /* conversion rate 3.5μs */
ADC_control_RFV /* RFV=1: VREF=2.5V */ 0x0040 0x2301
?
T R A1
?Read AUX1 result AUX1_code 0x8007 0x0000
?
T M9
?Measure AUX2 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x2701

0x8008 0x0000
?

2.4) 將AUX1和AUX2轉(zhuǎn)換結(jié)果譯為物理值
下面的C/C++偽代碼片斷總結(jié)了DEMO1234程序是怎樣解釋AUX1和AUX2轉(zhuǎn)換結(jié)果的。

??? /* ADC control resolution value selects num_codes 4096 (12-bit), 1024 (10-bit), or 256 (8-bit) */
??? int num_codes = 4096; /* ADC_control_RES11: 12-bit resolution */

??? /* Voltage that corresponds to the full-scale ADC code; may be internal 1V or 2.5V ref, or ext ref. */
??? double ADC_fullscale_voltage = 2.5; /* ADC_control_RFV=1: VREF=2.5V.? RFV=0: VREF=1.0V. */

??? /* AUX1_code is the 16-bit result read by SPI command 0x8007 */
??? double AUX1_Voltage = (AUX1_code * ADC_fullscale_voltage) / num_codes;
???
??? /* AUX2_code is the 16-bit result read by SPI command 0x8008 */
??? double AUX2_Voltage = (AUX2_code * ADC_fullscale_voltage) / num_codes;

2.5) 測(cè)量外部電壓輸入BAT1和BAT2
表7. ADC測(cè)量命令序列 DEMO1234 Command
?Action (Triggered by A/D3210 Bits) SPI data in
?
T M6
?Measure BAT1 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x1b01

0x8005 0x0000
?
T W AC 1b01
?Trigger ADC scan of BAT1;
ADC control word 0x1b01 means:
ADC_control_wr_demand_scan
ADC_control_AD0110 /* measure BAT1 */
ADC_control_RES11 /* 12-bit resolution */
ADC_control_AVG00 /* no averaging */
ADC_control_CNR00 /* conversion rate 3.5μs */
ADC_control_RFV /* RFV=1: VREF=2.5V */ 0x0040 0x1b01
?
T R B1
?Read BAT1 result BAT1_code 0x8005 0x0000
?
T W AC 1b21
?Trigger ADC scan of BAT1;
ADC control word 0x1b21 means:
ADC_control_wr_demand_scan
ADC_control_AD0110 /* measure BAT1 */
ADC_control_RES11 /* 12-bit resolution */
ADC_control_AVG00 /* no averaging */
ADC_control_CNR10 /* conversion rate 10μs */
ADC_control_RFV /* RFV=1: VREF=2.5V */ 0x0040 0x1b21
?
T R B1
?Read BAT1 result BAT1_code 0x8005 0x0000
?
T M7
?Measure BAT2 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x1f01

0x8006 0x0000
?

2.6) 將BAT1和BAT2轉(zhuǎn)換結(jié)果譯為物理值
下面的C/C++偽代碼片斷總結(jié)了DEMO1234程序是怎樣解釋BAT1和BAT2轉(zhuǎn)換結(jié)果的。注意：通過一個(gè)4:1輸入分配器來(lái)測(cè)量BAT1和BAT2。
??? /* ADC control resolution value selects num_codes 4096 (12-bit), 1024 (10-bit), or 256 (8-bit) */
??? int num_codes = 4096; /* ADC_control_RES11: 12-bit resolution */

??? /* Voltage that corresponds to the full-scale ADC code; may be internal 1V or 2.5V ref, or ext ref. */
??? double ADC_fullscale_voltage = 2.5; /* ADC_control_RFV=1: VREF=2.5V.? RFV=0: VREF=1.0V. */

??? /* Note: BAT1 and BAT2 measure through a 4:1 input divider. */

??? /* BAT1_code is the 16-bit result read by SPI command 0x8005 */
??? double BAT1_Voltage = 4 * (BAT1_code * ADC_fullscale_voltage) / num_codes;

??? /* BAT2_code is the 16-bit result read by SPI command 0x8006 */
??? double BAT2_Voltage = 4 * (BAT2_code * ADC_fullscale_voltage) / num_codes;

2.7) 測(cè)量?jī)?nèi)部溫度TEMP1和TEMP2
表8. ADC測(cè)量命令序列 DEMO1234 Command
?Action (Triggered by A/D3210 Bits) SPI data in
?
T MA
?Measure TEMP1 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x2b01

0x8009 0x0000
?
T W AC 2b01
?Trigger ADC scan of TEMP1;
ADC control word 0x2b01 means:
ADC_control_wr_demand_scan
ADC_control_ AD1010 /* measure TEMP1 */
ADC_control_RES11 /* 12-bit resolution */
ADC_control_AVG00 /* no averaging */
ADC_control_CNR00 /* conversion rate 3.5μs */
ADC_control_RFV /* RFV=1: VREF=2.5V */ 0x0040 0x2b01
?
T R T1
?Read TEMP1 result TEMP1 _code 0x8009 0x0000
?
T MC
?Measure TEMP1, TEMP2 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x3301

0x8009 0x0000

0x800a 0x0000
?
T W AC 3301
?Trigger ADC scan of TEMP1 and TEMP2;
ADC control word 0x3301 means:
ADC_control_wr_demand_scan
ADC_control_ AD1100 /* measure TEMP1,TEMP2 */
ADC_control_RES11 /* 12-bit resolution */
ADC_control_AVG00 /* no averaging */
ADC_control_CNR00 /* conversion rate 3.5μs */
ADC_control_RFV /* RFV=1: VREF=2.5V */ 0x0040 0x3301
?
T R T1
?Read TEMP1 result TEMP1 _code 0x8009 0x0000
?
T R T2
?Read TEMP2 result TEMP2 _code 0x800a 0x0000
?

2.8) 將TEMP1轉(zhuǎn)換結(jié)果譯為物理值
下面的C/C++偽代碼片斷總結(jié)了DEMO1234程序是怎樣解釋TEMP1轉(zhuǎn)換結(jié)果的。
??? /* ADC control resolution value selects num_codes 4096 (12-bit), 1024 (10-bit), or 256 (8-bit) */
??? int num_codes = 4096; /* ADC_control_RES11: 12-bit resolution */

??? /* Voltage that corresponds to the full-scale ADC code; may be internal 1V or 2.5V ref, or ext ref. */
??? double ADC_fullscale_voltage = 2.5; /* ADC_control_RFV=1: VREF=2.5V.? RFV=0: VREF=1.0V. */

??? /* TEMP1_code is the 16-bit result read by SPI command 0x8009 */
??? double TEMP1_Voltage = (TEMP1_code * ADC_fullscale_voltage) / num_codes;
???
??? /* Calibration values */
??? const double Temp1V_Room = 0.590; // temp1 voltage at room temperature 25C
??? const double Temp1K_Room = 298.15;? // Room temperature Kelvins (298.15K=25C)
??? const double Temp1V_Per_K = -0.002; // TempCo -2mV per degree C
???
??? /* Convert to absolute temperature */
??? double Kelvin = (TEMP1_Voltage - Temp1V_Room) / Temp1V_Per_K + Temp1K_Room;
???
??? /* Optional conversion to commonly used temperature units */
??? double Centigrade = Kelvin - 273.15;
??? double Fahrenheit = (Centigrade * 9.0 / 5.0) + 32;

2.9) 將TEMP1和TEMP2轉(zhuǎn)換結(jié)果譯為物理值
下面的C/C++偽代碼片斷總結(jié)了DEMO1234程序是怎樣解釋TEMP1和TEMP2轉(zhuǎn)換結(jié)果的。TEMP2只在和TEMP1對(duì)比時(shí)才有意義。
??? /* ADC control resolution value selects num_codes 4096 (12-bit), 1024 (10-bit), or 256 (8-bit) */
??? int num_codes = 4096; /* ADC_control_RES11: 12-bit resolution */

??? /* Voltage that corresponds to the full-scale ADC code; may be internal 1V or 2.5V ref, or ext ref. */
??? double ADC_fullscale_voltage = 2.5; /* ADC_control_RFV=1: VREF=2.5V.? RFV=0: VREF=1.0V. */

??? /* TEMP1_code is the 16-bit result read by SPI command 0x8009 */
??? double TEMP1_Voltage = (TEMP1_code * ADC_fullscale_voltage) / num_codes;
???
??? /* TEMP2_code is the 16-bit result read by SPI command 0x800a */
??? double TEMP2_Voltage = (TEMP2_code * ADC_fullscale_voltage) / num_codes;
???
??? /* Calibration values */
??? const double K_Per_Temp21_Delta_V = 2680.0; // nominal 2680 5/27/2002
???
??? /* Convert to absolute temperature */
??? double Kelvin = (TEMP2_Voltage - TEMP1_Voltage) * K_Per_Temp21_Delta_V;
???
??? /* Optional conversion to commonly used temperature units */
??? double Centigrade = Kelvin - 273.15;
??? double Fahrenheit = (Centigrade * 9.0 / 5.0) + 32;

2.10) 測(cè)量外部電壓輸入AUX1、AUX2、BAT1、BAT2和溫度
表9. ADC測(cè)量命令序列 DEMO1234 Command
?Action (Triggered by A/D3210 Bits) SPI data in
?
T MB
?Measure BAT1/4, BAT2/4, AUX1, AUX2, TEMP1, TEMP2 with 12-bit resolution and 3.5μs conversion rate 0x0040 0x2f01

0x8005 0x0000

0x8006 0x0000

0x8007 0x0000

0x8008 0x0000

0x8009 0x0000

0x800a 0x0000
?
T W AC 2f01
?Trigger ADC scan of BAT1-2, AUX1-2, TEMP1-2;
ADC control word 0x2f01 means:
ADC_control_wr_demand_scan
ADC_control_ AD1011 /* measure AUX1 etc. */
ADC_control_RES11 /* 12-bit resolution */
ADC_control_AVG00 /* no averaging */
ADC_control_CNR00 /* conversion rate 3.5μs */
ADC_control_RFV /* RFV=1: VREF=2.5V */ 0x0040 0x2f01
?
T R B1
?Read BAT1 result BAT1 _code 0x8005 0x0000
?
T R B2
?Read BAT2 result BAT2_code 0x8006 0x0000
?
T R A1
?Read AUX1 result AUX1 _code 0x8007 0x0000
?
T R A2
?Read AUX2 result AUX2 _code 0x8008 0x0000
?
T R T1
?Read TEMP1 result TEMP1 _code 0x8009 0x0000
?
T R T2
?Read TEMP2 result TEMP2 _code 0x800a 0x0000
?

3) 觸摸屏實(shí)例
下面的例子解釋了怎樣使用DEMO1234.EXE程序來(lái)獲得觸摸屏數(shù)據(jù)。

3.1) 低成本商用觸摸屏
在互聯(lián)網(wǎng)上搜索"PDA Digitizer/Glasstop"，尋找合適的替代觸摸屏。高清觸摸屏玻璃的價(jià)格范圍在50美元至10美元之間，價(jià)格取決于型號(hào)以及玻璃是否全部貼在顯示屏上。

3.2) 連接觸摸屏和評(píng)估板
MAX1234評(píng)估板提供突出插頭H5/H6來(lái)連接10mm柔性電纜或者長(zhǎng)度更短的電纜。H6連接器的間距是0.5mm，比實(shí)際觸摸屏柔性電纜間距更精細(xì)。把柔性電纜插入H6，上鎖，選擇位于四條柔性電纜中每一電纜中心位置的H5引腳。跳接器連接H5和標(biāo)有U1的X+、Y+、X-以及Y-測(cè)試點(diǎn)。

3.3) 檢驗(yàn)觸摸屏的連接
第一次連接觸摸屏?xí)r，通過下面的步驟來(lái)驗(yàn)證X和Y連接是否正確?？梢杂袔讉€(gè)觸摸屏交叉連接，但大部分不會(huì)正常工作。在這些例子中，我們假設(shè)X- = left，X+ = right，Y- = top，Y+ = bottom。

表10. 觸摸屏物理連接驗(yàn)證命令序列 DEMO1234 Command
?Action SPI data in
?Verification
? Connect DVM to X+/GND????
T MD
?No measurement; drive Y+,Y- 0x0040 0x3701
?
?Touch top left? X+ = approx. Y-
?Touch top right? X+ = approx. Y-
?Touch bottom left? X+ = approx. Y+
?Touch bottom right? X+ = approx. Y+
?Connect DVM to Y+/GND??
T ME
?No measurement; drive X+,X- 0x0040 0x3b01
?
?Touch top left? Y+ = approx. X-
?Touch top right? Y+ = approx. X+
?Touch bottom left? Y+ = approx. X-
?Touch bottom right? Y+ = approx. X+

表11. 糾正觸摸屏連接問題 Symptom Correction
Touch coordinates are mirrored top-to-bottom Swap the Y+ and Y- connections
Touch coordinates are mirrored left-to-right Swap the X+ and X- connections
Touch coordinates are rotated 180 degrees Swap the X+ and X- connections, and swap the Y+ and Y- connections
Touch coordinates are mirrored diagonally Swap the X+ and Y+ connections, and swap the X- and Y- connections
Touch coordinates do not seem to track, and the distortion is not a simple flip/rotate/mirror transformation Swap the X+ and Y+ connections;
if distortion persists, swap the X+ and Y- connections;
if distortion still persists, disconnect touch screen and use DVM to verify X+ to X- resistance and Y+ to Y- resistance;
verify with no touch X+ and X- are isolated from Y+ and Y-

3.4) 檢測(cè)觸摸屏的操作：根據(jù)需要掃描
在配置MAX1234檢測(cè)觸摸屏操作，根據(jù)需要數(shù)字化接觸屏的位置時(shí)，寫入寄存器0x40 (ADC控制)，其PENSTS=0，ADSTS=0 (請(qǐng)參考MAX1233/MAX1234數(shù)據(jù)資料的表6)。讀取寄存器0x00 (X軸)后，檢測(cè)到后續(xù)的觸摸屏操作時(shí)，/PENIRQ信號(hào)鎖存至低電平，在寫入ADC控制寄存器測(cè)量X、Y軸之前，保持低電平。

表12. 觸摸屏檢測(cè)命令序列：根據(jù)需要掃描 DEMO1234 Command
?Action SPI data in
?Verification
T W AC 0b01
?Demand scan 0x0040 0x0b01
?
T R AX
?Read conversion result register X 0x8000 0x0000
?
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 1
?Touch the touch screen??
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 0
T M2
?Measure X,Y,Z1,Z2 0x0040 0x0b01

0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 1
?Touch and hold the touch screen??
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 0
T M2
?Measure X,Y,Z1,Z2 0x0040 0x0b01

0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 0
T M2
?Measure X,Y,Z1,Z2 0x0040 0x0b01

0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 0
?Release the touch screen??
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 0
T M2
?Measure X,Y,Z1,Z2 0x0040 0x0b01

0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?
P R 6
?Read PENIRQ-bar pin status? PENIRQ = 1

3.5) 檢測(cè)觸摸屏操作：自動(dòng)掃描
在檢測(cè)觸摸屏操作，配置MAX1234，自動(dòng)數(shù)字化觸摸屏的接觸位置時(shí)，寫入寄存器0x40 (ADC控制)，其PENSTS=1，ADSTS=0 (請(qǐng)參考MAX1233/MAX1234數(shù)據(jù)資料的表6)。第一次接觸屏幕時(shí)，/PENIRQ信號(hào)暫時(shí)變?yōu)榈碗娖?，并在讀取X寄存器之前不會(huì)變化。

表13. 觸摸屏檢測(cè)命令序列：自動(dòng)掃描 DEMO1234 Command
?Action SPI data in
?Verification
?Optional: connect oscilloscope to PENIRQ-bar??
I C 1 3
?Configure PENIRQ-bar pulse accumulator: falling-edge trigger??
I 0 1
?Reset the pulse accumulator??
I R 1
?Read the number of times PENIRQ-bar has pulsed low? count = 0
T W AC 8bff
?Wait for touch, then scan X,Y,Z1,Z2 0x0040 0x8bff
?
?Touch the touch screen? PENIRQ pulse
I R 1
?Read the number of times PENIRQ-bar has pulsed low? count has increased
T R P
?Read X,Y,Z1,Z2 conversion results 0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?
?Touch the touch screen? PENIRQ pulse
I R 1
?Read the number of times PENIRQ-bar has pulsed low? count has increased
T R P
?Read X,Y,Z1,Z2 conversion results 0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?
?Touch the touch screen? PENIRQ pulse
I R 1
?Read the number of times PENIRQ-bar has pulsed low? count has increased
T R P
?Read X,Y,Z1,Z2 conversion results 0x8000 0x0000

0x8001 0x0000

0x8002 0x0000

0x8003 0x0000
?

4) 鍵盤和通用輸入/輸出引腳
下面的例子介紹了怎樣使用DEMO1234.EXE程序來(lái)掃描鍵盤，怎樣使用GPIO鍵盤掃描引腳。

4.1) 配置鍵盤和GPIO引腳
GPIO控制寄存器將每個(gè)C1–C4和R1–R4引腳分別配置為輸入、輸出或者是鍵盤的一部分(請(qǐng)參考MAX1233/MAX1234數(shù)據(jù)資料的表26和表27)。此外，寫入GPIO上拉禁止寄存器，將輸出引腳配置為開漏輸出。

表14. 鍵盤和GPIO配置實(shí)例 DEMO1234 Command
?Action SPI data in
?
T W GC FFFF
?Keypad: none;
GPIO outputs: C4,C3,C2,C1,R4,R3,R2,R1;
GPIO inputs: none 0x004f 0xffff
?
T W GC FF00
?Keypad: none;
GPIO outputs: none;
GPIO inputs: C4,C3,C2,C1,R4,R3,R2,R1 0x004f 0xff00
?
T W GC 0000
?Keypad: (C4,C3,C2,C1) x (R4,R3,R2,R1);
GPIO outputs: none;
GPIO inputs: none 0x004f 0x0000
?
T W GC C8C0
?Keypad: (C2,C1) x (R3,R2,R1);
GPIO outputs: C4,C3;
GPIO input: R4 0x004f 0xc8c0
?
T W GP 4000
?GPIO pullup disable: C3 0x004e 0x4000
?

4.2) 讀寫GPIO引腳
GPIO數(shù)據(jù)寄存器讀取GPIO輸入引腳，寫入GPIO輸出引腳。注意：在這些例子中，C3、C4和R4是引腳名稱，而不是元件名稱。

表15. GPIO實(shí)例 DEMO1234 Command
?Action SPI data in
?Verification
T W GC C8C0
?Keypad:
(C2,C1) x (R3,R2,R1);
GPIO outputs: C4,C3;
GPIO input: R4 0x004f 0xc8c0
?
T W GP 4000
?GPIO pullup disable: C3 0x004e 0x4000
?
?Connect external resistor between C3 pin and DVDD??
?Connect DVM to C4 pin??
T W GD 8000
?GPIO write C4 = 1 0x000f 0x8000
?C4 pin = high
T W GD 0000
?GPIO write C4 = 0 0x000f 0x0000
?C4 pin = low
T W GD 8000
?GPIO write C4 = 1 0x000f 0x8000
?C4 pin = high
T W GD 0000
?GPIO write C4 = 0 0x000f 0x0000
?C4 pin = low
?Connect DVM to C3 pin??
T W GD 4000
?GPIO write C3 = 1 0x000f 0x4000
?C3 pin = high
T W GD 0000
?GPIO write C3 = 0 0x000f 0x0000
?C3 pin = low
T W GD 4000
?GPIO write C3 = 1 0x000f 0x4000
?C3 pin = high
T W GD 0000
?GPIO write C3 = 0 0x000f 0x0000
?C3 pin = low
?Connect R4 pin to DVDD??
T R GD
?GPIO read 0x800f 0x0000
?Buffer = 0x0800
?Connect R4 pin to GND??
T R GD
?GPIO read 0x800f 0x0000
?Buffer = 0x0000

4.3) 檢測(cè)按鍵：自動(dòng)掃描
可以配置鍵盤控制寄存器在探測(cè)到有按鍵按下時(shí)，自動(dòng)掃描鍵盤。

表16. 按鍵命令序列：自動(dòng)掃描 DEMO1234 Command
?Action SPI data in
?Verification
?Optional: connect oscilloscope to KEYIRQ-bar??
I C 0 3
?Configure KEYIRQ-bar pulse accumulator: falling-edge trigger??
I 0 0
?Reset the pulse accumulator??
I R 0
?Read the number of times KEYIRQ-bar has pulsed low? count = 0
T W GC 0000
?Keypad:
(C4,C3,C2,C1) x (R4,R3,R2,R1);
GPIO outputs: none;
GPIO inputs: none 0x004f 0x0000
?
T W KC bf00
?Wait for keypress;
maximum debounce and hold times 0x0041 0xbf00
?
?Press and release R1C1 (key "1")? KEYIRQ pulse
I R 0
?Read the number of times KEYIRQ-bar has pulsed low? count has increased
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0001 = R1C1 key
?Press and release R2C2 (key "5")? KEYIRQ pulse
I R 0
?Read the number of times KEYIRQ-bar has pulsed low? count has increased
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0020 = R2C2 key
?Press and release R3C2 (key "8")? KEYIRQ pulse
I R 0
?Read the number of times KEYIRQ-bar has pulsed low? count has increased
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0040 = R3C2 key

4.4) 從鍵盤中屏蔽單個(gè)按鍵
使用鍵盤屏蔽寄存器和鍵盤2結(jié)果寄存器來(lái)屏蔽每個(gè)按鍵。屏蔽掉的按鍵被掃描至KPD寄存器，但是不在鍵盤2結(jié)果寄存器中報(bào)告。

表17. 按鍵命令序列：屏蔽單個(gè)按鍵 DEMO1234 Command
?Action SPI data in
?Verification
T W GC 0000
?Keypad:
(C4,C3,C2,C1) x (R4,R3,R2,R1);
GPIO outputs: none;
GPIO inputs: none 0x004f 0x0000
?
T W KC bf00
?Wait for keypress;
maximum debounce and hold times 0x0041 0xbf00
?
T W KM 0020
?Mask only R2C2 key 0x0050 0x0020
?
?Press and release R1C1 (key "1")??
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0001 = R1C1 key
T R K2
?Read masked keypad result 0x8011 0x0000
?0x0001 = R1C1 key
?Press and release R2C2 (key "5")??
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0020 = R2C2 key
T R K2
?Read masked keypad result 0x8011 0x0000
?0x0000 = no key
?Press and release R3C2 (key "8")??
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0040 = R3C2 key
T R K2
?Read masked keypad result 0x8011 0x0000
?0x0040 = R3C2 key

4.5) 從鍵盤中屏蔽一列
使用鍵盤列寄存器來(lái)屏蔽所有列。不掃描屏蔽列，因此，KPD寄存器不會(huì)探測(cè)這些列中的按鍵。

表18. 按鍵命令序列：屏蔽鍵盤的一列 DEMO1234 Command
?Action SPI data in
?Verification
T W GC 0000
?Keypad:
(C4,C3,C2,C1) x (R4,R3,R2,R1);
GPIO outputs: none;
GPIO inputs: none 0x004f 0x0000
?
T W KC bf00
?Wait for keypress;
maximum debounce and hold times 0x0041 0xbf00
?
T W KK 2000
?Mask entire C2 column 0x0051 0x2000
?
?Press and release R1C1 (key "1")??
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0001 = R1C1 key
?Press and release R2C2 (key "5")??
T R KB
?Read raw keypad result 0x8004 0x0000
?(previous value)
?Press and release R3C2 (key "8")??
T R KB
?Read raw keypad result 0x8004 0x0000
?(previous value)
?Press and release R2C3 (key "6")??
T R KB
?Read raw keypad result 0x8004 0x0000
?0x0200 = R2C3 key

5) 電源管理
表19. 關(guān)斷命令 DEMO1234 Command
?Action SPI data in
?Verification
T W AC C000
?Power off ADC 0x0040 0xc000
?—
T W AC 0300
?Power off internal reference 0x0040 0x0300
?REF = not driven
T W DC 8000
?Disable DAC 0x0042 0x8000
?DACOUT = 0.0V
T W KC C000
?Power off keypad 0x0041 0xc000
?—

6) 菜單系統(tǒng)
全部源代碼實(shí)現(xiàn)下面的控制臺(tái)菜單系統(tǒng)，它連接至MINIQUSB+模塊。

CmodComm測(cè)試程序主菜單—在連接前
A) adjust timing parameters
L) CmodLog... functions
C) connect
D) Debug Messages
X) exit

對(duì)C (連接)命令的響應(yīng)
C
Hardware supports optimized native SMBus commands.

Board connected.

Got board banner: Maxim MINIQUSB V01.05.41 >
Firmware version is OK.
(configured for SPI auto-CS 4-byte mode) (SCLK=2MHz) ...

主菜單—連接后有效
T) Test the device
8) CmodP8Bus... functions
A) adjust timing parameters
L) CmodLog... functions
P) CmodPin... functions
S) CmodSpi... functions
M) CmodSMBus... functions
＄) CmodCommStringWrite list of hex codes

R) CmodBoardReset
D) Disconnect

測(cè)試菜單命令—連接后有效
R) Read register
W) Write register
M0) measure no measurement; configure reference
M1) measure X,Y
M2) measure X,Y,Z1,Z2
M3) measure X
M4) measure Y
M5) measure Z1,Z2
M6) measure BAT1/4
M7) measure BAT2/4
M8) measure AUX1
M9) measure AUX2
MA) measure TEMP1
MB) measure BAT1/4,BAT2/4,AUX1,AUX2,TEMP1,TEMP2
MC) measure TEMP1,TEMP2
MD) no measurement; drive Y+,Y-
ME) no measurement; drive X+,X-
MF) no measurement; drive Y+,X-
.) Exit this menu

6.1) 寄存器讀/寫命令
表20. 讀取寄存器助記符 DEMO1234 Command
?Mnemonic SPI data in
?
T R A1
?Test Read AUX1 register 0x8007 0x0000
?
T R A2
?Test Read AUX2 register 0x8008 0x0000
?
T R AC
?Test Read ADC_control register 0x8040 0x0000
?
T R AX
?Test Read X register 0x8000 0x0000
?
T R AY
?Test Read Y register 0x8001 0x0000
?
T R AZ1
?Test Read Z1 register 0x8002 0x0000
?
T R AZ2
?Test Read Z2 register 0x8003 0x0000
?
T R B1
?Test Read BAT1 register 0x8005 0x0000
?
T R B2
?Test Read BAT2 register 0x8006 0x0000
?
T R DC
?Test Read DAC_control register 0x8042 0x0000
?
T R DD
?Test Read DAC_data register 0x800b 0x0000
?
T R GC
?Test Read GPIO_control register 0x804f 0x0000
?
T R GD
?Test Read GPIO_data register 0x800f 0x0000
?
T R GP
?Test Read GPIO_pullup register 0x804e 0x0000
?
T R K1
?Test Read KPDATA1 register 0x8010 0x0000
?
T R K2
?Test Read KPDATA2 register 0x8011 0x0000
?
T R KB
?Test Read KPD register 0x8004 0x0000
?
T R KC
?Test Read KEY_control register 0x8041 0x0000
?
T R KK
?Test Read KPCOLMASK register 0x8051 0x0000
?
T R KM
?Test Read KPKEYMASK register 0x8050 0x0000
?
T R T1
?Test Read TEMP1 register 0x8009 0x0000
?
T R T2
?Test Read TEMP2 register 0x800a 0x0000
?

表21. 寫入寄存器助記符 DEMO1234 Command
?Mnemonic SPI data in
?
T W AC hexValue
?Test Write ADC_control register 0x0040 hexValue
?
T W DC hexValue
?Test Write DAC_control register 0x0042 hexValue
?
T W DD hexValue
?Test Write DAC_data register 0x000b hexValue
?
T W GC hexValue
?Test Write GPIO_control register 0x004f hexValue
?
T W GD hexValue
?Test Write GPIO_data register 0x000f hexValue
?
T W GP hexValue
?Test Write GPIO_pullup register 0x004e hexValue
?
T W KC hexValue
?Test Write KEY_control register 0x0041 hexValue
?
T W KK hexValue
?Test Write KPCOLMASK register 0x0051 hexValue
?
T W KM hexValue
?Test Write KPKEYMASK register 0x0050 hexValue
?

表22. 觸摸屏測(cè)量命令序列 DEMO1234 Command
?Action (Triggered by A/D3210 Bits) SPI data in Sequence
?
T M1
?Measure X,Y 0x0040 0x07010x8000 0x00000x8001 0x0000
?
T M2
?Measure X,Y,Z1,Z2 0x0040 0x0b010x8000 0x00000x8001 0x00000x8002 0x00000x8003 0x0000
?
T M3
?Measure X 0x0040 0x0f010x8000 0x0000
?
T M4
?Measure Y 0x0040 0x13010x8001 0x0000
?
T M5
?Measure Z1,Z2 0x0040 0x17010x8002 0x00000x8003 0x0000
?
T MD
?No measurement; drive Y+,Y- 0x0040 0x3701
?
T ME
?No measurement; drive X+,X- 0x0040 0x3b01
?
T MF
?No measurement; drive Y+,X- 0x0040 0x3f01
?

6.2) 中斷和狀態(tài)引腳命令
表23. 引腳狀態(tài)讀取命令 DEMO1234 Command
?Action SPI data in
?
P R 5
?Read KEYIRQ-bar pin status N/A
I C 0 3
?Enable KEYIRQ-bar falling-edge trigger pulse accumulator N/A
I C 0 1
?Enable KEYIRQ-bar rising-edge trigger pulse accumulator N/A
I C 0 0
?Disable KEYIRQ-bar pulse accumulator N/A
I R 0
?Read the number of times KEYIRQ-bar has pulsed low N/A
I 0 0
?Clear the KEYIRQ-bar pulse accumulator N/A
P R 6
?Read PENIRQ-bar pin status N/A
I C 1 3
?Enable PENIRQ-bar falling-edge trigger pulse accumulator N/A
I C 1 1
?Enable PENIRQ-bar rising-edge trigger pulse accumulator N/A
I C 1 0
?Disable PENIRQ-bar pulse accumulator N/A
I R 1
?Read the number of times PENIRQ-bar has pulsed low N/A
I 0 1
?Clear the PENIRQ-bar pulse accumulator N/A
P R 7
?Read BUSY-bar pin status N/A

6.3) 加入到更新后的MINIQUSB+固件中的命令
表24. 更新后MINIQUSB+固件01.05.40支持的SPI命令 DEMO1234 Command
?Action CPOL CPHA CS-Bar Control AF Length
S C L0
?Configure SPI for CPOL=0 0 — GPIO-K9 1 byte
S C L1
?Configure SPI for CPOL=1 1 — GPIO-K9 1 byte
S C A0
?Configure SPI for CPHA=0 — 0 GPIO-K9 1 byte
S C A1
?Configure SPI for CPHA=1 — 1 GPIO-K9 1 byte
S C C0
?Configure SPI for 8-bit — — GPIO-K9 1 byte
S C C1
?Configure SPI for 8-bit auto-CS-bar — — Automatic 1 byte
S C C2
?Configure SPI for 16-bit auto-CS-bar — — Automatic 2 bytes
S C C3
?Configure SPI for 24-bit auto-CS-bar — — Automatic 3 bytes
S C C4
?Configure SPI for 32-bit auto-CS-bar — — Automatic 4 bytes
＄ 2 AE 00
?Configure SPI for 8-bit 0 0 GPIO-K9 1 byte
＄ 2 AE 01
?Configure SPI for 8-bit 0 1 GPIO-K9 1 byte
＄ 2 AE 02
?Configure SPI for 8-bit 1 0 GPIO-K9 1 byte
＄ 2 AE 03
?Configure SPI for 8-bit 1 1 GPIO-K9 1 byte
＄ 2 AE 08
?Configure SPI for 8-bit auto-CS-bar 0 0 Automatic 1 byte
＄ 2 AE 09
?Configure SPI for 8-bit auto-CS-bar 0 1 Automatic 1 byte
＄ 2 AE 0A
?Configure SPI for 8-bit auto-CS-bar 1 0 Automatic 1 byte
＄ 2 AE 0B
?Configure SPI for 8-bit auto-CS-bar 1 1 Automatic 1 byte
＄ 2 AE 18
?Configure SPI for 16-bit auto-CS-bar 0 0 Automatic 2 bytes
＄ 2 AE 19
?Configure SPI for 16-bit auto-CS-bar 0 1 Automatic 2 bytes
＄ 2 AE 1A
?Configure SPI for 16-bit auto-CS-bar 1 0 Automatic 2 bytes
＄ 2 AE 1B
?Configure SPI for 16-bit auto-CS-bar 1 1 Automatic 2 bytes
＄ 2 AE 28
?Configure SPI for 24-bit auto-CS-bar 0 0 Automatic 3 bytes
＄ 2 AE 29
?Configure SPI for 24-bit auto-CS-bar 0 1 Automatic 3 bytes
＄ 2 AE 2A
?Configure SPI for 24-bit auto-CS-bar 1 0 Automatic 3 bytes
＄ 2 AE 2B
?Configure SPI for 24-bit auto-CS-bar 1 1 Automatic 3 bytes
＄ 2 AE 38
?Configure SPI for 32-bit auto-CS-bar 0 0 Automatic 4 bytes
＄ 2 AE 39
?Configure SPI for 32-bit auto-CS-bar 0 1 Automatic 4 bytes
＄ 2 AE 3A
?Configure SPI for 32-bit auto-CS-bar 1 0 Automatic 4 bytes
＄ 2 AE 3B
?Configure SPI for 32-bit auto-CS-bar 1 1 Automatic 4 bytes
＄ 2 AF xx
?Perform an 8-bit SPI transfer (CS-bar = GPIO or auto-CS-bar = 1-byte) — — — 1 byte
＄ 3 AF xx xx
?Perform a 16-bit SPI transfer (requires auto-CS-bar = 2-byte mode) — — — 2 bytes
＄ 4 AF xx xx xx
?Perform a 24-bit SPI transfer (requires auto-CS-bar = 3-byte mode) — — — 3 bytes
＄ 5 AF xx xx xx xx
?Perform a 32-bit SPI transfer (requires auto-CS-bar = 4-byte mode) — — — 4 bytes
＄ 2 F9 0
?Drive CS-bar pin low — — GPIO-K9 —
＄ 2 F9 1
?Drive CS-bar pin high — — GPIO-K9 —

表25. 更新后MINIQUSB+固件01.05.41中的中斷脈沖累加器命令 DEMO1234 Command
?Action Int GPIO Input Firmware Command
?
＄ 2 C3 00
?Query which of the C3 commands are supported; the return value is a 2-byte bitmap of commands C300 to C30F, msb first — — C3 00
?
I Q 0
?Query configuration of pulse accumulator INT0 GPIO-K5 C3 01 00
?
I Q 1
?Query configuration of pulse accumulator INT1 GPIO-K6 C3 01 01
?
I Q 2
?Query configuration of pulse accumulator INT2 GPIO-K7 C3 01 02
?
I Q 3
?Query configuration of pulse accumulator INT3 GPIO-K8 C3 01 03
?
I C 0 0
?Configure pulse accumulator: disable interrupt INT0 GPIO-K5 C3 02 00 00
?
I C 1 0
?Configure pulse accumulator: disable interrupt INT1 GPIO-K6 C3 02 01 00
?
I C 2 0
?Configure pulse accumulator: disable interrupt INT2 GPIO-K7 C3 02 02 00
?
I C 3 0
?Configure pulse accumulator: disable interrupt INT3 GPIO-K8 C3 02 03 00
?
I C 0 1
?Configure pulse accumulator: rising-edge trigger INT0 GPIO-K5 C3 02 00 01
?
I C 1 1
?Configure pulse accumulator: rising-edge trigger INT1 GPIO-K6 C3 02 01 01
?
I C 2 1
?Configure pulse accumulator: rising-edge trigger INT2 GPIO-K7 C3 02 02 01
?
I C 3 1
?Configure pulse accumulator: rising-edge trigger INT3 GPIO-K8 C3 02 03 01
?
I C 0 3
?Configure pulse accumulator: falling-edge trigger INT0 GPIO-K5 C3 02 00 03
?
I C 1 3
?Configure pulse accumulator: falling-edge trigger INT1 GPIO-K6 C3 02 01 03
?
I C 2 3
?Configure pulse accumulator: falling-edge trigger INT2 GPIO-K7 C3 02 02 03
?
I C 3 3
?Configure pulse accumulator: falling-edge trigger INT3 GPIO-K8 C3 02 03 03
?
I R 0
?Read pulse accumulator INT0 GPIO-K5 C3 03 00
?
I R 1
?Read pulse accumulator INT1 GPIO-K6 C3 03 01
?
I R 2
?Read pulse accumulator INT2 GPIO-K7 C3 03 02
?
I R 3
?Read pulse accumulator INT3 GPIO-K8 C3 03 03
?
I 0 0
?Clear pulse accumulator INT0 GPIO-K5 C3 04 00
?
I 0 1
?Clear pulse accumulator INT1 GPIO-K6 C3 04 01
?
I 0 2
?Clear pulse accumulator INT2 GPIO-K7 C3 04 02
?
I 0 3
?Clear pulse accumulator INT3 GPIO-K8 C3 04 03
?
I S 0 xx
?Set pulse accumulator count xx = 0 to 255 INT0 GPIO-K5 C3 05 00 xx
?
I S 1 xx
?Set pulse accumulator count xx = 0 to 255 INT1 GPIO-K6 C3 05 01 xx
?
I S 2 xx
?Set pulse accumulator count xx = 0 to 255 INT2 GPIO-K7 C3 05 02 xx
?
I S 3 xx
?Set pulse accumulator count xx = 0 to 255 INT3 GPIO-K8 C3 05 03 xx
?