Hardware I/O Usage

Default Console Login Credentials

  • Username: root
  • Password: root

Serial Debug Port

This section applies to MTCDT-xx-210L only.

The micro USB connector on the front of the device behind the removable panel provides a USB serial debug port. The debug port provides access to the bootloader (U-boot) and the Linux system console.

  • Baud rate: 115,200
  • Data: 8 bit
  • Parity: none
  • Stop: 1 bit
  • Flow control: none

If the USB port isn’t recognized on your computer, download and install this driver: https://www.exar.com/content/document.ashx?id=1596

Ethernet

The built-in ethernet port is a 10/100 Mbps interface. Network configuration is defined in
/etc/network/interfaces.

Defaults:

  • IP address: 192.168.2.1
  • Subnet mask: 255.255.255.0

To change the static IP, change the address and netmask fields in /etc/network/interfaces (use vi or nano). To apply changes, either reboot the device or issue: ifdown eth0; ifup eth0.

To enable the DHCP server with default settings, issue: mlinux-dhcpd start. Configure the dhcp server by editing /etc/udhcpd.conf. You can also issue mlinux-dhcpd stop or mlinux-dhcpd restart.

Cellular

Cellular data/Internet access is provided by the PPP software.

To set up an H5 radio cellular data connection using default options:

# Set "APN" to the APN for your cellular provider
$ mlinux-set-apn APN

# Dial the connection (using /etc/ppp/peers/gsm config)
$ pppd call gsm

# Verify ppp0 is up
$ ifconfig ppp0
ppp0      Link encap:Point-to-Point Protocol  
          inet addr:33.140.12.18  P-t-P:33.140.12.18  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:7 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:106 (106.0 B)  TX bytes:145 (145.0 B)

PPP daemon options are configurable in /etc/ppp/options and in peers files: /etc/ppp/peers/gsm

To reset the cellular radio in the case that the radio is unresponsive to AT commands:
$ mts-io-sysfs store radio-reset 0

The radio-query and radio-cmd scripts can be used to communicate with the radio using these soft links to the radio’s USB ports: /dev/modem_at0 and /dev/modem_at1.

LEDs

MTCDT

There are five software-controlled LEDs on the MTCDT hardware:

  • led-status – default: status (solid during boot, flashes while running)
  • led-a  – default: always off
  • led-b  – default: always off
  • led-c – default: always off
  • led-d  – default: always off

MTCAP

  • STATUS – default: blinks when operating system is fully loaded.
  • LORA  – default: lights when LoRa software is active.
  • CELL  – default: lights when there is power to the cellular radio. Cellular models only.
  • WIFI – default: always off Wi-Fi models only.
  • Ethernet Link  – default: always off

MTCDT and MTCAP

LED control using mts-io provides simple on/off functionality and gives the convenience of using the mts-io-sysfs script.

Examples

  • Turn led-a on:
    $ mts-io-sysfs store led-a 1
  • Turn led-a off:
    $ mts-io-sysfs store led-a 0

 

LED control using the linux leds-gpio driver gives advanced functionality in the form of triggers. Options:

  • none: disable trigger (in order to use mts-io)
  • nand-disk: NAND flash activity
  • timer: custom LED flash timing
  • heartbeat: default for led-status
  • default-on: always on
  • mmc0: SD card activity

Examples

  • Show current led-status trigger:
    $ cat /sys/class/leds/led-status/trigger
  • Change led-status to NAND flash activity:
    $ echo "nand-disk" > /sys/class/leds/led-status/trigger

 

USB ports

This section applies to MTCDT-xx-210L only.

Host port

This port is a USB 2.0 high speed port that functions as a host to any USB device, such as a flash drive, printer, etc. Linux driver support is required for any device attached to this port.

Device port

This port functions as a device connected to a host, such as your development PC. The USB gadget set of Linux drivers provides functionality for connected devices.

By default, this port is configured as a USB serial port (g_serial driver) with a serial login console that functions like the debug port.

This port’s functions can be customized as needed. For example, you can have the Conduit show up as a mass storage device on your PC. To change the gadget driver loaded on boot, edit /etc/default/usb-gadget-mode and change the USB_MODE variable. For USB_MODE available options, see /usr/bin/usb-gadget contents. To disable the serial console, edit /etc/inittab and comment out or delete the line starting getty on ttyGS0.

 

Reset button

The reset button on the MTCDT hardware interfaces to the mts-io utility. A reset button handler named reset-handler installs and starts on boot.

Default reset-handler behavior:

  • Short button press (< 5 seconds): perform soft reboot
  • Long button press (>= 5 seconds): reboot and restore default settings

 

mts-io attributes

  • reset: show current state of reset button
    $ mts-io-sysfs show reset
  • reset-monitor: show/set configuration of PID to signal on button press
    $ mts-io-sysfs show reset-monitor
    $ mts-io-sysfs store reset-monitor �500 10 12 1�

    PID=500, send SIGUSR1 (signal 10) on short press, send SIGHUP (signal 1) on extra long press

  • reset-monitor-intervals: show/set the button press durations used by reset-monitor
    $ mts-io-sysfs store reset-monitor-intervals �5 30�

    Short press: < 5 seconds, long press: < 30 seconds, extra long press: >= 30 seconds

  • Reset-handler uses the reset-monitor and reset-monitor-intervals attributes to configure mts-io and then waits for signals generated by a button press.

To customize reset button behavior, provide a custom version of reset-handler or disable it and install your own handler. See /usr/sbin/reset-handler for reference. To disable reset-handler from starting on boot, modify /etc/default/reset-handler and set ENABLED=�no�.

 

Micro-SD Card

This section applies to MTCDT-xx-210L only.

Cards inserted into the micro-SD slot are auto mounted at /media/card using device /dev/mmcblk0p1 (first partition on the device). Linux Ext2/3/4 and MSFAT file systems are supported by default. To change the mounting behavior, see /etc/fstab.

  • By default, mLinux mounts the SD card using the sync mount option. This flushes all writes to the physical card immediately. This can increase write times, but allows the writing application to know that the data is on the card when it is done writing. It also reduces the chances for filesystem corruption if the SD card is removed from the slot without unmounting it.
  • To improve write performance, the SD card may be mounted with the async option instead. The performance cost of the sync mount option varies from card to card. Some cards gain a very large increase in throughput by using async instead of sync when mounting.
  • To use the async mount option, modify the following line in /etc/fstab and remove ‘, sync
    /dev/mmcblk0p1 /media/card auto defaults,sync,noauto 0 0
  • After modification, the line should read:
    /dev/mmcblk0p1 /media/card auto defaults,noauto 0 0

 

Temperature Sensor

The MTCDT hardware includes an on-board TMP102 temperature sensor, which is accessed via the hwmon sysfs interface. Units are in millidegrees Celsius

Read current temperature:

$ cat /sys/class/hwmon/hwmon0/device/temp1_input