The blend is an integrated development board, we have "blend" ed Arduino with Bluetooth 4.0 Low Energy (aka BLE or Bluetooth Smart) into a single board. It is targeted for makers to develop low power Internet-Of-Things (IoT) projects quickly and easily. The blend is 100% compatible with sketches and Shields that work with Arduino Leonardo. The micro-controller unit (MCU) is Atmel ATmega32U4 and the BLE chip is Nordic nRF8001. Blend runs as BLE peripheral role only, it allows BLE central role devices to establish a connection with.
- •iPhone 4s
- •iPhone 5 (all models)
- •iPod touch 5
- •iPad 3/4/mini/Air
- •Nexus 4
- •Nexus 5
- •Nexus 7
- •(please report any other Android devices supported)
- •Nokia Lumia 630
- •(please report any other Windows Phone devices supported)
- Utilize Nordic Bluetooth Smart SDK for Arduino
- Software development using Arduino IDE
- Works with our free Android App and iOS App
- Support 5V and 3.3V operating voltage
- Selectable REQN and RDYN pins, from pin 0 to 3, 6 to 11
- Flexible RF RESET pin, pin 4 or 5
- The over-the-air download of the sketch to Blend (available soon)
- Besides the on-board PCB antenna, option to use an SMA connector for the external antenna (soldering is required)
- Operating Voltage: 3.3V or 5V
- Microcontroller: Atmel ATmega32U4
- Wireless Chip: Nordic nRF8001
- Input Voltage:
- 5V (USB)
- 5-12V (DC input or VIN)
Note: Use only one power source at a time, otherwise you will damage the board.
- Clock Speed: 16MHz
- Bluetooth 4.0 Low Energy
- Serial (TX/RX)
- Flash Memory: 32KB (of which 4 KB used by bootloader)
- SRAM: 2.5KB
- EEPROM: 1KB
- I/O Pins: 20
- Dimensions: 73 x 54 x 12mm (120 x 73 x 25mm with packaging)
- Weight: 19g (37g with packaging)
How It Works
The nRF8001 chip communicates with ATmega32U4 through the ACI (Application Controller Interface). The ACI is similar to SPI but not actually work as SPI. SPI is consists of MOSI, MISO, SCK, and SS, whereas ACI is consists of MOSI, MISO, SCK, REQN, and RDYN.
Since the nRF8001 chip may receive data anytime even not selected by SPI master (Atmega32U4), so the SS line is not needed.
For the ACI, data exchange still through MOSI and MISO, and SCK provides the clock generated by the master.
When the master wants to request data from BLE Shield, it puts the REQN to low until the RDYN line is put too low by BLE Shield, and then the master generates the clock to read out the data. After reading out the data, the master will release the REQN and BLE Shield release the RDYN, put them too high.
If the nRF8001 has data to transmit to the master, it will put the RDYN to low to indicate master, even though the master has not requested data and REQN is idle. If the master detects a low-level condition on RDYN, it will put REQN to low and generate the clock to read out the data. After reading out the data, both REQN and RDYN will be put too high. Note that REQN is controlled by the master while RDYN is controlled by the nRF8001 chip.
Operate at 3.3V or 5V
According to the Atmega32U4 specification, the MCU can run at either 8MHz@3.3V or 16MHz@5V. Normally, you should set the voltage selection switch to 5V to run the board at 16MHz. However, if you need to connect to shields or external components, such as sensors or MCU, which accept 3.3V only, you should change the operating voltage to 3.3V using the voltage selection switch.
Note that while Blend is running at 3.3V, the Atmega32U4 will still run at 16MHz which is outside Atmel's specification, the CPU is overclocked (we have not seen any issue so far).
Part List: 1x Blend V1.0 - Arduino and BLE(Bluetooth Low Energy)