Geetech A30T
Contributed by @ImChrono
Max filament units: 7
MCU Name: 3ms
BOM
| Name | Price | Quantity | Link | Notes |
|---|---|---|---|---|
| Geetech A30T | $34.99 | 1 | Geetech | |
| Duponts | $9.99 | 1 | Amazon | These wires are only sufficient to run steppers, not heaters |
| 24V PSU | $7.39 | 1 | Amazon | This PSU is only sufficient to run steppers, not heaters |
Firmware
To flash Klipper firmware to the A30T, run the following command and see the following screenshot:
Next, connect the BOOT0 jumper on the A30T and run:
Wiring
Route the wires from the NEMA17's to the controller board. Follow this table to determine which port to plug the motors into:
| Filament Unit # | Motor Port |
|---|---|
| 0 | X |
| 1 | Y |
| 2 | Z0 |
| 3 | Z1 |
| 4 | E1 |
| 5 | E2 |
| 6 | E3 |
Now, grab your 12V PSU and two M-M duponts, one red and one black (M-M means that there is metal coming out of both ends of the cable). Plug the PSU into the wall, but don't plug the screw terminals into the PSU (the screw terminals have green)
- Plug two red wires into the positive terminal of the screw terminals
-
Plug two black wires into the negative terminal of the screw terminals
Danger
These dupont cables are too thin to run much more than the stepper motors. If you run a heater or other power-intensive device off of the motherboard, the duponts and/or PSU can melt/catch fire. To reduce the risk of this, you can double up on the duponts or get thicker wires.
-
Route the four wires inside closest to your chosen input
- Using the markings on the board, plug the two red wires into the positive terminal on the motherboard
- Using the markings on the board, plug the two black wires into the negative terminal on the motherboard
-
Verify all connections
Warning
If the wires are plugged into the wrong place, or swapped polarities, your motherboard, Stepper motors, and/or PSU can be badly damaged.
-
Plug the PSU screw terminals into the PSU wire
If the motherboard lights up, you wired it correctly!
Finally, plug the motherboard into your Klipper host with the cable that came with it.
UART Conversion
⚠️ Attention: Proceed with Caution! ⚠️
This modification involves delicate hardware changes that require precision and attention to detail. Mistakes in wiring or soldering can permanently damage your GTM32_103_V1 board.
- Double-check connections before applying power.
- Use proper tools and follow best practices for soldering.
- If you are not confident in your skills, seek assistance from an experienced individual or professional.
You proceed at your own risk.
Overview
This guide details the process of modifying the GTM32_103_V1 3D printer controller board to enable UART capabilities. The GTM32_103_V1 board features 7 TMC2208 drivers operating in standalone mode by default. This modification involves removing the SD card slot and repurposing its pinouts for UART communication.
Features of the Modification
- UART Capability: Enables communication with TMC2208 drivers via UART repurposing the SDCard slot
Hardware Changes
Components Modified
- SD Card Slot: Removed entirely to free up pinouts for UART.
- Repurposed Pins: SD card slot pins are reassigned as per the following table:
| TCM2208 Driver | SD Card Pin | STM32 Pin |
|---|---|---|
| Motor0 | 9 | PC7 |
| Motor1 | 8 | PC9 |
| Motor2 | 7 | PC8 |
| Motor3 | 5 | PC12 |
| Motor4 | 3 | PD2 |
| Motor5 | 2 | PC11 |
| Motor6 | 1 | PC10 |
Procedure
- Remove Pull down resistor from each driver:
- Desolder the SMD 1kΩ resistor carefully to avoid damaging the surrounding components.
| TMCDriver | PCB Code |
|---|---|
| Motor0 | R53 |
| Motor1 | R57 |
| Motor2 | R62 |
| Motor3 | R120 |
| Motor4 | R71 |
| Motor5 | R95 |
| Motor6 | R105 |
- Remove the SD Card Slot:
- Desolder the SD card slot carefully to avoid damaging the surrounding components.
- Repurpose the Pinouts:
- Rewire the SD card pins according to the table above.
- Connect each pin to its corresponding UART connection for the TMC2208 drivers.
Testing and Validation
After completing the hardware changes: 1. Connect the board to your 3D printer and power it on. 2. Use your firmware to verify UART communication with each TMC2208 driver. 3. Check for successful responses from the drivers using a terminal or debugging tool.
Photos
Add your photos here to demonstrate the modification process and results:
- Close-up of the TMC driver
-Close-up of the TMC driver with resistor removed (solder the uart pint to the red signed pin)
-
Close-up of the SD card:
-
Rewired pins with labels.
UART Configuration
When configuring this board with Happy Hare firmware, be sure to use UART-mmu.cfg and UART-mmu_hardware.cfg (renaming to mmu.cfg and mmu_hardware.cfg respectively).