ARM Cortex M3

NGX Technologies sent us this Blueboard LPC1768-H to play with. It’s basically a breakout board for an NXP LPC1768 ARM cortex-M3 microcontroller (datasheet). The board adds a few extra goodies, such as a choice of mini-USB connector or barrel-jack to provide regulated power to the chip. There’s also a clock crystal for the internal RTC and an Atmel 256kb EEPROM chip. This chip has 70 I/O ports, accessed through the pin headers on top and bottom of the board. The 20-pin header to the left is for a JTAG programmer (yes, you’ll need a separate programmer). Coming in at only $32.78 this is a very accessible route for projects that require more power than some of the traditional hobby controllers. The shipping seems to have come down since NGX’s last offering, now it would be under $10 to ship to the States.

The LPC1768 is the same controller from the mbed that we reviewed. What’s missing is some of the interface hardware and the boot-loader, but the tradeoff comes with a $66 savings. This is to mbed what an AVR board is to the Arduino, a way to get even closer to the hardware.

There are a few things we think are missing. Most notably, there isn’t a datasheet or user guide for the board itself.  The only information available is a schematic (PDF), but that should be enough for those already well versed in working with microcontrollers. There is also a 12MHz clock crystal on the board but it doesn’t seem to be jumpered in case you wanted to use a different frequency. We’re not sure if this is much of an issue, the internal RC oscillators offer a lot of flexibility including operation up to 100MHz.

We feel this is a solid platform that will help to get more people into ARM development because of its low price.

Summary:
BlueBoard-LPC1768-H is a breakout board for LPC1768 cortex-M3 based microcontroller. The LPC1768 microcontroller has 512KB of internal flash and 64KB RAM. Ethernet MAC, USB Device/Host/OTG interface, 8-channel general purpose DMA controller, 4 UARTs, 2 CAN channels, 2 SSP controllers, SPI interface, 3 I2C-bus interfaces, 2-input plus 2-output I2S-bus interface, 8-channel 12-bit ADC, 10-bit DAC, motor control PWM, Quadrature Encoder interface, 4 general purpose timers, 6-output general purpose PWM, ultra-low power Real-Time Clock (RTC) with separate battery supply, and up to 70 general purpose I/O pins

Following are the salient features of the board.

• Dimensions: 94.08x54.48 mm2
• Two layer PCB (FR-4 material)
• Power: USB powered or can be powered through the DC jack, 5-7.5V input
• reset switch
• Test LED
• 32Khz crystal for RTC
• On board 258kb I2C EERPOM
• Extension headers for all microcontroller pins
• USB B-type connector for powering the board
• 20pin - JTAG connector

Schematics
Sample Code
User Manual