Hardware design needs analysis completed after thestart, rabbits using Cadence 16.6 tools. Schematics tools for OrCAD Capture CIS,PCB tools for Allegro PCB Editor.
First is the IDPROM, EEPROM I2C0 connected with the raspberry pie. This part of the circuit is a reservedfunction, actual production is not installed (without actually welding devices with NC).
Users use GPIO irrigation LED current control, when IO low LED lights.
Left level the key part can by GPIO button implementation, press releases for the high level, pressed for the low level. Not add hardware for jitters eliminationhere, need software.
Infrared emission tube current is large, it is controlled through a GPIO NPN transistor to drive an infraredLED, high-voltage infrared tube conduction. Can be welded using a LED, use two LED to enhanced infrared signals.
Infrared receiver with integrated receiver HS0038, can work in the 3.3V voltage, use a GPIO to receive infrared signals.
Active buzzer also need high current, and infra-red tube the transistor-driven, GPIO high voltage buzzer sound.
Digital display with two 4-digit 7-segment digital tube (common cathode, include a decimal point is actually 8), and driving through the MAX7219. MAX7219 up to 8 8-bit display, code A~DP in order to connect both the MAX7219 digital control, used to displaythe contents of each and every. MAX7219 digital (Digital) select signal are connected to two pieces of digital public end.
MAX7219 SPI connected with the raspberry pie, due to the need to control not only needs to read information, DOUT is not answered. Chip uses 5V power supply, SPI 5V level should be used in the strict sense, by the raspberry 3.3V level can also be normal control, but recommended settings for level conversion circuit.
Finally, interface expansion header, threaded 100ohm resistance current-limiting protection. Each interface provides 3.3V power supply and GND respectively.
ICA HAT PCB using the cheap double-sided boards (production 10 pieces of PCB 50RMB), to be sure the layout.
According to the dominant user behavior, digital control and emissions on the upper part of the Board (the most visible place), the button in the right corner of the Board (left-handed friends on the left). IR transceiver and edge IO interface is neatly arranged in four weeks in order to prevent blocking and easy wiring. Others such as LED and buzzer in the middle of the Board select places.
PCB design files can be exported as Gerber (Artwork) and drill (Drill) file to the PCB manufacturers, domestic manufacturers generally accept the Altium Designer and Protel format of project files, but also convert to Gerber for the production. Manufacturers will also offer free tests, ensure the circuit does not appear, such as short circuit, PCB for all the figure below:
SMT PCB production is devices, welding machine if required to provide production of steel with Solder Mask (Solder Mask) file, and are used to machine SMD Assembly (Assembly) files.
Here as the device is simple little rabbits using manual mode. Welding to weld intensive difficult pin SMDIC, then welded low chip devices, and finally welded high-line devices. Connector and digital can be finally welded. Below is the manual completed circuit boards, which we call PCBA:
Need to be aware of is that testing is required after welding is complete circuit is shorted, especially power supply short circuit and power-on test. Otherwise, may burn out HAT the Board also has the potential to damage the Brambles Board.