FAQs for reTerminal Usage
This document contains all the frequently asked questions related to reTerminal. This will be very helpful if you are suffering from any issues when using the reTerminal.
Q1: How can I update the STM32 firmware for reTerminal LCDโ
Note: If your reTerminal is manufactured after 26/09/2021, the STM32 comes with V1.8 firmware pre-installed.
It is very important to make sure that you have the latest firmware flashed on to the STM32G030 chip on the reTerminal. STM32G030 is responsible to drive the LCD on the reTerminal. Updating the STM32 chip to the latest version will be helpful to solve most of the issues that you face with the reTerminal LCD.
There are 2 methods of flashing the STM32 chip.
- Method 1: Directly connect to STM32 chip using the CM4 on the reTerminal and flash the firmware
- Method 2: Physically connect the STM32 chip pins to the 40-Pin reTerminal GPIO using jumper wires and then use OpenOCD to flash the firmware
Method 1 works if you have the new version (v1.7 or higher) of the STM32 firmware on the reTerminal and on the other hand, method 2 is only needed if you have the old version (lower than v1.7) of the STM32 firmware on the board.
Decide Which Flashing Method to Useโ
Now let's go through the following steps to identify which version of the board we have so that we can choose the appropriate flashing method.
- Step 1. Enter terminal window of reTerminal and type the following to open the configuration file
sudo nano /boot/config.txt
- Step 2. At the very bottom of this file, comment out the line which says dtoverlay=reTerminal
#dtoverlay=reTerminal
Note: This will unload all the reTerminal drivers. So when you turn on the reTerminal next time, none of the drivers will be loaded.
- Step 3. Reboot reTerminal
sudo reboot
- Step 4. Make STM32 enter boot mode through i2c-tools
i2ctransfer -y 1 w2@0x45 0x9b 0x01
- Step 5. List the connected I2C devices
i2cdetect -y 1
If you can see the I2C address 0x56 as the table below, you have the new version (v1.7 or higher) of the STM32 firmware on the board.
However, if you can see the I2C address 0x45 as the table below, you have the old version (lower than v1.7) of the STM32 firmware on the board
- Step 6. Open the configuration file that we used before
sudo nano /boot/config.txt
- Step 7. At the very bottom of this file, uncomment the line which says dtoverlay=reTerminal to load the drivers again
dtoverlay=reTerminal
- Step 8. Power off reTerminal
sudo poweroff
Note: If you are already running STM32 v1.8 firmware, once you enter boot mode through i2c-tools, the only way to come out of boot mode is to flash the STM32 firmware.
Connect to STM32 using CM4 and flash the firmwareโ
If you have the new version (v1.7 or higher) of the STM32 firmware on the board, please follow this method.
- Step 1. Enter terminal window of reTerminal and type the following to open the configuration file
sudo nano /boot/config.txt
- Step 2. At the very bottom of this file, comment out the line which says dtoverlay=reTerminal
#dtoverlay=reTerminal
- Step 3. Reboot reTerminal
sudo reboot
- Step 4. Make a new directory inside reTerminal
mkdir STM32
- Step 5. Visit this link and download stm32flash file and the STM32G030F6_R2.bin file from the latest release version.
Note: You can click on them to start downloading
- Step 6. Open command prompt on PC and navigate to the location of the downloaded files before
cd C:\Users\user\Downloads
- Step 7. Transfer the files to the STM32 directory on the reTerminal we created before
scp -r .\stm32flash .\STM32G030F6_R2.bin pi@192.168.x.xx:\home\pi\STM32
Note: pi is the username and 192.168.x.xx is the IP address of reTerminal. You can replace this with hostname of reTerminal as well.
- Step 8. Inside the terminal window of reTerminal, enter the STM32 directory
cd STM32
Then you will see the files that we copied earlier
- Step 9. Make the flash tool executable
chmod +x stm32flash
- Step 10. Make STM32 enter boot mode through i2c-tools
i2ctransfer -y 1 w2@0x45 0x9b 0x01
- Step 11. Erase the flash in the STM32 chip using stm32flash tool
./stm32flash -a 0x56 -o /dev/i2c-1
- Step 12. Flash the firmware to STM32 using stm32flash tool
./stm32flash -a 0x56 -w STM32G030F6_R2.bin -v -g 0x0 /dev/i2c-1
Note: STM32G030F6_R2.bin is the file name of the new firmware
- Step 13. Modify the OPTR register as follows
i2ctransfer -y 1 w2@0x45 0x9b 0x00
- Step 14. Open the configuration file that we used before
sudo nano /boot/config.txt
- Step 15. At the very bottom of this file, uncomment the line which says dtoverlay=reTerminal
dtoverlay=reTerminal
- Step 16. Reboot reTerminal
sudo reboot
Now you have successfully flashed the firmware to STM32!
Connect to STM32 using jumper wires and OpenOCDโ
If you have the old version (lower than v1.7) of the STM32 firmware on the board, please follow this method.
- Step 1. Enter terminal window of reTerminal and type the following to update the packages list
sudo apt-get update
- Step 2. Install the following packages
sudo apt-get install git autoconf libtool make pkg-config libusb-1.0-0 libusb-1.0-0-dev
- Step 3. Clone the following repo and navigate to it
git clone http://openocd.zylin.com/openocd
cd openocd
- Step 4. Visit this link and download the STM32G030F6_R2.bin file from the latest release version.
Note: You can click on it to start downloading
- Step 5. Open command prompt on PC and navigate to the location of the downloaded files before
cd C:\Users\user\Downloads
- Step 6. Transfer the files to the openocd directory on the reTerminal we created before
scp -r .\STM32G030F6_R2.bin pi@192.168.x.xx:\home\pi\openocd
Note: pi is the username and 192.168.x.xx is the IP address of reTerminal. You can replace this with hostname of reTerminal as well.
- Step 7. Come back to terminal window on reterminal and enter the following inside the openocd directory
./bootstrap
- Step 8. Enter the following
./configure --enable-sysfsgpio --enable-bcm2835gpio
- Step 9. Compile it
make
- Step 10. Install it
sudo make install
- Step 11. Follow the connection below to connect the pins from STM32 to 40-Pin GPIO
Note: The STM32 pins are located at the back of reTerminal PCBA.
- Step 12. While keeping the connection, enter the following command to flash the firmware to STM32
openocd -f interface/sysfsgpio-raspberrypi.cfg -c "transport select swd" -f target/stm32g0x.cfg -c "program STM32G030F6_R2.bin verify 0x08000000;shutdown"
Note: Normally it takes about 3 seconds to finish flashing. So you need to hold the above connection for about 3 seconds until the flashing process is complete
If you see the following log, that means the STM32 firmware is successfully flashed!
- Step 13. Disconect the connections and physically disconnect the power cord directly without poweroff command
Note: If you don't physically unplug the power cord, STM32 firmware will not load successfully
Now you have successfully flashed the firmware to STM32!
Check the installed STM32G030 firmware versionโ
Now let's check the installed STM32 firmware version
- Step 1. Enter terminal window of reTerminal and type the following to open the configuration file
sudo nano /boot/config.txt
- Step 2. At the very bottom of this file, comment out the line which says dtoverlay=reTerminal
#dtoverlay=reTerminal
Step 3. Reboot reTerminal
Step 4. Enter the following inside terminal window of reTerminal to check the STM32 firmware version
i2ctransfer -y 1 w1@0x45 0x97 r2
If the output looks like 0x01 0x07, that means you are using firmware version 1.7
- Step 5. Open the configuration file that we used before
sudo nano /boot/config.txt
- Step 6. At the very bottom of this file, uncomment the line which says dtoverlay=reTerminal
dtoverlay=reTerminal
- Step 7. Reboot reTerminal
sudo reboot
Q2: How can I flash Raspberry Pi OS which is originally shipped with reTerminal?โ
If you have flashed to a different OS and want to switch back to the default Raspberry Pi OS which is shipped with reTerminal, you can follow the steps below
Step 1. Download the Raspberry Pi OS by visiting the links below
Note: reTerminal is originally shipped with 32-bit OS. However, you can download a 64-bit version as well
Step 2. Extract the .zip file
Step 3. Open Raspberry Pi Imager software
- Step 4. Press CTRL + SHIFT + X on the keyboard to open Advanced options window
Here you can set a hostname, enable SSH, set a password, configure wifi, set locale settings and more
- Step 5. Click CHOOSE OS and select Use custom
Step 6. Navigate to the previously extracted image, select it and click open
Step 7. Click CHOOSE STORAGE and select the connected eMMC drive
Step 8. Finally, click WRITE
Q3: How to upgrade Raspberry Pi OS and the installed packagesโ
We will update all the packages and also the Raspberry Pi OS to the latest version
- Step 1. Open a terminal window on the reTerminal and type the following
sudo apt update
sudo apt full-upgrade
- Step 2. Reinstall kernel headers
sudo apt install raspberrypi-kernel-headers
- Step 3. Reboot the reTerminal
sudo reboot
Now your Raspberry Pi OS and all the necessary packages are up to update!
Q4: How can I flash OS if I replace the CM4 with non-eMMC versionโ
If you want to use a Compute Module 4 without eMMC on the reTerminal, then you need to insert a micro-SD and flash the OS of your choice. Follow the steps below according to your operating system.
Step 1. Insert a micro-SD card to the computer using a micro-SD card reader connected to the computer, or by using a built-in card reader on a laptop
Step 2. Download Raspberry Pi Imager software by visiting this link
Note: You can choose to download for either Windows, Mac or Ubuntu
- Step 3. Open Raspberry Pi Imager software
- Step 4. Press CTRL + SHIFT + X on the keyboard to open Advanced options window
Here you can set a hostname, enable SSH, set a password, configure wifi, set locale settings and more
- Step 5. Click CHOOSE OS and select your preferred OS
NOTE: You can select OS such as 64-bit Ubuntu by navigating into Other general purpose OS
Step 6. Click CHOOSE STORAGE and select the connected micro-sd card
Step 7. Finally, click WRITE
Please wait a few minutes until the flashing process is complete.
- Step 8. Eject the micro-SD card from computer and insert it into the reTerminal.
Note: You need to open the shell of the reTerminal to access the micro-sd card slot
Q5: How can I log in to Raspberry Pi OS/ Ubuntu OS or other OS using a USB to serial converterโ
If you have a USB to Serial Converter, you can use the following steps to log in to Raspberry Pi OS
Connect jumper wires from a USB to Serial Converter to the UART pins on the 40-pin GPIO header of the reTerminal as follows
Now let's configure the software on the computer. Please follow according to your operating system
For Windowsโ
Step 1. Connect the USB to Serial Converter to the PC
Step 2. Open Device Manager by typing Device Manager in the windows search box
Step 3. Click on the drop-down arrow from Ports (COM & LPT) and find the name of the connected serial port (ex: COM7)
- Step 4. Download and install Putty by visiting this link
Note: Putty is an SSH and telnet client where you can use it to connect to the reTerminal via SSH. You can skip this step if you already have Putty installed
Step 5. Open Putty to connect the PC to the reTerminal
Step 6. Select Serial under the Connection Type
Step 7. Configure the settings as follows:
- Serial line: COM7 (choose your COM port)
- Speed: 9600
Step 8. Click Open
Step 9. On the Putty window, enter the login details as follows
- Username: pi
- Password: raspberry
- Step 10. If you have sucessfully logged into the Raspberry Pi OS, you will see the following output
For Mac/Linuxโ
Step 1. Connect the USB to Serial Converter to the PC
Step 2. Open a terminal window on Mac/Linux
Step 3. Type the following to update the packages list
sudo apt-get update
- Step 4. Type the following to install minicom
sudo apt-get install minicom
- Step 5. Type the following in the terminal to view the connected serial devices
dmesg | grep tty
Ex:
[ 1562.048241] cdc_acm 1-3:1.0: ttyACM0: USB ACM device
- Step 6. Connect to the serial device by typing the following
minicom -D /dev/ttyACM0 -b 9600
Note: The baud rate is set to 9600
- Step 7. After the hardware connections mentioned above, turn on the power from the wall power socket to power on the reTerminal
Now you have successfully logged into Raspberry Pi OS.
Q6: I cannot wake up the reTerminal LCD after sleepโ
Open a terminal window after connecting through SSH or VNC and enter the following commands
DISPLAY=:0 xset dpms force off
DISPLAY=:0 xset dpms force on
This will reinitialize the LCD on the reTerminal
Q7: How can I boot an OS from USB Flash Driveโ
You can boot an OS from USB Flash Drive by following the steps below. Here we change the boot order to USB Boot > eMMC Boot, which means, if the USB Boot fails, it will boot from eMMC.
Note: You will have to use Ubuntu or MacOS as host PC for this method.
- Step 1. Remove the 4 rubber covers and open the reTerminal back shell unscrewing the 4 screws underneath
- Step 2. Remove the 2 screws to disassemble the heatsink and also the remaining 4 screws to take apart the entire case
- Step 3. Flip down the boot mode switch according to the below diagram
- Step 4. Open a Terminal window inside the Host PC after connecting to reTerminal and type the following to update the packages list
sudo apt update
- Step 5. Install Git by the following command
sudo apt install git
- Step 6. Git might produce an error if the date is not set properly. Type the following to correct this
sudo date MMDDhhmm
NOTE: Where MM is the month, DD is the date, and hh and mm are hours and minutes respectively.
- Step 7. Clone and enter the usbboot tool repository
git clone --depth=1 https://github.com/raspberrypi/usbboot
cd usbboot
- Step 8. Enter the following to install libusb
sudo apt install libusb-1.0-0-dev
- Step 9. Build and install the usbboot tool
make
- Step 10. Open the bootloader configuration file
sudo nano recovery/boot.conf
- Step 11. Change the BOOT_ORDER field to the following
BOOT_ORDER=0xf15
Note: Here if USB Boot fails, it switches to eMMC boot
- Step 12. Run the following to update the EEPROM image
cd recovery
./update-pieeprom.sh
The pieeprom.bin file is now ready to be flashed to the Compute Module 4
- Step 13. Navigate back to the usbboot directory
cd ..
- Step 14. Run the usbboot tool to flash the bootloader EEPROM
sudo ./rpiboot -d recovery
- Step 15. Connect reTerminal to the PC via USB Type-C cable
Now it will take a few seconds to transfer the necessary files to the reTerminal.
Step 16. Turn off reTerminal, flip the Boot Mode switch back to the original position and assemble the reTerminal shell
Step 17. Connect a bootable USB Flash Drive with a suitable OS inside, connect to one of the USB Ports on the reTerminal and turn on reTerminal
Now you will see reTerminal booting from the connected USB Drive
Q8: Why there is black glue around the chips on the CM4?โ
We have specially applied epoxy resin underfill adhesive (which looks like black glue) around the chips on the CM4 to make sure the ICs are protected well. This also makes the whole CM4 more reliable.
Q9: Why does buzzer, LEDs and buttons do not work after installing the reTerminal drivers?โ
reTerminal comes equipped with 2 versions for the I/O Expansion chip. Old version with MCP23008 and new version with PCA9554. If you installed reTerminal drivers manually, please check the following.
First of all check whether which chip is installed on your reTerminal.
- Open terminal window
- i2cdetect -y 1
If you see 0x20 I2C address, the reTerminal is equipped with MCP23008 chip
If you see 0x38 I2C address, the reTerminal is equipped with PCA9554 chip
For reTerminal with MCP23008 chip, you need to do the following.
- sudo nano /boot/config.txt
- Add "dtoverlay=reTerminal,addr=0x20,mcp23008" at the end of the file
- Ctrl + x > y > ENTER, to save and close the file
- sudo reboot
For the reTerminal with the latest PCA9554 chip, you don't have to do any changes.
Q10: How can I install Ubuntu on reTerminal?โ
- Step 1. Flash Ubuntu Server 21.10 to reTerminal eMMC storage
Note: Refer to flashing instructions here. After opening Raspberry Pi Imager, navigate to CHOOSE OS > Use custom and select the above image to flash
- Step 2. SSH into reTerminal and run the following commands one after the other. Make sure to use ubuntu as the username and ubuntu as the password
wget https://files.seeedstudio.com/wiki/ReTerminal/ubuntu/script1.sh
wget https://files.seeedstudio.com/wiki/ReTerminal/ubuntu/script2.1.sh
chmod +x script1.sh script2.1.sh
sudo ./script1.sh
sudo reboot
sudo ./script2.1.sh
sudo reboot
- Step 3. Now, reTerminal will boot into Ubuntu Desktop, but in wrong orientation
- Step 4. Click the power icon on top right corner and click Settings
- Step 5. Select Displays and choose Portrait Left under Orientation and click Apply
Finally you will see the Ubuntu Desktop in proper orientation!
Q11: The screen orientation is incorrect after installing Raspberry Pi OS Bullseyeโ
Step 1. After flashing Raspberry Pi OS Bullseye to reTerminal eMMC, follow this guide to install the necessary drivers
Step 2. Create a new file named monitors.xml under .config directory
sudo vi ~/.config/monitors.xml
- Step 3. Copy the following content into the above file to explicitly set the LCD display (DSI-1) and save the file by typing :wq after pressing ESC
<monitors version="2">
<configuration>
<logicalmonitor>
<x>0</x>
<y>0</y>
<primary>yes</primary>
<monitor>
<monitorspec>
<connector>DSI-1</connector>
<vendor>unknown</vendor>
<product>unknown</product>
<serial>unknown</serial>
</monitorspec>
<mode>
<width>720</width>
<height>1280</height>
<rate>60.000</rate>
</mode>
</monitor>
<transform>
<rotation>right</rotation>
</transform>
</logicalmonitor>
</configuration>
</monitors>
- Step 4. Open /boot/config.txt
sudo vi /boot/config.txt
- Step 5. Add the following into the file
dtoverlay=reTerminal,tp_rotate=1
- Step 6. Reboot reTerminal
sudo reboot
Now the screen will be displayed in the correct orientation!
Q12: LEDs and Buzzer do not work after installing reTerminal driversโ
This issue will not last long. We will completely solve this issue later from reTerminal drivers itself
- Step 1. Open /boot/config.txt
sudo vi /boot/config.txt
- Step 2. Comment the following line and save the file by typing :wq after pressing ESC
#dtoverlay=reTerminal-bridge
- Step 3. Reboot reTerminal
sudo reboot
Now the LEDs and Buzzer will work as normal.
Q13: How to check if the Encryption Chip is ATECC608A-SSHDA-B or ATECC608A-TNGTLSS-Gโ
| Released Date | Encryption Chip IC Version |
|---|---|
| Before 09/03/2021 | ATECC608A-SSHDA-B |
| Sept 2021 - January 2022 | ATECC608A-SSHDA-B or ATECC608A-TNGTLSS-G |
| After 02/01/2022 | ATECC608A-TNGTLSS-G |
To check which Encryption chip by type i2cdetect -y 3 command in Terminal, If you see 0x35 in the output table then the reTerminal is equipped with ATECC608A-TNGTLSS-G chip, otherwise it is equipped with ATECC608A-SSHDA-B.
Resourcesโ
[PDF] reTerminal Schematics
[ZIP] reTerminal Schematics
[Web Page] Raspberry Pi Official Documentation
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