🚀 Project Overview

This repository contains subprojects to upgrade the Juwei17 mount with enhanced hardware, software, and mechanics. The goal is to provide a modern, feature-rich, and user-friendly experience for astronomy enthusiasts.

---

🧑‍🔧 Skills Needed

• Project is very DIY oriented
• PCB is very dense and it is recommended to manufacture it via some service (JLCPCB or similar)
• Some soldering (hall sensors, BME280, switch, connector crimping)

---

✨ Upgrade Features

• Larger on/off switch
• Homing
• GPS
• Weather sensors
• Fast slewing possible
• Support for TMC SPI or UART modules
  (TMC2209, TMC2130, TMC5160, etc.)
• USB-C connector
• Programming button (no ST-Link needed)
• Loader application (semi-automatic programming for OnStep and SWS)

---

🧩 Hardware Features

• Minimized PCB size
• Support for Home and Limit switches
• OnWire interface
• GPS interface
• STM32F446 as main processor
• Power switch not needed:
  • Mount will start without switch connected
  • No high current goes through switch itself
  • When switch is closed, mount is off

---

💾 Software Features

• Based on OnStepX (preconfigured, just upload)
• Added STM32 RTC support
• Modified Weather:
  • Due to excessive BME self-heating
  • Temperature from DS1820
  • Humidity and pressure from BME280
• TLS fallback (STM32 → GPS)
• PlatformIO is used for OnStepX - My preferred IDE
• Arduino for SWS - due to specific version of ESP toolchain needed

---

🏗️ Mechanics

• CAD files
• STL files for 3D printing new covers

---

📦 Required Components

• New hardware - data on this github repo
• 2x TMC Drivers - you can reuse TMC2209 from your original main board
  • TMC2209 UART - link
  • TMC2130 SPI - link
  • TMC5160 SPI - link
• Beitian BK-280 GPS module - link
• BME280 module - link
• DS1820 - link
• 2× 3144 hall sensors for homing functionality link
• 16mm antivandal switch - 16mm, 12-24V, latching - link
• Wires, connectors, hot glue, etc.
• Crimping pliers (Iwiss IWS-2820M)
• Magnetic rings:
  • Magnets 20×5×2mm link ⚠️ Warning: Large deviation in sizes experienced!
• Screws M2×6 Voron style self-tapping screws - link
• 4x M3x16, 4x M3x10 countersunk
• optional 3144 hall sensor module for test link
  • 5V power
  • It can help you to check polarity and sensitivity for you DIY magnet rings

---

🛠️ Building Tips

• Use hot glue to fix hall sensors and wires
• Mind the hall sensor "polarity" and magnets orientation in rings - good to check with dry run before mounting everything together

---

📁 Folder Description

• CAD: SolidEdge models (*.par files)
• HW: KiCad files (design and schematic PDF)
• Images: Build images
• OnstepEspLoader: Python app to support you through flashing process
• OnStepX: OnStep code (PlatformIO and VSCode)
• SmartWebServer: ESP8266 code (built in Arduino due to specific Espressif version)
• STLs: Files for 3D printing

---

📝 ToDo

• PEC

---

🖼️ Photo Gallery

---

🛠️ Assembly Instructions

1. Print the required parts.
2. Prepare magnets for the magnet rings:
   • Ensure all magnets are oriented in the same direction.
   • Take care to prevent magnets from snapping together unexpectedly.
   • Test magnet polarity using a 3144 module or a bare sensor.
3. Insert magnets into the rings.
   • Fill roughly 90-180degrees
4. Secure magnets with a thin layer of epoxy.
   • 5min epoxy is ideal
5. Assemble the front cover using small screws.
   • Put together PCB_holder and front_panel
6. Install hall sensors and wiring into the new cover.
   • Insert hall sensor with right orientation (double check)
   • Fix them in place with hotglue
7. Mount the new 16mm switch and do wiring.
   • We use NO contact for mount ON, NC contact for mount OFF
   • Switch backlight is connected to mainboard
8. Prepare and install wiring for the GPS and BME280 modules.
   • Solder longer wires and cut them later to perfect length for BME280
   • For GPS just cut the wire to perfect length
   • Install modules in cavities
   • Fix GPS with GPS_holder and small screws
9. Install the DS1820 sensor in the second cover.
   • Pressfit the sensor in place
   • Cut wires to size
10. Secure all wires with hot glue.
    • Aim is to not have wires getting pinched during cover installation
11. Trim wires to length and crimp connectors.
12. Plug in jumper for UART/SPI TMC
13. Insert TMC modules
14. PCB installation
    • Reuse brass standoff - insert them into holes in front cover
    • Attach the PCB to these standoffs
15. Connect all components together.
    • Install back cover
    • Plug in all connectors
    • Install front cover
    • Screw in four screws for the PCB from the bottom of the mount
16. Assembly complete!

---

💻 Firmware Upload

1. Power off the device.
2. Press and hold the button next to the power connector.
3. Power on the device.
4. Observe the LEDs:
   • OnStep status LED will be off.
   • WiFi LED will blink if firmware is present; if the ESP is empty, both LEDs will be off.
5. Start the OnstepEspLoader Python app.
6. Select the correct TMC module type.
7. Choose homing
8. Click "Check STM32":
   • The bootloader should respond.
   • If it fails, click again.
9. Click "Upload STM32":
   • Firmware upload will start.
10. Wait for the OnStep status LED:
    • It should turn on after some time.
    • The first boot may take longer as EEPROM is being formatted.
11. Click "Check OnStep":
    • It should respond with name and version.
12. Switch to SWS mode:
    • OnStep enters transparent mode and is ready to upload ESP firmware.
13. Click "Upload ESP":
    • Firmware for the webserver will be uploaded to the ESP.
14. Finish:
    • A soft reset will occur after some time, or you can power cycle the device manually.

---

⚙️ Default Firmware Configuration

Default firmware configuration expects:

• BME280, DS1820 - if initialization fails, there will be no weather information on webserver
• TMC2209, TMC5160 or TMC2130 - according to selected firmware during programming
• Correct polarity of HAL sensors for homing - if not fulfilled, homing will not work correctly
• Motor current is set to 1.0A for RUN and 1.3A for GOTO
• Homing sense is HIGH

---

🏗️ Build Your Own OnStepX

• If you use OnStepX from Howard Dutton - there will be no support for STM32 RTC (time and date will not be stored) and weather service will provide false temperatures from BME280 (self-heating)
• This could be potentially merged into main branch (I know that STM32 RTC was not planned - there are no official boards ready for this, weather fix is open)
• For my Juwei17 board use the OnStepX from this repository
• Change configuration as needed
• For upload use Serial Bootloader - depending on your IDE (Arduino, PlatformIO) how to do it
• There are three pads on the bottom of the PCB to connect to ST-Link - you need to solder wires or a connector with 2mm pitch
• If you want to use OnstepEspLoader just browse for your STM32 firmware binary
• Binary file pattern:

Firmware Name	TMC Module	Homing
firmware_5160_wH	TMC5160	With Homing
firmware_5160_woH	TMC5160	Without Homing
firmware_2130_wH	TMC2130	With Homing
firmware_2130_woH	TMC2130	Without Homing
firmware_2209_wH	TMC2209	With Homing
firmware_2209_woH	TMC2209	Without Homing