![\"\"](\"http:\/\/embedded-lab.com\/blog\/wp-content\/uploads\/2012\/05\/chipKITUno32.jpg\" "\\"chipKITUno32\\"")
<\/a>chipKIT Uno32 board<\/p><\/div>\n
<\/p>\n
The complete description of the chipKIT Uno32 board can be found in its hardware manual<\/a> available from the Digilent’s website<\/a>. I am summarizing only the most important features here. Shown below is a picture, drawn by me, that shows the layout of the major components, jumpers, and connectors on the chipKIT Uno32 board.<\/p>\n Layout of the major components, connectors, and jumpers<\/p><\/div>\n Connection to PC<\/strong><\/p>\n The Uno32 board uses a standard Mini-B USB connector for connection to a USB port on the PC. The FTDI FT232RQ chip next to the USB connector provides an USB-UART interface for a two-way serial communication between the PC and the board. The same serial port is used by the MPIDE to communicate with the serial bootloader running on the Uno32 board while downloading user applications.<\/p>\n Power supply section<\/strong><\/p>\n The Uno32 can be powered either via USB or from an external power supply.\u00a0The automatic switch-over circuit on-board\u00a0causes the external supply to be used if both\u00a0supplies are present. There are two voltage regulators present in the Uno32 board. The first regulates the external supply voltage to 5V and powers the +5V bus line (VCC5V0<\/strong>) on the board. The second regulates the VCC5V0<\/strong> bus to\u00a03.3V that goes to the 3.3V bus (VCC3V3)<\/strong> and also powers the PIC32 microcontroller.\u00a0A 5.5 mm x 2.1 mm barrel connector is available to power the Uno32 board from an\u00a0external power supply (wall adapter). The center terminal of the connector is wired as the positive supply voltage.\u00a0The external power supply voltage must be in the range 7V to 15V.<\/p>\n Jumper JP2<\/strong> provides an option to route the external\u00a0power supply voltage through the on-board 5V\u00a0regulator or directly to the VCC5V0<\/strong> bus,\u00a0bypassing the on-board 5V regulator. Normally, JP2<\/strong> is in the REG<\/strong> position. This routes the external supply through the 5V regulator. If the external power supply is already a regulated +5V output, JP2<\/strong> can be placed in BYP<\/strong> position to power the VCC5V0<\/strong> bus directly from the external source.<\/p>\n The 6-pin POWER connector, J2<\/strong>, is used to power external circuits or shields connected to the Uno32 board. Pin 1 (RESET<\/strong>) is connected\u00a0to the MCLR\u00a0pin on the PIC32 microcontroller. This pin can be\u00a0used to reset the PIC32 from an external circuit. The second and third pins provide 3.3V (maximum current 425 mA) and 5.0V (maximum current 900 mA) output, respectively, to power an external circuit or a shield plugged into the Uno32 board. The total current provided by pins 2 and 3 together, however, shouldn’t exceed 925 mA. Pins 4 and 5 (GND<\/strong>) provide common ground connections between the Uno32 and any external circuit. Pin 6 (VIN<\/strong>) is connected to the input of the external power supply connector. This pin can be used to provide the unregulated input voltage to the external circuit or the shield connected to Uno32.<\/p>\n Digital I\/O pins<\/strong><\/p>\n The chipKIT and Arduino systems both use logical pin numbers to identify digital I\/O pins. The valid logical pin numbers for the Uno32 board are 0-43. The chipKIT Uno32 board provides altogether 42 I\/O pins that are accessible through connectors J5<\/strong>, J6<\/strong>, and J7<\/strong>. Each I\/O pin can source or sink a maximum of 18mA. However, to keep the output voltage within the specified voltage range (VOL = 0.4V, VOH = 2.4V), the pin current must be restricted to source and sink at most 7mA and 12mA, respectively. The maximum current that can be sourced or sunk across all I\/O pins simultaneously is 200mA.<\/p>\n Connectors J5<\/strong> and J6<\/strong> are 2×8 female pin header connectors that provide access to 30 I\/O pins. The outer row of pins (labeled 0 through 13, A, and G) corresponds to the I\/O connector pins on an Arduino Uno board. The inner row of pins (labeled 26 through 41) are the extra I\/O signals provided by the chipKIT Uno32.<\/p>\n Similarly, connector J7<\/strong> is a 2×6 female pin header that provides access to the analog input pins on the PIC32 microcontroller. The outer row of pins corresponds to the six analog pins (A0-A5) on an Arduino Uno board, whereas the inner row of pins are the additional analog channels (A6-A11) provided by the Uno32. These analog pins can also be used as digital I\/O pins. In that case, the logical pin numbers of A0-A11 would be 14-25.<\/p>\n So the total 42 I\/O pins are distributed as follows:<\/p>\n The pin labeled as A<\/strong> on J5<\/strong> is used to provide an external reference voltage for the microcontroller’s A\/D converter. But it can also be used as a digital I\/O pin, and its logical pin number is 42.<\/p>\n Pulse width modulation (PWM) pins<\/strong><\/p>\n The I\/O pins 3, 5, 6, 9, and 10 can also be configured to provide PWM outputs.<\/p>\n LEDs on the board<\/strong><\/p>\n There are 5 LEDs (labeled as LED1<\/strong> through LED5<\/strong>) on the chipKIT Uno32 board. LED1<\/strong> and LED2<\/strong> are communication status LEDs and they will blink when data is being sent or received between the Peripheral functions<\/strong><\/p>\n The PIC32 microcontroller on the Uno32 board provides a number of peripheral functions. The following peripherals are provided:<\/p>\n<\/a>\n
\nUno32 and the PC over the serial connection. LED3<\/strong> is located next to the barrel connector for external DC supply, and is basically the power-on indicator LED. The Uno32 board has two user LEDs, labeled LED4<\/strong> and LED5<\/strong>, that are connected to digital I\/O Pins 13 and 43. It should be noted that Pin 43 only goes to\u00a0LED5<\/strong> and not any connector pin. Driving the pin high turns LED5<\/strong> on, driving it low turns it off.<\/p>\n\n
\n
\n
\n
\n
\n