The newest version of the Farmduino Express electronics board features an integrated USB hub connected to the Raspberry Pi via two pogo pins. The USB hub is directly connected to the Arduino’s MCU, providing more reliable flashing of the firmware. Also connected to the hub are a built-in Ethernet adapter for users who need a wired connection to their FarmBot, and two USB Type-C ports for the FarmBot camera and future USB accessories.
The new board also features smaller and more DIY friendly 2.54mm pitch receptacles for the solenoid valve, LED strip, and vacuum pump peripherals. And both the vacuum pump and input power receptacles are now 3-pin connections to provide
PE (protected earth) grounding to reduce the likelihood of EMI issues that affected some v1.0 systems.
Last, the new board includes a pulldown resistor to fix an issue that affected E-stop button performance in the v1.0 design.
Not backwards compatible with the Pi Zero W
Because the Farmduino Express v1.1 board uses a different firmware flashing method, it is not backwards compatible with the Raspberry Pi Zero W included in Express v1.0 kits. In order to upgrade the Farmduino, one must also upgrade the Raspberry Pi to model Zero 2 W.
Express v1.1 includes an upgraded Raspberry Pi Zero 2 W computer to provide faster booting and greater overall performance when compared to the Zero W included in Express v1.0 kits.
Not backwards compatible with Farmduino Express v1.0
Because FarmBot OS for the Raspberry Pi Zero 2 W uses a different firmware flashing method, it is not backwards compatible with the Farmduino Express v1.0 included in Express v1.0 kits. In order to upgrade the Raspberry Pi, one must also upgrade the Farmduino.
The vacuum pump now features a circuit board directly soldered onto the back of the motor which performs EMI filtering and reduces the startup current draw of the motor. This circuitry will help reduce WiFi interference caused by the vacuum pump, as well as the potential for the pump to drop the system voltage below acceptable levels when starting up.
Additionally, the vacuum pump cable is now a shielded cable, with the shielding connected via a third quick-connect terminal to the vacuum pump motor’s housing. The shielding is then connected to
PE (protected earth) grounding at the Farmduino.
Thank you Réstep
The EMI filter circuit included on the back of the v1.1 vacuum pump is based on Chris Arntzen’s openly licensed Réstep EMI Filter add-on for older versions of FarmBot’s vacuum pump.
Thank you Chris for lending your expertise in electronics design to the FarmBot community with this fantastic open-source contribution!
All three cable carriers have been reduced in size to
15mm x 20mm internal dimensions. This saves significant weight and reduces friction when moving. With this change comes new, narrower versions of many other parts adding to overall material, weight, and cost reductions in the kit:
- Cross-Slide Plate
- Z-Axis Motor Mount
- 60mm Vertical Motor Housing
- 30mm Vertical Cable Carrier Supports
- 30mm Horizontal Cable Carrier Supports
- 35mm Horizontal Cable Carrier Mount
- 52.5mm Horizontal Cable Carrier Mount
- 30mm Cable Carrier Spacer Block
- Leadscrew Block
- M3 x 16mm Flat Head Screws
- M3 x 30mm Flat Head Screws
- The camera and camera cable are now manufactured with shielded USB 2.0 cable (
28AWG/1p + 24AWG/2c) to reduce interference problems that affected some v1.0 installations.
- The camera cable now features a USB Type-C plug.
- Additional shrinkwrap labels have been added to differentiate the 90-degree connectors at the Y/Z interface.
- The solenoid valve cable, Y vacuum pump cable, and LED strip now feature smaller and more DIY friendly 2.54mm pitch plugs.
Extensive effort was put into reducing the size and weight of the Express v1.1 packaging. All of the parts and pre-assemblies now fit into a single cardboard tray insert, reducing the height of the main carton and the overall shipped weight of the kit by 20%. Importantly, this brought the weight of Express XL kits under the 50lb threshold where an overweight surcharge applies.
Due to low demand, FarmBot Express MAX was cancelled and is no longer supported in the v1.1 documentation.