If you are using the Bluefruit LE Shield then you have an SPI-connected NRF51822 module. You can use this with Atmega328 (Arduino UNO or compatible), ATmega32u4 (Arduino Leonardo, compatible) or ATSAMD21 (Arduino Zero, compatible) and possibly others.
Your pinouts are Hardware SPI, CS = 8, IRQ = 7, RST = 4
Bluefruit Micro or Feather 32u4 Bluefruit
If you have a Bluefruit Micro or Feather 32u4 Bluefruit LE then you have an ATmega32u4 chip with Hardware SPI, CS = 8, IRQ = 7, RST = 4
Feather M0 Bluefruit LE
If you have a Feather M0 Bluefruit LE then you have an ATSAMD21 chip with Hardware SPI, CS = 8, IRQ = 7, RST = 4
Bluefruit LE SPI Friend
If you have a stand-alone module, you have a bit of flexibility with wiring however we strongly recommend Hardware SPI, CS = 8, IRQ = 7, RST = 4
You can use this with just about any microcontroller with 5 or 6 pins
Bluefruit LE UART Friend or Flora BLE
If you have a stand-alone UART module you have some flexibility with wiring. However we suggest hardware UART if possible. You will likely need to use the flow control CTS pin if you are not using hardware UART. There's also a MODE pin
You can use this with just about any microcontroller with at least 3 pins, but best used with a Hardware Serial/UART capable chip!
Configure the Pins Used
You'll want to check the Bluefruit Config to set up the pins you'll be using for UART or SPI
Each example sketch has a secondary tab with configuration details. You'll want to edit and save the sketch to your own documents folder once set up.
Common settings:
You can set up how much RAM to set aside for a communication buffer and whether you want to have full debug output. Debug output is 'noisy' on the serial console but is handy since you can see all communication between the micro and the BLE
// ---------------------------------------------------------------------------------------------- // These settings are used in both SW UART, HW UART and SPI mode // ---------------------------------------------------------------------------------------------- #define BUFSIZE 128 // Size of the read buffer for incoming data #define VERBOSE_MODE true // If set to 'true' enables debug output
Software UART
If you are using Software UART, you can set up which pins are going to be used for RX, TX, and CTS flow control. Some microcontrollers are limited on which pins can be used! Check the SoftwareSerial library documentation for more details
// SOFTWARE UART SETTINGS #define BLUEFRUIT_SWUART_RXD_PIN 9 // Required for software serial! #define BLUEFRUIT_SWUART_TXD_PIN 10 // Required for software serial! #define BLUEFRUIT_UART_CTS_PIN 11 // Required for software serial! #define BLUEFRUIT_UART_RTS_PIN -1 // Optional, set to -1 if unused
Hardware UART
If you have Hardware Serial, there's a 'name' for it, usually Serial1 - you can set that up here:
// HARDWARE UART SETTINGS #ifdef Serial1 // this makes it not complain on compilation if there's no Serial1 #define BLUEFRUIT_HWSERIAL_NAME Serial1 #endif
Mode Pin
For both hardware and software serial, you will likely want to define the MODE pin. There's a few sketches that dont use it, instead depending on commands to set/unset the mode. Its best to use the MODE pin if you have a GPIO to spare!
#define BLUEFRUIT_UART_MODE_PIN 12 // Set to -1 if unused
SPI Pins
For both Hardware and Software SPI, you'll want to set the CS (chip select) line, IRQ (interrupt request) line and if you have a pin to spare, RST (Reset)
// SHARED SPI SETTINGS #define BLUEFRUIT_SPI_CS 8 #define BLUEFRUIT_SPI_IRQ 7 #define BLUEFRUIT_SPI_RST 4 // Optional but recommended, set to -1 if unused
Software SPI Pins
If you don't have a hardware SPI port available, you can use any three pins...its a tad slower but very flexible
// SOFTWARE SPI SETTINGS #define BLUEFRUIT_SPI_SCK 13 #define BLUEFRUIT_SPI_MISO 12 #define BLUEFRUIT_SPI_MOSI 11
Select the Serial Bus
Once you've configured your pin setup in the BluefruitConfig.h file, you can now check and adapt the example sketch.
The Adafruit_BluefruitLE_nRF51 library supports four different serial bus options, depending on the HW you are using: SPI both hardware and software type, and UART both hardware and software type.
UART Based Boards (Bluefruit LE UART Friend & Flora BLE)
This is for Bluefruit LE UART Friend & Flora BLE boards. You can use either software serial or hardware serial. Hardware serial is higher quality, and less risky with respect to losing data. However, you may not have hardware serial available! Software serial does work just fine with flow-control and we do have that available at the cost of a single GPIO pin.
For software serial (Arduino Uno, Adafruit Metro) you should uncomment the software serial contructor below, and make sure the other three options (hardware serial & SPI) are commented out.
// Create the bluefruit object, either software serial...uncomment these lines
SoftwareSerial bluefruitSS = SoftwareSerial(BLUEFRUIT_SWUART_TXD_PIN, BLUEFRUIT_SWUART_RXD_PIN);
Adafruit_BluefruitLE_UART ble(bluefruitSS, BLUEFRUIT_UART_MODE_PIN,
BLUEFRUIT_UART_CTS_PIN, BLUEFRUIT_UART_RTS_PIN);
For boards that require hardware serial (Adafruit Flora, etc.), uncomment the hardware serial constructor, and make sure the other three options are commented out
/* ...or hardware serial, which does not need the RTS/CTS pins. Uncomment this line */ Adafruit_BluefruitLE_UART ble(BLUEFRUIT_HWSERIAL_NAME, BLUEFRUIT_UART_MODE_PIN);
SPI Based Boards (Bluefruit LE SPI Friend)
For SPI based boards, you should uncomment the hardware SPI constructor below, making sure the other constructors are commented out:
/* ...hardware SPI, using SCK/MOSI/MISO hardware SPI pins and then user selected CS/IRQ/RST */ Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_CS, BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);
If for some reason you can't use HW SPI, you can switch to software mode to bit-bang the SPI transfers via the following constructor:
/* ...software SPI, using SCK/MOSI/MISO user-defined SPI pins and then user selected CS/IRQ/RST */
Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_SCK, BLUEFRUIT_SPI_MISO,
BLUEFRUIT_SPI_MOSI, BLUEFRUIT_SPI_CS,
BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);
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