Hardware Introduction Tiger City IMX Industrial Computer with Linux OS The Tiger City IMX minicomputer uses Linux operating systems and is equipped with several communication interfaces such as: Ethernet, USB 2.0, HDMI, GSM, RS232, RS485, 1-Wire and multiple analog-digital inputs and outputs. It can also be configured to include a Wi-Fi module and encryption modules that increase the security of the device. The casing enables installation on the DIN rail. The front panel has switches, an OLED display and a joystick for manual control of the device operation. Specifications of the device Power: voltage 12-24 VDC +-20%, maximum power 25 W, reverse polarity protection SoM: VAR-SOM-MX8M-MINI Core: NXP’s i.MX 8M Mini with 1.6 GHz Quad-core ARM Cortex-A53 and 400 MHz Cortex-M4 real-time processor Timing: 1.6 GHz RAM: 2 GB DDR4 Flash eMMC: 16 GB 1x microSD connector 1x microHDMI 1.3a (optional) 1x microUSB 2.0 HOST / OTG, max. 500 mA (optional) 1x USB-A 2.0 HOST, max. 1 A 1x modem GSM SIM7600E + microSIM (optional) 1x 1-Wire (optional) 7x DIO - digital input/output, max. 30 V 4x UIO - universal analog-digital input/output (temperature measurement with sensors, e.g.: Pt1000, Ni1000, KTY, NTC, current, voltage and resistance sensors), max. 20 V (optional) 5x DI - digital input (3 x DI), max. 30 V (optional) 2x RS232, baudrate 50-115200 bps 2x RS485, baudrate 50-115200 bps (4x optional) 1x Ethernet 10/100 Mbps - RJ45 connector 1x Wi-Fi® / 2.4G module (optional) 1x secure element (optional) 1x display OLED 0.87" 128x32 px black&white (optional) 1x Joystick (optional) RTC (optional), buzzer, EEPROM TPM (optional) Software watchdog   Dimensions of the device The space that the device occupies can be approximated to a cube of the following dimensions: 119 mm x 101 mm x 22.5 mm.   Simplified block diagram Technical Diagrams Tiger City IMX Industrial Computer with Linux OS Enclosure Placement of peripherals Detailed connections diagram External Interfaces Tiger City IMX Industrial Computer with Linux OS USB Serial ports 1-Wire HDMI ETHERNET‎ GSM MicroSD slot Wi-Fi‎/2.4G Digital inputs Digital inputs/outputs Universal inputs/outputs USB The device is equipped with 2 USB connectors. USB1 MicroUSB connector for USB 2.0 is placed on the front panel. The interface can work in both host and device modes. The signal on the connector can be changed with a switch. The maximal current of the connector is 500 mA. MicroUSB connector location USB1 connection diagram Description Processor pin Default function 5 V USB voltage F22 USB1_VBUS USB data differential pair negative A22 USB1_D_N USB data differential pair positive B22 USB1_D_P USB on the go AB10 USB1_OTG_PWR UART4 Device name: /dev/ttymxc3 Signal Processor pin Default function Receive (UART4 RX) F19 UART4_RXD Transmit (UART4 TX) F18 UART4_TXD USB2 USB-A connector for USB 2.0 is placed on the side of the device with the interface set up in the host mode. The maximal current of the connector is 1 A. USB-A connector location USB2 connection diagram Description Processor pin Default function USB power switch control F23 USB2_VBUS USB data differential pair negative A23 USB2_D_N USB data differential pair positive B23 USB2_D_P Serial ports The device is equipped with 3 serial port connectors. RS485-1/2 Baud rate: 50-115200 bps. Location of the RS485-1/2 connector Connector pin Description A1 RS485 A1 B1 RS485 B1 G Ground A2 RS485 A2 B2 RS485 B2 RS485-3/4 Baud rate: 50-115200 bps. Location of the RS485-3/4 connector Connector pin Description A3 RS485 A3 B3 RS485 B3 G Ground A4 RS485 A4 B4 RS485 B4 RS485-1/2/3/4 connections diagram //sprawdzić z Dmytro całkowitą rezystancję terminacji (rezystor + transoptor go załączający) SPI2 Signal Processor pin Default function Chip select 0 A6 SPI2_CS0 Chip select 1 AF12 SPI2_CS1 Chip select 2 AB19 SPI2_CS2 Master in slave out A8 SPI2_MISO Clock E6 SPI2_SCLK Master out slave in B8 SPI2_MOSI Expander B The RS485 1 & 2 lines are controlled from the B expander connected by the SPI2 interface with the CPU. Expander F The RS485 3 & 4 lines are controlled from the F expander connected by the SPI2 interface with the CPU. Expander E The termination resistors are controlled by signals output from the Expander E connected by the I2C3 interface with the CPU. RS232-1/2 Baud rate: 50-115200 bps. Location of the RS232-1/2 connector Connector pin Description T1 RS232 TX1 R1 RS232 RX1 G Ground T2 RS232 TX2 R2 RS232 RX2 RS232-1/2 connections diagram UART4 Device name: /dev/ttymxc3 Signal Processor pin Default function Receive (UART4 RX) F19 UART4_RXD Transmit (UART4 TX) F18 UART4_TXD UART1 Device name: /dev/ttymxc0 Signal Processor pin Default function Receive (UART1 RX) E14 UART1_RXD Transmit (UART1 TX) F13 UART1_TXD UART3 Device name: /dev/ttymxc2 Signal Processor pin Default function Receive (UART3 RX) E18 UART3_RXD Transmit (UART3 TX) D18 UART3_TXD 1-Wire The device is equipped with the 1-Wire interface operating with Maxim sensors. Connector 5 V outputs are secured with a 100 mA fuse. 1-Wire connector and pins  Connector pin Description 1W 1-Wire data 5V 1-Wire +5 V power G Ground 1-Wire connection diagram I2C2 Device name: /dev/i2c-1 Signal Processor pin Default function Clock D10 I2C2_SCL Data D9 I2C2_SDA 1-Wire bridge Part number: DS2484 HDMI The device is equipped with the micro HDMI standard connector located on the front panel. HDMI connector location Signal Processor pin Default function DSI_TX0_N A9 MIPI_DSI_TX0_N DSI_TX0_P B9 MIPI_DSI_TX0_P DSI_TX1_N A10 MIPI_DSI_TX1_N DSI_TX1_P B10 MIPI_DSI_TX1_P DSI_TX2_N A12 MIPI_DSI_TX2_N DSI_TX2_P B12 MIPI_DSI_TX2_P DSI_TX3_N A13 MIPI_DSI_TX3_N DSI_TX3_P B13 MIPI_DSI_TX3_P DSI_CLK_N A11 MIPI_DSI_CLK_N DSI_CLK_P B11 MIPI_DSI_CLK_P HDMI connection diagram DSI/HDMI Bridge Part number: LT8912B I2C4 Device name: /dev/i2c-3 Signal Processor pin Default function Clock D13 I2C4_SCL Data E13 I2C4_SDA I2C2 Device name: /dev/i2c-1 Signal Processor pin Default function Clock D10 I2C2_SCL Data D9 I2C2_SDA ETHERNET‎ The device is equipped with a RJ45 connector placed on the side of the device. The diode on the front panel indicates ETHERNET's operation. RJ45 connector location ETHERNET connection diagram GSM The device is equipped with the SIM7600E module connected with the miniPCIE connector. Its features: operation of protocols: CP, UDP, PPP, HTTP, FTP, MQTT, SMS, Mail GNSS (GPS, GLONASS, BeiDou) positioning the microSIM card can be installed the device can be expanded with an antenna LED on the front panel indicates GSM operation Device name: SIM7600E MicroSIM connector Function Processor pin Default function USB power switch control F23 USB2_VBUS USB data differential pair negative A23 USB2_D_N USB data differential pair positive B23 USB2_D_P GSM connection diagram USB HUB Part number: USB2533I-1080AEN I2C4 Device name: /dev/i2c-3 Signal Processor pin Default function Clock D13 I2C4_SCL Data E13 I2C4_SDA MicroSD slot The device is equipped with a microSD card slot, connected directly to the CPU. Function Processor pin Default function SD data line 0 AB23 SD2_DATA0 SD data line 1 AB24 SD2_DATA1 SD data line 2 V24 SD2_DATA2 SD data line 3 V23 SD2_DATA3 SD command line W24 SD2_CMD SD clock W23 SD2_CLK Wi-Fi‎/2.4G The SOM is equipped with a Wi-Fi/2.4G module and can be connected to the dedicated IPX antenna connector or expanded with a Wi-Fi antenna which takes the place of digital inputs no. 1 and 2. The module is dual-band and operates on the frequencies of 2.4 and 5 GHz in 802.11.ac/a/b/g/n standard. The antennas can also be connected directly to the GSM module depending on the current needs. Wi-Fi connections diagram Wi-Fi module Part number: Sterling-LWB5 Digital inputs The device is equipped with a 5-pin digital inputs (DI) connector with a maximum voltage of 30 V and a dry contact. Input signals connect directly to the CPU.  DIs location on the connector DI connector pin Processor pin User-space name DI1 AC22 gpiochip3 26 "DI1" DI2 AD23 gpiochip3 24 "DI2" DI3 AB22 gpiochip3 22 "DI3" DI4 AD15 gpiochip2 25 "DI4" DI5 AC13 gpiochip2 24 "DI5" DI circuit block schematic R1 - push-up resistor 47 kΩ Digital inputs/outputs The device is equipped with 7 digital input/output (DIO) connectors. They can operate as: digital input with a maximal voltage of 30 V and a dry contact digital Vin output with a maximal current of 200 mA DIOs location on the connector DIO connector pin Input Output User-space name Expander E pin User-space name Expander A pin DIO1 gpiochip5 9 24 gpiochip7 1 1 DIO2 gpiochip5 10 25 gpiochip7 2 2 DIO3 gpiochip5 11 28 gpiochip7 3 3 DIO4 gpiochip5 12 1 gpiochip7 4 4 DIO5 gpiochip5 13 2 gpiochip7 5 5 DIO6 gpiochip5 14 3 gpiochip7 6 6 DIO7 gpiochip5 15 4 gpiochip7 7 7 DIO circuit block schematic F1 - 200 mA fuse R1 - pull-up resistor 10 kΩ R2 - pull-up resistor 47 kΩ Expander E The circuit's inputs are connected to the expander E via the I2C3 interface. Expander A Outputs of the circuit are connected to the expander A via the SPI1 interface. Universal inputs/outputs The device is equipped with 4 universal analog-digital inputs/outputs (UIOs). They can operate as: DC voltage inputs for voltage in the range of 0-10 V with the input resistance of 100 kΩ current inputs for current in the range of 0-4-20 mA with the input resistance of 200 Ω current outputs with the range of 4-20 mA temperature inputs of sensors: Pt1000, Ni1000, KTY, NTC resistance inputs with the range of 0-5000 Ω dry contact inputs analog to digital converters with 24-bit resolution digital to analog converters with 12-bit resolution Voltage is measured using a 2-channel analog-to-digital converter with 24-bit resolution. A current value can be set using a 4-channel digital-to-analog converter. UIOs location on the connector Diagram of UIO circuit R1 - 200 Ω/1% measurement resistor R2 - 100 kΩ/1% measurement resistor R3 - switchable resistor for changing range of current sources (649 Ω/1% or 1,649 Ω/1%) User-space access Analog-Digital Converter A Device name: /sys/bus/iio/devices/iio:device0 Analog-Digital Converter B Device name: /sys/bus/iio/devices/iio:device1 Digital-Analog Converter A Device name: /sys/bus/iio/devices/iio:device2 Possible configurations Switching to particular modes of the circuit is realized by “Set voltage input”, “Set current input”, “Current enable”, “Set R3 resistance value” and “Set current value” signals. Configuration signal Modes of operation DI dry contact AI 0-10 V AI 0-4-20 mA AO 4-20 mA / temperature* / resistance Set voltage input 0 1 0 0 Set current input 0 1 0 1 Current enable 1 0 0 1 Set R3 resistance value 1 X X 1 or 0** Set current value 12-bit value*** X X 12-bit value*** * by measuring resistance ** 1 for 1,649 kΩ/1% or 0 for 649 Ω/1% resistor *** depends on the sensor (see examples for more) X - any value DI - digital input AI - analog input AO - analog output UIO connector pin Configuration signal Expander C pin UIO1 Current enable 20 Set voltage input 19 Set current input 27 Set R3 resistance value 21 UIO2 Current enable 3 Set voltage input 22 Set current input 28 Set R3 resistance value 4 UIO3 Current enable 23 Set voltage input 17 Set current input 1 Set R3 resistance value 18 UIO4 Current enable 26 Set voltage input 24 Set current input 2 Set R3 resistance value 25 Expander C The circuit's inputs are connected to the expander C via the I2C2 interface. I2C3 Device name: /dev/i2c-2 Signal Processor pin Default function Clock E10 I2C3_SCL Data F10 I2C3_SDA I2C2 Device name: /dev/i2c-1 Signal Processor pin Default function Clock D10 I2C2_SCL Data D9 I2C2_SDA Internal Devices Tiger City IMX Industrial Computer with Linux OS Internal expansion connector Watchdog + reset EEPROM‎‎ FLASH RTC ESP32 microcontroller TPM 2.0 Secure element TO136 Buzzer Internal expansion connector Part number: FH1234-221CWG0MUT01 Internal expansion connector connections diagram Internal expansion connector connections table Connector pin Description 1 GND 2 VIN 3 GND 4 SPI1 MOSI 5 GND 6 SPI1 SCLK 7 GND 8 SPI1 MISO 9 GND 10 RTC battery power supply 11 External watchdog reset 12 NC 13 GND 14 NC 15 NC 16 NC 17 GPIO4 IO25 18 GND 19 GPIO1 IO07 20 GPIO4 IO21 21 GPIO5 IO09 22 Global reset 23 GND 24 I2C3 SDA 25 I2C3 SCL 26 GND 27 +3V3 28 GND 29 USB3 positive pole 30 USB3 negative pole 31 GND 32 +20V 33 UIO reset 34 NC 35 NC 36 +1V8 37 +1V8 38 GND 39 +5V 40 +5V 41 GND 42 GND 43 VIN 44 GND Watchdog + reset The device is equipped with a watchdog and a reset circuit. Watchdog and reset circuit connections diagram CPU connections table Signal Default function User-space name  ESP32_WDI GPIO1_IO01 gpiochip0 1 ESP32_WDI SOM_GLOB_NRST GPIO5_IO02 gpiochip4 2 GLOBAL_NRST GPIO0 GPIO3_IO22 gpiochip2 22 ESP_GPIO0 GPIO2 GPIO3_IO20 gpiochip2 20 ESP_GPIO2 ESP_CHIP_PU GPIO4_IO20 gpiochip3 20 ESP_CHIP_PU ESP32 reset The device is equipped with an ESP32 microcontroller as a watchdog. EEPROM‎‎ The device is equipped with 2 EEPROM memory modules. EEPROM B is read-only and reserved for the producer's purposes. EEPROM device Part number: M24C02-RMC6 EEPROM A connections table EEPROM pin Description User-space name 1 Address pin 0 (GND) X 2 Address pin 1 (+3V3) X 3 Address pin 2 (+3V3) X 5 I2C2 data X 6 I2C2 clock X 7 EEPROM write-protect gpiochip0 2 EEPROM B (EEPROM SN) connections table EEPROM pin Description User-space name 1 Address pin 0 (GND) X 2 Address pin 1 (+3V3) X 3 Address pin 2 (GND) X 5 I2C2 data X 6 I2C2 clock X 7 EEPROM write-protect (pull-up) X EEPROM connection diagram User-space access EEPROM device name:  /sys/bus/nvmem/devices/1-00561 EEPROM device address: 0x56 I2C2 EEPROMs A and B are connected to the CPU with the I2C2 interface. FLASH Part number: W25Q64JVSSIQ FLASH connections table FLASH pin Description User-space name 1 SPI1_CS0 gpiochip2 21 2 SPI1_MISO X 3 SPI1_WP X 5 SPI1_MOSI X 6 SPI1_SCLK X 7 SPI1_HOLD X FLASH connection diagram User-space access FLASH device name: /dev/mtdblock0 SPI1 FLASH is connected to the CPU with the SPI1 interface. RTC The device is equipped with a real-time clock operating at 32.768 kHz with a tolerance of 20 ppm. The RTC clock is connected to a DR2032 battery which serves as its power supply. RTC device Part number: DS1338 RTC connection diagram User-space access Device name: /sys/class/rtc/rtc0 Device address: 0x68 RTC connections table RTC pin Description 1 Clock oscillator pin no. 1 2 Clock oscillator pin no. 2 3 Battery power pin 5 I2C3 data 6 I2C3 clock I2C3 The real-time clock is connected to the CPU with the I2C3 interface. ESP32 microcontroller The device is equipped with an internal ESP32 microcontroller that can be used for internal purposes. ESP32 device Part number: ESP32-DOWD ESP32 connections table ESP32 pin Description 8 ESP_P_DETECT 9 ESP_CHIP_PU 14 ESP32_WDT_EN 15 ESP32_WDI 22 ESP_GPIO2 23 ESP_GPIO0 24 RESET_WDT 25 LED_ESP 26 VDD_SDIO 28 ESP_SPI_HD 29 ESP_SPI_WP 30 ESP_SPI_CS0 31 ESP_SPI_CLK 32 ESP_SPI_Q 33 ESP_SPI_D 38 I2C4_SCL 39 I2C4_SDA 40 ESP_CONSOLE_RX 41 ESP_CONSOLE_TX ESP32 connections diagram CPU connections table Signal CPU pin Default function User-space name ESP_GPIO_0 AC14 GPIO3_IO22 gpiochip2 22 ESP_GPIO_2 AC15 GPIO3_IO20 gpiochip2 20 ESP32_WDI AF14 GPIO1_IO01 gpiochip0 1 ESP32_WDT_EN AF13 GPIO1_IO03 gpiochip0 3 I2C4 The microcontroller is connected to the CPU via the I2C4 interface. UART3 The microcontroller is connected to the CPU via the UART3 interface. TPM 2.0 The device is equipped with a trusted platform module in 2.0 standard. TPM device Part number: SLM9670 TPM connections table TPM pin Description 17 Reset 18 TPM_IRQ 19 SPI2 clock 20 SPI2 chip select 0 21 SPI2 master out slave in 24 SPI2 master in slave out User-space access Device name: /sys/class/tpm TPM connection diagram CPU connections table Signal CPU pin Default function User-space name TPM_IRQ AC24 GPIO4_IO23 gpiochip3 23 SPI2_CS0_TPM A6 GPIO5_IO13 gpiochip4 13 SPI2 The trusted platform module is connected to the CPU with the SPI2 interface. Secure element TO136 The device is equipped with a secure element that can be used for data encoding. Secure element device Part number: IDEMIA TO136 Secure element connections table Secure element pin Description 1 I2C4 clock 2 I2C4 data 3 +3V3 6 IDLE/BUSY state report User-space access Device address: 0x50 Secure element connections diagram Expander E The secure element is connected to the Expander E connected to the CPU via the I2C3 interface. I2C4 The secure element is connected to the CPU via the I2C4 interface. Buzzer The device is equipped with a buzzer. Buzzer device Part number: LD-BZEG-0905 User-space access Device name:  gpiochip3 7 Label: "BUZZER" Buzzer connection diagram Front Panel Tiger City IMX Industrial Computer with Linux OS View of the front panel Components of the front panel DIP switches Signal LEDs OLED display Joystick Reset button DIP switches The device has DIP switches on the front panel which enable the control of various key functions such as: booting mode choice microUSB signal choice choosing Linux console or RS232 signal user-written code DIP switches placement on the front panel Switch options Switch No. Positions Description 1 OFF - eMMC boot ON - SD card boot Boot select - switching between booting device 2 OFF - USB1 OTG ON - UART4 (Linux console) USB select - microUSB signal choice 3 OFF - UART1 (SOM user) ON - UART4 (Linux console) RS232 - SOM UART RS232 select 4 OFF - UART2 RS232 user ON - ESP32 console RS232 - SOM UART RS232/ESP32 select 5 Unassigned Currently not used 6-8 OFF/ON User options Connections diagram Expander D User-defined DIP switch options are connected to the expander D which is connected to the CPU via the I2C3 interface. USB1 The USB MUX select 1 and the USB MUX select 2 signals are connected to the multiplexer A associated with USB1. Signal LEDs The device is equipped with 8 LEDs. 2 of these LEDs are placed on the mainboard, while the other 6 are on the front panel of the HMI board. LEDs location LEDs connections Description User-space name Label Power LED gpiochip6 9 "LED_5V" CPU LED gpiochip0 3 "LED_MAINBOARD" User LED 1 G gpiochip6 10 "LED3_GREEN" User LED 1 R gpiochip6 5 "LED3_RED" User LED 1 B gpiochip6 12 "LED3_BLUE" User LED 2 G gpiochip6 13 "LED4_GREEN" User LED 2 R gpiochip6 11 "LED4_RED" User LED 2 B gpiochip6 15 "LED4_BLUE" LED connection diagram ESP32 microcontroller ESP LED is connected directly to the ESP32 microcontroller. GSM GSM LED is connected directly to the GSM modem. ETHERNET‎ ETH activity LED and ETH link LED are connected directly to the ETHERNET physical layer. Expander D Power LED, User LED 1 and User LED2 are connected to the expander D which is connected to the CPU via the I2C3 interface. OLED display The device is equipped with a 0.87” black and white display with a resolution of 128x32 px. OLED display placement OLED device Part number:  SCE087002-V01 OLED connections table OLED pin Description User-space name RES# RESET  X SCL I2C3 clock  X SDA I2C3 data  X VCC OLED ON/OFF gpiochip6 14, "OLED_EN" OLED connections diagram Expander D The OLED display is connected to Expander D which is connected to the CPU via the I2C3 interface. I2C3 The OLED display is directly connected to the CPU via the I2C3 interface. Joystick The device is equipped with a joystick for controlling its functions. Placement Device Part number: INT-1500D Connections table Joystick signal Expander D pin User-space name Label Right 20 gpiochip6 3 "JOY_RIGHT" Up 18 gpiochip6 1 "JOY_UP" Left 17 gpiochip6 0 "JOY_LEFT" Down 19 gpiochip6 2 "JOY_DOWN" Push 21 gpiochip6 4 "JOY_PUSH" Connection diagram Expander D Joystick is connected to the Expander D which is connected to the CPU via the I2C3 interface. Reset button The device has a reset button on the front panel. Reset button location Connections diagram Watchdog + reset The reset button is connected directly to the reset circuit. Expanders Tiger City IMX Industrial Computer with Linux OS Expander A Expander B Expander C Expander D Expander E Expander F Expander A Part number: 74HC595BQ Expander A diagram Expander A pins description Pin Type Usage User-space name Description 1 Q1 DO1 gpiochip8 1 Digital output 1 2 Q2 DO2 gpiochip8 2 Digital output 2 3 Q3 DO3 gpiochip8 3 Digital output 3 4 Q4 DO4 gpiochip8 4 Digital output 4 5 Q5 DO5 gpiochip8 5 Digital output 5 6 Q6 DO6 gpiochip8 6 Digital output 6 7 Q7 DO7 gpiochip8 7 Digital output 7 9 Q7S NC X Not connected 10 MR/ NRST_GLOBAL X Reset 11 SHCP SPI1_SCLK X SPI clock 12 STCP SPI1_CS1 X SPI chip select 13 OE/ GND X Output enable 14 DS SPI1_MOSI X SPI master out slave in 15 Q0 MUX_DIO_SEL gpiochip8 0 MUX_PWM selection signal 16 VCC +3V3 X Power supply SPI1 Signal Processor pin Default function Chip select 0 AD18 SPI1_CS0 Chip select 1 AG23 SPI1_CS1 Master in slave out A7 SPI1_MISO Clock D6 SPI1_SCLK Master out slave in B7 SPI1_MOSI Expander B Part number:  SC16IS752IBS Expander B diagram Expander B pins description Pin Type Usage User-space name Description 1 RXA(I) RS485_UART1_RX X RS485 UART1 RX 2 RESET/ RS485_NRST X Reset 3 XTAL1(I) TXCO_OUT X Oscillator output 4 XTAL2(O) NC X Not connected 5 VDD +3V3 X Power supply 6 I2C / SPI/ GND X Ground 7 CS/ / A0 SPI2_CS1 X SPI chip select 8 SI / A1 SPI2_MOSI X SPI master out slave in 9 SO SPI2_MISO X SPI master in slave out 10 SCL / SCLK SPI2_SCLK X SPI clock 11 SDA / VSS GND X Ground 12 VSS GND X Ground 14 IRQ/ RS485_INT X RS485 interrupt 15 CTSB/ NC X Not connected 16 RTSB/ RS485_UART2_RTS X RS485 UART2 RTS 17 GPIO0 / DSRB/ NC X Not connected 18 GPIO1 / DTRB/ NC X Not connected 19 GPIO2 / CDB/ NC X Not connected 20 GPIO3 / RIB/ NC X Not connected 22 TXB(O) RS485_UART2_TX X RS485 UART2 TX 23 RXB(I) RS485_UART2_RX X RS485 UART2 RX 24 GPIO4 / DSRA/ NC X Not connected 25 GPIO5 / DTRA/ NC X Not connected 26 GPIO6 / CDA/ NC X Not connected 27 GPIO7 / RIA/ NC X Not connected 30 RTSA/ RS485_UART1_RTS X RS485 UART1 RTS 31 CTSA/ NC X Not connected 32 TXA(O) RS485_UART1_TX X RS485 UART1 TX SPI2 Signal Processor pin Default function Chip select 0 A6 SPI2_CS0 Chip select 1 AF12 SPI2_CS1 Chip select 2 AB19 SPI2_CS2 Master in slave out A8 SPI2_MISO Clock E6 SPI2_SCLK Master out slave in B8 SPI2_MOSI Expander C Part number: MCP23017-E/ML Expander C diagram Expander C pins description Pin Port Type User-space name Description 1 GPB4 GPIO gpiochip5 12 UIO4 voltage 2 GPB5 GPIO gpiochip5 13 UIO4 current 3 GPB6 GPIO gpiochip5 14 UIO4 resistance 4 GPB7 GPIO gpiochip5 15 UIO3 resistance 5 VDD +3V3 X Power supply 6 VSS GND X Ground 7 NC NC X Not connected 8 SCK GPIO X I2C clock 9 SDA GPIO X I2C data 10 NC NC X Not connected 11 A0 GND X Address bit 0 12 A1 GND X Address bit 1 13 A2 GND X Address bit 2 14 RESET/ EXP2_NRST X Reset 15 INTB NC X Not connected 16 INTA NC X Not connected 17 GPA0 GPIO gpiochip5 0 UIO2 resistance 18 GPA1 GPIO gpiochip5 1 UIO1 resistance 19 GPA2 GPIO gpiochip5 2 UIO1 voltage 20 GPA3 GPIO gpiochip5 3 UIO2 voltage 21 GPA4 GPIO gpiochip5 4 UIO3 voltage 22 GPA5 GPIO gpiochip5 5 UIO1 current 23 GPA6 GPO gpiochip5 6 UIO4 I source 24 GPA7 GPIO gpiochip5 7 UIO3 current 25 GPB0 GPIO gpiochip5 8 UIO2 current 26 GPB1 GPO gpiochip5 9 UIO1 I source 27 GPB2 GPO gpiochip5 10 UIO2 I source 28 GPB3 GPO gpiochip5 11 UIO3 I source I2C2 Device name: /dev/i2c-1 Signal Processor pin Default function Clock D10 I2C2_SCL Data D9 I2C2_SDA Expander D Part number: MCP23017 Expander D diagram Expander D pins description Pin Port Type User-space name Description 1 GPB4 GPO gpiochip6 12 LED3 BLUE ON / OFF 2 GPB5 GPO gpiochip6 13 LED4 GREEN ON / OFF 3 GPB6 GPO gpiochip6 14 OLED ON / OFF 4 GPB7 GPO gpiochip6 15 LED4 BLUE ON / OFF 5 VDD +3V3 X Power supply 6 VSS GND X Ground 7 NC1 NC X Not connected 8 SCK GPIO X I2C clock 9 SDA GPIO X I2C data 10 NC2 NC X Not connected 11 A0 GND X Address bit 0 12 A1 GND X Address bit 1 13 A2 GND X Address bit 2 14 RESET/ NRST_GLOBAL X Reset 15 INTB HMI_IRQ X Interrupt B 16 INTA HMI_IRQ X Interrupt A 17 GPA0 GPI gpiochip6 0 Joystick left input 18 GPA1 GPI gpiochip6 1 Joystick up input 19 GPA2 GPI gpiochip6 2 Joystick down input 20 GPA3 GPI gpiochip6 3 Joystick right input 21 GPA4 GPI gpiochip6 4 Joystick push input 22 GPA5 GPO gpiochip6 5 LED3 RED ON / OFF 23 GPA6 GPI gpiochip6 6 DIP switch 6 input 24 GPA7 GPI gpiochip6 7 DIP switch 7 input 25 GPB0 GPI gpiochip6 8 DIP switch 8 input 26 GPB1 GPO gpiochip6 9 LED 5 V power supply ON / OFF 27 GPB2 GPO gpiochip6 10 LED3 GREEN ON / OFF 28 GPB3 GPO gpiochip6 11 LED4 RED ON / OFF I2C3 Device name: /dev/i2c-2 Signal Processor pin Default function Clock E10 I2C3_SCL Data F10 I2C3_SDA Expander E Part number:  MCP23017-E/ML Expander E diagram Expander E pins description Pin Port Type User-space name Description 1 GPB4 GPI gpiochip5 12 Digital input 4 (DIO circuit) 2 GPB5 GPI gpiochip5 13 Digital input 5 (DIO circuit) 3 GPB6 GPI gpiochip5 14 Digital input 6 (DIO circuit) 4 GPB7 GPI gpiochip5 15 Digital input 7 (DIO circuit) 5 VDD +3V3 X Power supply 6 VSS GND X Ground 7 NC NC X Not connected 8 SCK GPIO X I2C clock 9 SDA GPIO X I2C data 10 NC NC X Not connected 11 A0 +3V3 X Address bit 0 12 A1 +3V3 X Address bit 1 13 A2 GND X Address bit 2 14 RESET/ EXP1_NRST X Reset 15 INTB GPIO_EXP_INT X Interrupt B 16 INTA GPIO_EXP_INT X Interrupt A 17 GPA0 GPO gpiochip5 0 Termination RS485_4 ON / OFF 18 GPA1 GPO gpiochip5 1 Termination RS485_3 ON / OFF 19 GPA2 GPO gpiochip5 2 Termination RS485_2 ON / OFF 20 GPA3 GPO gpiochip5 3 Termination RS485_1 ON / OFF 21 GPA4 NC X Not connected 22 GPA5 NC X Not connected 23 GPA6 GPO gpiochip5 6 Secure chip idle/busy 24 GPA7 GPI gpiochip5 7 Digital input 1 (DIO circuit) 25 GPB0 GPO gpiochip5 8 Digital input 2 (DIO circuit) 26 GPB1 GPI gpiochip5 9 SD detect 27 GPB2 GPI gpiochip5 10 VIN level error 28 GPB3 GPI gpiochip5 11 Digital input 3 (DIO circuit) I2C3 Device name: /dev/i2c-2 Signal Processor pin Default function Clock E10 I2C3_SCL Data F10 I2C3_SDA Expander F Part number:  SC16IS752IBS Expander F diagram Expander F pins description Pin Type Usage User-space name Description 1 RXA(I) RS485_UART4_RX X RS485 UART4 RX 2 RESET/ RS485_NRST X Reset 3 XTAL1(I) TXCO_OUT X Oscillator output 4 XTAL2(O) NC X Not connected 5 VDD +3V3 X Power supply 6 I2C / SPI/ GND X Ground 7 CS/ / A0 SPI2_CS2 X SPI chip select 8 SI / A1 SPI2_MOSI X SPI master out slave in 9 SO SPI2_MISO X SPI master in slave out 10 SCL / SCLK SPI2_SCLK X SPI clock 11 SDA / VSS GND X Ground 12 VSS GND X Ground 14 IRQ/ RS485_INT X RS485 interrupt 15 CTSB/ NC X Not connected 16 RTSB/ RS485_UART3_RTS X RS485 UART3 RTS 17 GPIO0 / DSRB/ NC X Not connected 18 GPIO1 / DTRB/ NC X Not connected 19 GPIO2 / CDB/ NC X Not connected 20 GPIO3 / RIB/ NC X Not connected 22 TXB(O) RS485_UART3_TX X RS485 UART3 TX 23 RXB(I) RS485_UART3_RX X RS485 UART3 RX 24 GPIO4 / DSRA/ NC X Not connected 25 GPIO5 / DTRA/ NC X Not connected 26 GPIO6 / CDA/ NC X Not connected 27 GPIO7 / RIA/ NC X Not connected 30 RTSA/ RS485_UART4_RTS X RS485 UART4 RTS 31 CTSA/ NC X Not connected 32 TXA(O) RS485_UART4_TX X RS485 UART4 TX SPI2 Signal Processor pin Default function Chip select 0 A6 SPI2_CS0 Chip select 1 AF12 SPI2_CS1 Chip select 2 AB19 SPI2_CS2 Master in slave out A8 SPI2_MISO Clock E6 SPI2_SCLK Master out slave in B8 SPI2_MOSI Connectors Designations Tiger City IMX Industrial Computer with Linux OS Principle of designating connector pins Each pin designation is composed of 2 parts. Part 1 Choose a letter stating the type and purpose of the connector, chosen individually with ease of use by the user in mind. General connectors D - digital input pin H - digital input/output pin U - universal input/output pin G - ground potential  RS485 A - A pin of the connector B - B pin of the connector RS232 T - Tx pin of the connector R - Rx pin of the connector 1-Wire 5V - +5 V voltage 1W - 1-Wire data Part 2 Choose a digit representing the pin on the connector. In case of more than 10 pins on the connectors, letters should be used. Connector designations for IMX8 Eagle designation Documentation designation Digital inputs connectors 1 G 2 D1 3 D2 4 D3 5 D4 6 D5 Digital inputs/outputs connectors 1 H1 2 H2 3 H3 4 G 5 H4 6 H5 7 H6 8 H7 Universal inputs/outputs connector 1 U1 2 U2 3 G 4 U3 5 U4 RS485 1/2 connectors 1 A1 2 B1 3 G 4 A2 5 B2 RS485 3/4 connectors 1 A3 2 B3 3 G 4 A4 5 B4 RS232 1/2 & 1-Wire connectors 1 G 2 T1 3 R1 4 T2 5 R2 6 1W 7 5V 8 G