Scales

Recommended Hardware

The hardware requirements are divided into two categories - components for an individual production line that will get a scale and setup hardware for initial configuration.

Hardware for Each Line Running a Scale

The following components are required for each production area where a scale will be deployed:

Setup Hardware

The following components are needed for initial configuration and setup of the Raspberry Pi units:

Support for Other Scales

Essembi can support other scale models in addition to the OHAUS Courier 5000. Connect with an Essembi team member if you have questions about a specific model.

Installation Guide for Scales

Install Pi Case

The top of the case has pillars for transferring heat to the case from the chips, such that the case works like a heat sink.

Thermal Paste Application: Thermal paste should be placed above and below the copper heatsink, but not at all on the thermal pads.

1. Peel off stickers on both ends of the thermal pads. Apply the appropriately sized pads to the three chips specified (all three are black).
2. Apply thermal paste to the top of the processor. Not so much that it will spill out when pressed down.
3. Apply the copper heatsink on the processor. Put a little bit more thermal paste on top.
4. Install the case screws.

Note: Be aware of the USB 3 ports vs the slower USB 2 ports.

Flash the Micro SD Card

Prerequisites

• Download and install Raspberry Pi Imager if it is not already installed
• Download and unzip the latest essembi-scale-pi.img file. The naming convention is essembi-scale-pi-YYYY-MM-DD.img.zip

Flashing Steps

1. Insert a blank Micro-SD card. The card should have come with a micro to full-sized SD adapter.
2. Verify the card is visible in "This PC"
3. Run Raspberry Pi Imager
4. Configure the First Screen:

• Device: Raspberry Pi 4
• OS: Choose "Use Custom" → Select the extracted .img file from the zip above
• Storage: The SDXC card / drive
• Warning: Be VERY careful not to accidentally select your computer hard drive. Should be hidden by default, but be sure of what you are doing.

Edit Settings - General

• Uncheck "set hostname"
• Set user / password
• Set Locale to their time zone

Edit Settings - Services

• Check "Enable SSH"
• Set "Use Password Authentication" as the method
• Save the settings

Complete the Flashing Process

1. When returned to the "would you like to apply" prompt, hit "Yes"
2. When the next prompt appears, click "Yes" again
3. DO NOT REMOVE THE SD CARD IN PROCESS
4. The writer will go through writing and verification steps which take 2-3 minutes
5. When the completion prompt appears, click "Continue", after which it is safe to remove the SD card

When the SD card is written, you should be able to plug it into a Pi and fire it up. The first time you boot it, it may reboot once or twice.

Note: Raspberry Pi boots based on newly receiving power. If you shut it down, simply unplug and plug back in to boot it.

Connect the Scale & Pi

1. Plug in the USB hub into the power
2. Plug the scale into the hub and turn on its port
3. Plug the hub into the Pi
4. Plug the Pi's USB-C power supply in

Program the Scale

The only setting you should have to change on the scale should be to set it in Mettler-Toledo Continuous mode. The other settings that we care about should all be the defaults, but they should be checked if the scale is not working:

• Units: Lbs
• Baud Rate: 9600
• Parity: 8/None
• Stop Bits: 1
• Mode: Weight

Navigating the Scale Menu

• Hold "Menu" to enter the menu
• Hit "No" to go to the next option
• Hit "Yes" to select the current option, go back to the parent menu, and go to the next option in the parent menu
• Hit "Exit" to end the menu

Setting Mettler-Toledo Continuous Mode

To set the mode to Mettler-Toledo Continuous, follow this menu path:

1. Menu
2. Print
3. Assign
4. Mt.CO

With Mt.CO selected, hit "Yes", then "Exit".