zhaijinbao/cdpnp

Compact desktop semi-automatic SMT prototyping machine

CDPnP

The CDPnP is an SMT assistant tool, not a fully automatic SMT machine.

Fully automatic SMT machines are much more complicated to configure, requiring the configuration of feeders and the configuration of components in the software, and the machine is much larger.

This semi-automatic machine is simple to configure, just import the KiCad generated position file, place one or more PCBs, use the camera to mark any two reference points on each PCB and you are ready to go. All components do not need to be configured in software.

For ICs with very dense pins, especially for BGA packages, it is recommended to check the position manually before putting them down and use the keyboard to adjust the position and angle. If you place them directly by hand, it is not easy to align them and they are prone to hand shake.

Discussions for this project have been enabled, so feel free to join our discussions and get more information posted.

Hardware

The hardware is modular in design. A CDBUS (RS-485) bus is used to connect all modules to the PC, including two cameras. (10 Mbps by default.)

The machine has four degrees of freedom: X, Y, Z, R (rotate, also with homing switch), and is controlled by multiple stepper motor controllers.

The Y-axis is controlled by two motor controllers, synchronised by multicasting.

The Z-axis contains a strain gauge-based force sensor, the sensor data is relayed through the R-axis controller, as the sensor is closest to the R-axis.

The machine automatically picks up component from a pre-defined search areas and put it onto the PCB in the corresponding position.

Whenever the machine has finished with the same value of components, it will automatically pause and wait for the user to change the components in the search area.

The stepper motor controllers and camera mentioned above are all open source projects. Available at: https://github.com/dukelec/cdbus_gui

In the future, it will be possible to move components as well as flip components by adding a flexible feeding device (3-axis vibration).

User Interface

The components list can be dragged and sorted.

Click on a component in the list and the camera will automatically move to it.

Click on the run button to start the semi-automatic SMT placement process.

Also supports more than two PCBs, which are automatically hidden in the picture.

The following pictures show the recognition of the 0402, 0201 and sot23 footprints for reference only. In practice, only components with same value can be placed at any one time.

Download this GUI tool:

git clone --recurse-submodules https://github.com/dukelec/cdpnp.git

Update:

git pull --recurse-submodules

Dependence:

Python version >= 3.8
pip3 install pythoncrc websockets pyserial u-msgpack-python aiohttp opencv-python scipy

Usage:

Run pnp_main.py or start.sh, then open url in your web browser: http://localhost:8900

Test without hardware: ./pnp_main.py --debug --dev None

App shortcuts: doc/shortcuts.md

The protocols between mcu, python, and web page please refer to the CDBUS_GUI project.