이름 : Abigail
이메일 : abigailparkhurst@aol.com
연락처 :
예식일 : How Fast can you Go?
문의내용:

Now that the schematic is laid out, I can show you the board layout. The only real thing of note on this schematic is the pin assignments for peripherals. The drawback to using literally every I/O pin is that the bypass capacitors are a little further away from the RP2040 than they could be, but, RS485 standard the RP2040 seems more than happy with this layout in practice. It's also well suited for this project: there's a lot of digital peripherals to talk to but no analog stuff to deal with which pairs well with the RP2040's abundance of digital I/O and near lack of analog I/O. But a lot of RS-485 hardware uses only 1 pair of wires (half-duplex). Ideally, the two ends of the cable will have a termination resistor connected across the two wires. They can easily update one PC, which will take care of all prices to the store.

Special care must be made with the 1.1 V rail as it provides power to the CPU core. Ensure that the TVS diode is close to the power connectors to reduce the overall current loop for an outside transient voltage spike. TODO: add connectors and pins from manufacturers such as NI, B&B, ADAM, etc. Volunteers? Place the two USB termination resistors (R303 and R304) close to their respective pins on the RP2040. Ensure that the bypass capacitors for the 5 V converter and the 3.3 V regulator are as close as possible to their respective pins. Since the drop from 5 V to 3.3 V and the current demands are rather small, a simple linear regulator works well here. Of course, the 3.3 V rail also has an obligatory indicator LED (D205, R204). I've also added an indicator LED for the 5 V rail (D204, R203). If I have room on a design I always include indicator LEDs on every power rail.

It needs to accurately move the gantry around, control vacuum-powered picking nozzles, and communicate with various digital peripherals such as RGB LEDs and automated feeders. This article will explore the hardware design of Starfish, a control board for a pick and place machine built around the Raspberry Pi RP2040 microcontroller and Trinamic TMC2209 motor drivers. I chose the RP2040 because I've been wanting to do a project with it and it's currently the easiest microcontroller to get my hands on. The MIC5317 can provide up to 150 mA of downstream current which should be more than enough for the RP2040 and its companions. An ESD protection TVS diode array (U403) is used to protect the USB data lines from voltage transients that can often occur when plugging and unplugging cables. The TVS diode is there for exactly what it's designed for - transient voltage suppression. Immediately following the screw terminals is a 3 A fuse (F201) and a SMAJ28CA bidirectional transient voltage suppression (TVS) diode (D201). The extra screw terminal is for daisy-chaining power to other boards. Starting from the left, the power comes in through screw terminals (J201, J202).

Make sure power traces and fills are large enough to accommodate the expected current. Read Next:What are FAT and SAT? It's useful to reference the RP2040 datasheet's pin function table (section 1.4.3) when making those serial connections as there are a few caveats to watch out for. Next up is the brains - the Raspberry Pi RP2040. The driver must not exceed 10V differential, or 6V common mode (outputs relative to circuit common). Starfish runs on 24 VDC, interfaces with some noisy peripherals, and needs to be resilient against common power faults. Opportunity to work with plug-ins to increase the number of interfaces available (see accessories section). This leads to a circuit that is more defensive that you might usually see. All devices, or units, on the link generate an electrical load to produce or detect this voltage, increasing with the addition of more devices and units. Last, but not least, is a large bulk capacitor (C203) to give the board a little more breathing room when dealing with sudden current draws. After a silly incident that was entirely my fault, I managed to fry the STM32 on the board.