MCP2200 breakout board

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Project Summary
Name: MCP2200 breakout board
Buy it: Get one for $15 at Seeed Studio
Price: $15
Status: Test production
Manufacturing: Shipping
Forum: MCP2200 breakout board Forum
Mcp2200-breakout-seeed.jpg

Available now for $15 at Seeed Studio.

The MCP2200 is a new USB to serial converter chip from Microchip. This breakout board brings all the pins to bread-board friendly headers.

  • USB CDC virtual serial port interface
  • Secondary HID configuration interface
  • Up to 8 additional IO
  • 256bytes user EEPROM
  • TX/RX indicator LEDs
  • All pins to bread-board friendly header

The MCP2200 is actually just a PIC 18F14K50 programmed with a firmware, but it's slightly less expensive than the PIC alone.

Contents

Hardware

Mcp2200-breakout-v1-cct.png

Click for a full size schematic image. Schematic and PCB were designed with the freeware version of Cadsoft Eagle, download the latest project files from our Google Code project SVN.

MCP2200

Mcp2200-cct-basic-circuit.png

The MCP2200 is actually a PIC 18F14K50 with a special firmware put into it. It requires the same sort of support circuit that a PIC does:

  • A reset pin is held high for normal operation with a 1K pull-up resistor (R6)
  • C1 is a decoupling capacitor (1uF) for the single MCP2200 supply pin
  • An internal 3.3volt regulator supplies the USB peripheral, it requires an external 470nF capacitor (C2)
  • A 12Mhz crystal(Y1) and two 27pF capacitor (C3,C4) provide the clock

The chip is powered directly from the 5volt USB supply. Ferrite bead (L1) and 10uF capacitor (C5) filter the supply (not shown).

LEDs

LED connections
LED PinIndicates
D1 GP6USB RX
D2 GP7 USB TX
D3 GP0 /SUSPEND
D4 GP1 CONFIG

Four LEDs (D1-D4) are connected to the MCP2200 status indicator pins, as shown above. Each LED has a 1K current limiting resistor (R1-R4).

PCB

Mcp2200-breakout-pcb.jpg

We used the freeware version of Cadsoft Eagle to make the schematic and PCB. Download the latest board files from SVN.

Some parts are little close in places, especially around the crystal. If you've soldered surface mount boards before this shouldn't be a challenge.

We brought the most common UART signals to a secondary header at the edge of the PCB. This makes it easier to use with a breadboard.

Partslist

Mcp2200-breakout-board.png

Click for a full size placement image.

partlist
Part Quantity Value Package
C1 1 1uF C805
C2 1 470nF C805
C3, C4 2 27pF C805
C5 1 10uF SMC_A
LED1-4 4 LED LED-805
IC1 1 MCP2200SS (Microchip USB->serial converter) SSOP20
L1 1 Ferrite bead 800mA+ FB805
R1-R4, R6 5 1k R805
X1 1 USB MINIB SMD CONN_MINI_USB_B
Y1 1 12Mhz crystal SMD 4X6

The latest sources and distributors are in the master partlist. See something missing? Please let us know.

Drivers

Mcp2200-install-1.png

The MCP2200 appears as a USB CDC (virtual serial port) device. Windows already has a driver, but you need to assign it with an .inf file.

Mcp2200-install-2.png

The first time you plug-in adapter Windows will prompt for driver. Point windows to the .inf file supplied in the Microchip download.

Mcp2200-device-manager.png

After the driver is installed you can go to Windows control panel and see the serial port number assigned to the device.

Configuration utility

Mcp2200-config-utility.png

In addition to the USB serial port interface, the MCP2200 has a second USB HID interface used to set the device configuration.

A utility in the MCP2200 driver download can program a custom USB VID and PID, change the behavior of the indicator LEDs, and modify other configuration options.

Issues with the MCP2200

Windows XP SP3+ required

Windows XP issues: SP3 or later required!

This is a composite USB device (serial port and HID configuration channel). A composite serial device will only work on Windows XP SP3 and higher. The device will connect and the transmit LED will blink (if configured) but no data is actually sent or received. Read more here and here.

RTS/CTS

RTS/CTS are handled locally on the chip!

The CDC serial device specification doesn't include CTS or RTS. The firmware in the MCP2200 handles the RTS and CTS signals internally. This means it probably can't reset your Arduino for programming.

Get one!

Mcp2200-breakout-seeed.jpg

You can get one for $15.

Your purchases at Seeed Studio keep the open source project coming, we sincerely appreciate your support!

Resources

License

  • CC-0, reference boards shouldn't be copyrighted!