Montage OBP40

Assembly drawing

Abb.: Montage OBP40 Main Unit

Bill of materials

Pos.	Number	Designation	Material	Source
1	1	Front Case	ABS / ASA	Filamentworld
2	1	Backside Case	ABS / ASA	Filamentworld
3	1	Crow Panel 4.2	FR4	Elecrow
4	1	LiPo-Battery 1	3.7V, 1200mA	Ebay 1
5	1	Magnet Dock	4 Pol.	Aliexpress
6	4	Magnets D5x3	Neodym	Ebay 2
7	1	Velcro D 3 mm	50 X 40 mm	Ebay 3
8	4	M2.5x4	Steel/Nickel

1

LiPo battery: 52 x 43 x 6 mm

Assembly instructions

The housing is assembled according to the assembly instructions in the following order:

1. Print housing parts

   The housing parts can be printed with a standard 3D printer. Use the following settings:

   • 0.4 Mm nozzle

   • Wall thickness 1 mm

   • Wall thickness of the top and bottom: 1 mm

   • Fill level 30%

   • Support enabled

   Hint

   The front panel is designed for two-color printing. The black areas are implemented as 0.2 mm thick inlays. Consult your printer’s documentation for two-color printing instructions. If your printer does not support two-color printing, you can also print the front panel in a single color. Simply use the STL file for this.

2. Unscrew the back and spacers of the Crow Panel 4.2

   

   Fig.: Crow Panel 4.2 Mainboard Top (Elecrow)

3. Insert the Crow Panel 4.2 circuit board into the front cover.

   Insert the circuit board into the front panel, starting from the side with the buttons.

   

4. Glue the magnetic dock to the back panel using hot glue.

   Ensure the magnetic dock is centered and thoroughly coated with hot glue. Make sure no hot glue seeps out. Remove any excess hot glue if necessary.

   

5. Glue magnets into the back panel using hot glue.

   Before inserting the magnets, put a small dab of hot glue into the recess and quickly insert the magnet so that the glue doesn’t set prematurely. Make sure not to use too much hot glue in the recess.

6. Cut the hook and loop tape to 50 x 40 mm and glue it into the recess of the back panel.

   Stick the Velcro strip in place so that it does not protrude at the edges and is completely inside the recess.

   

7. Install the LiPo battery, magnetic dock and voltage divider, and solder the cables.

   Hint

   Soldering the cables requires good soldering skills and high-quality soldering tools, as the connections are very small. Use a temperature-controlled soldering iron with a fine tip and 0.5 mm diameter solder. Flux and copper tape for absorbing excess solder will simplify the process. If you are unsure about doing this yourself, contact a professional for assistance.

   Warning

   Take care not to cause short circuits on the circuit board with other components. Do not solder for too long at the affected points, as you may desolder components or damage traces. Check all solder joints before putting the circuit board back into operation. Use a digital voltmeter to check for short circuits at the solder joints. Keep in mind that soldering work will void the manufacturer’s warranty.

   Solder the cables according to the table and the pictures.

   Soldering point	Aderfarbe	Component
   C5 top	Red, 3.7V	LiPo Battery
   C5 below	Black	LiPo Battery
   C4 links	Rot, 5 V	Magnet Dock
   R2 links	White, D-	Magnet Dock
   U1 Pin 5	Yellow, D+	Magnet Dock
   C4 right	Black	Magnet Dock
   C5 top	Rot	V-splitter
   IO3	Green	V-splitter
   USB-C, GND	Black	V-splitter

   

   Fig.: Solder points for connecting cables

   

   Fig.: Voltage divider for state of charge measurement

   

   Fig.: Solder point for IO3

   

   Fig.: Solder points for USB-C GND

   

   Fig.: Position of the LiPo battery on the circuit board

   Note

   Make sure to insulate the connecting cables on the magnetic dock with 3 mm heat shrink tubing. This will prevent short circuits with the circuit board.

   

8. Place the back panel onto the front panel and connect it with M2.5 screws.

   Use the screws you removed from the back of the Crow Panel 4.2. The holes in the plastic are sized so that you can screw the screws in with a little pressure. The thread will then cut into the plastic on its own.

   Hint

   If you need to re-tighten the screws, first turn them counterclockwise until you feel the threads click into place, and only then tighten them clockwise. This will prevent damage to the threads.

9. Flashing firmware

   The last step involves flashing the firmware. Follow the instructions in chapter Web-Flashtool.

10. Modify firmware

    Note

    For the firmware to display the LiPo battery and its charge level, the corresponding compiler flags LIPO_ACCU_1200 and VOLTAGE_SENSOR must be set in the firmware file platformio.ini. You will need to create a customized firmware file and activate it in the OBP60 as Update. Details on firmware creation can be found in the chapter Gitpod.