Monolith v2#

Overview#

Monolith is a wireless data logger platform with logger hardware (a.k.a. TMA-1) and web-based Control Hub.

The project's inspiration was to help students (me 3 years ago) participating in Formula Student and Baja easily collect data from their cars, but it can be used in any other applications, or just as an ESP32-S3 development board.

This is an open-(source & hardware) project, licensed under the 🍺Beerware License for all non-commercial use. You can find more details on the GitHub.

Features#

📡 Full wireless support

• Real-time telemetry
• Download recorded data
• Transmit User Events
• Transmit CAN messages
• Configure the device (e.g., CAN bit rate)

📀 10 Hz data rate across various signals

• 1x CAN 2.0(A/B)
• 1x External GPS
• 1x Internal 6-axis accelerometer & gyroscope
• 4x Digital input channels
• 6x Analog input channels
• 1x Power supply voltage sensor
• 1x Chip temperature sensor

💡 Customizable web-based data analysis tool

All wireless features require a Wi-Fi connection to the Internet.

Q. But where to get it on the car?
A. Bring a phone with Wi-Fi hotspot on board! It will also make you available to blame the driver by calling them while driving.

Preview#

Compare with v1#

• Size and build cost reduced to about 1/3.
• Better performance and telemetry stability.
• Wireless data download & configuration.
• Remote user event & CAN message transmit.

Data Viewer Demo#

Do It Yourself!#

Monolith is an open-hardware project. It is highly recommended to build the TMA-1 PCB yourself.

KiCAD schematic and layout are available at device/hardware.

Build TMA-1 PCB#

1. Download and unzip monolith-{version}.zip from the Release.
2. Go to JLCPCB and upload pcb/gerbers/GERBER-monolith.zip.
3. Turn on the PCB Assembly toggle switch at the bottom.
   • Select 2D barcode with 5*5mm, Specify Position option for Mark on PCB.
   • No need to adjust any other options. Maybe choose a color you prefer?
     Please just keep in mind that black is the best color ever for the TMA-1 and all other PCBs around the Earth.
4. Upload BOM-monolith.csv and CPL-monolith.csv.
5. Place an order and enjoy some beer until the shipment arrives.
6. Solder 8x Molex 5569-04A2(39300040) connectors to the PCB.
7. Insert a CR1220 battery and an SD card.
8. goto 'Upload Firmware';

Upload Firmware#

1. Prepare a 3.3V UART to USB converter.
   • ⚠️ The converter MUST have both DTR and RTS in addition to RX and TX.
   • ⚠️ Do NOT use a converter with 5V output unless it has a 3.3V voltage selector.
2. Solder a 2x3 2.54mm pin header to the board's UART connector.
3. Connect each pin of the Monolith PCB with the following pinout:
   • 3V3, GND, DTR, RTS: corresponding pins on the converter.
   • RX, TX: cross-connect with the converter (RX ↔ TX).
4. Download and unzip esptool from here.
5. Download and unzip monolith-{version}.zip from the Release.
6. Copy the esptool binary into the unzipped firmware/ directory.
7. Open a command prompt, cd to the firmware/ directory and run:
   ./esptool --chip esp32s3 -b 460800 --before default-reset --after hard-reset write-flash "@flash_args"

Prepare Server#

The TMA-1 and the Control Hub need an MQTT server (broker) to communicate.

For your sake, there is a free default server v2.monolith.luftaquila.io.

To use the default server, send an email to mail@luftaquila.io with your school name, desired channel name and channel key. Please note that the default server may become unavailable at any time for any reason.

sudo apt install -y mosquitto
git clone https://github.com/luftaquila/monolith.git

cd monolith/web
npm install
npm run build

cd ../server/config
# set your channel key as the password
mosquitto_passwd -c mosquitto.passwd <YOUR_CHANNEL_NAME>

cd ..
cp .env.example .env
vi .env # set `ACME_EMAIL` and `DOMAIN_NAME` to your own

sudo docker compose up -d

Usage#

Device (TMA-1)#

As mentioned in the DIY section above, all 8x connectors on the PCB are Molex 5569-04A2(39300040). The mating part is Molex 5557-04R(39012040), which uses the Molex 5556T(39000038) as a crimp terminal.

The pinout for each connector is labeled on the PCB. Please remember that the misconnection of the pins may cause PERMANENT damage to the device.

Specifications#

(1) When voltage divide jumper is connected. 1/2 for AIN5, AIN6 and channels with no jumper.

Wi-Fi#

TMA-1 requires a 2.4GHz Wi-Fi connection to provide wireless features such as live telemetry and remote record downloads.

However, the data logging function works without Wi-Fi. To use it offline, remove the SD card and mount it on your computer after driving.

TMA-1 automatically sets its internal clock via SNTP, so you must connect it to the Internet at least once for time synchronization.

Initial Setup#

1. Power up the device.
2. On first boot, it creates its own Wi-Fi access point (AP) named Monolith v2 XXXXXX. Password is monolith.
3. Connect to that AP and open http://192.168.4.1 in your browser.
   
4. Set Wi-Fi SSID and Wi-Fi Password to the phone's Wi-Fi Hotspot that TMA-1 will connect to while driving (the phone that the driver will bring onboard).
5. Set Server Address to your server.
   • The default server v2.monolith.luftaquila.io is available to the approved users only. To apply, send me an email at mail@luftaquila.io with your school name, desired channel name and channel key.
6. Set Device Name and Device Key to match the values you emailed me.
7. Click Save, then click Reboot.

TMA-1 will try to connect to the configured Wi-Fi network after rebooting.

Reset#

To reset the Wi-Fi and server configuration, short the RST jumper on the PCB for 3 seconds and release. This restores Wi-Fi, server, device name/key, and all configuration data to factory defaults.

After reset, proceed to the Initial Setup step above.

Power & CAN#

The PWR/CAN port supplies power to the TMA-1 and provides a CAN connection.

VIN and GND are the power supply pins. The device draws about 0.5W during active operation (40mA @12V).

A PCB jumper labeled CAN 120Ω enables the on-board termination resistor. Set it according to your CAN bus design. There must be 2x 120Ω resistor on the bus, one at each end, resulting in 60Ω between CANH and CANL line.

GPS#

TMA-1 supports an external GPS module for location tracking.

Connect the GPS port to a GPS module with UART support using the following pinout:

• 3V3 and GND to module power
• GPSRX, GPSTX: cross-connect with the module

Currently, only U-BLOX NEO-6M/7M/8M modules are supported. Support for additional modules may be added in the future on demand.

Debug Output#

DEBUG port is inactive and reserved for custom use.

It is intended for outputting the recorded logs to other onboard MCUs (e.g., a cockpit display).

Electrically, it provides a 3.3V 0.5A power rail and two free GPIO lines. It's up to you to customize how you use this connector.

Digital & Analog#

TMA-1 provides 4x digital inputs and 6x analog inputs, with 5x 5V power rails that can supply 2.5A in total.

Digital Inputs#

• Logic LOW: 0 ~ 0.8V
• Logic HIGH: 2.4 ~ 8.5V

It can withstand brief higher voltages, but continuous operation is limited to 8.5V.

Analog Inputs#

Absolute maximum input voltage of the analog channel is 3.6V.

Meanwhile, AIN1 to AIN4 have a selectable 1/2 voltage divider circuit. It is enabled by connecting the jumper in front of the each AIN channel on the PCB. The maximum input voltage is increased to 7.2V if the divider is enabled.

Therefore, sensors with the maximum output voltage of 5V are only applicable when the divider is enabled.

Since AIN5 and AIN6 have no voltage divider, their maximum voltage is fixed at 3.6V.

Control Hub#

Control Hub is at https://v2.monolith.luftaquila.io and you can use it for free any time.

Live Telemetry#

Before using Live Telemetry, set the server information in the Device Configuration tab.

Also, to view the incoming CAN data, you need to set the CAN Decoders in the UI Configuration tab first.

Once the server is configured correctly and the TMA-1 is online, there is nothing else to do here. Everything will work like magic.

Console#

You can send a user event or a CAN message to the device.

• User Events

  • A user event marks some meaningful points that can help with later data review.
  • To send a user event, fill in the event name and click the send button.
  • If the event name is empty, it will be recorded as USREVT.
  • Only ASCII characters up to 16 bytes are allowed.

• CAN message

  • Enter the CAN message ID (11/29 bits) and the data bytes to send.
  • Click the send button. 0x00 will be sent for the empty data byte fields.

Data Viewer#

To review your drive, you need to download the recorded data first. Refer to the Data Downloader section in the Device Configuration tab to download data.

• Click Select and open a *.log file that you've downloaded.
• In the Graph card, toggle the input category button or the signal name of the legend to see the graph.
• Adjust the slider in the GPS card to see the footage of your vehicle.

To view the recorded CAN data, set the CAN Decoders in the UI Configuration tab first.

UI Configuration#

You can adjust the visibility of the cards in the Live Telemetry and the Data Viewer. Also, you can set the input signal's name, unit and value multipliers.

Refresh the page for the changes to take effect.

Import/Export#

Export/import the current UI configuration across devices/browsers.

Display#

Control the visibility of the cards in each view.

Units#

Manage custom units that can be used for analog and CAN data.

Digital#

This section enables you to change the channel name. (e.g., RUINED IF ON instead of DIN1)

Analog#

• Name: The name shown on the graphs.
• Voltage Divider: Turn on if you have a divider jumper connected on your PCB.
• Multiplier: The number multiplied to the measured voltage. Edit it if you have:
  • Another voltage divider circuit for the sensor.
  • A formula to calculate the original physical value.
• Unit: An appropriate unit of the value. Add one at the Units card if you don't have it.

CAN#

Manage CAN message decoders. A decoder extracts useful data from the CAN message bytes.

• Name: The name shown on the graphs.
• CAN Message ID: The message ID that desired data is included.
• Multiplier: The number multiplied to the original value.
• Unit: The data unit that added on the Units card.
• Data Range: The part of the CAN payload that contains the data.
  • The CAN payload has a maximum length of 8 bytes.
    • Byte mode: The possible range is #0 to #7.
    • Bit mode: The possible range is #0 to #63.
    • To select a single byte/bit, set the start and end range to the same value.
• Data Signedness
  • Unsigned: Decode the data as an unsigned value.
  • Signed: Decode the data as a 2's complement value.
• Data Endianness
  • Only available in Byte mode.
  • Defines the endianness of multi-byte data.

Device Configuration#

This section configures the server for the Control Hub and the device peripherals.

The configurations will be automatically loaded if the device is online.

Server#

• Address: The server for the Control Hub.
• Name / Key: Channel name and key.

All values must match the values configured to the device during the Device - Initial Setup sequence.

The server will be automatically connected after you click the save button.

Device#

• SSID / Password: The Wi-Fi network that the device will connect to.
• Timezone: The POSIX timezone string for your location. Use the converter's TZ_INFO value.
  • It is used to determine the log file name's time. Recorded logs use the UTC time, so it won't be affected.
• T. Interval: The interval at which the device transmits telemetry.

Inputs#

Controls whether the digital/analog input channels are logged or not.

CAN#

• Enabled: Whether the CAN bus is logged or not.
• Bit rate: The bus baud rate.
• Filter: The expected message ID (11/29 bits)
• Mask: The filtering rule for each bit of the filter.
  • 0: The corresponding filter bit must match to pass.
  • 1: The corresponding filter bit is ignored (don't care).

Refer to the Acceptance Filter section of the ESP32-S3 API Reference for the detailed explanation of the Filter and Mask. All CAN messages will be accepted by default.

GPS#

• Enabled: Whether the GPS location is logged or not.
• Device: Select the device type. Only UBLOX is currently supported.

Danger Zone#

• Refresh: Loads the device's configuration.
  • All changed configurations require a device restart to be applied.
  • If you refresh before restarting, the previous value will be loaded.
• Restart: Restart the device.
• Reset: Reset the device. Same as shorting the RST jumper on the board.

Data Downloader#

• Load List: Lists all recorded log files except the current boot session.
• Delete All: Deletes all recorded log files except the current boot session.

After loading the file list, click the download button to download a specific file.

Development#

This section is for computer-guys who wants to modify the software on their own.

git clone https://github.com/luftaquila/monolith.git
cd monolith/device/firmware
make build
make run   # build & flash

git clone https://github.com/luftaquila/monolith.git
cd monolith/web
npm install
npm run vite
npm run build