pca10040
Constants
const HasLowFrequencyCrystal = true The PCA10040 has a low-frequency (32kHz) crystal oscillator on board.
const ( LED1Pin= 17 LED2Pin= 18 LED3Pin= 19 LED4Pin= 20 LEDPin= LED1 ) LEDs on the PCA10040 (nRF52832 dev board)
const ( BUTTON1Pin= 13 BUTTON2Pin= 14 BUTTON3Pin= 15 BUTTON4Pin= 16 BUTTONPin= BUTTON1 ) Buttons on the PCA10040 (nRF52832 dev board)
const ( UART_TX_PINPin= 6 UART_RX_PINPin= 8 ) UART pins for NRF52840-DK
const ( ADC0Pin= 3 ADC1Pin= 4 ADC2Pin= 28 ADC3Pin= 29 ADC4Pin= 30 ADC5Pin= 31 ) ADC pins
const ( SDA_PINPin= 26 SCL_PINPin= 27 ) I2C pins
const ( SPI0_SCK_PINPin= 25 SPI0_SDO_PINPin= 23 SPI0_SDI_PINPin= 24 ) SPI pins
const ( TWI_FREQ_100KHZ= 100000 TWI_FREQ_400KHZ= 400000 ) TWI_FREQ is the I2C bus speed. Normally either 100 kHz, or 400 kHz for high-speed bus.
Deprecated: use 100 * machine.KHz or 400 * machine.KHz instead.
const ( // I2CReceive indicates target has received a message from the controller. I2CReceiveI2CTargetEvent= iota // I2CRequest indicates the controller is expecting a message from the target. I2CRequest // I2CFinish indicates the controller has ended the transaction. // // I2C controllers can chain multiple receive/request messages without // relinquishing the bus by doing 'restarts'. I2CFinish indicates the // bus has been relinquished by an I2C 'stop'. I2CFinish ) const ( // I2CModeController represents an I2C peripheral in controller mode. I2CModeControllerI2CMode= iota // I2CModeTarget represents an I2C peripheral in target mode. I2CModeTarget ) const Device = deviceName Device is the running program’s chip name, such as “ATSAMD51J19A” or “nrf52840”. It is not the same as the CPU name.
The constant is some hardcoded default value if the program does not target a particular chip but instead runs in WebAssembly for example.
const ( KHz= 1000 MHz= 1000_000 GHz= 1000_000_000 ) Generic constants.
const NoPin = Pin(0xff) NoPin explicitly indicates “not a pin”. Use this pin if you want to leave one of the pins in a peripheral unconfigured (if supported by the hardware).
const ( PinInputPinMode= (nrf.GPIO_PIN_CNF_DIR_Input << nrf.GPIO_PIN_CNF_DIR_Pos) | (nrf.GPIO_PIN_CNF_INPUT_Connect << nrf.GPIO_PIN_CNF_INPUT_Pos) PinInputPullupPinMode= PinInput | (nrf.GPIO_PIN_CNF_PULL_Pullup << nrf.GPIO_PIN_CNF_PULL_Pos) PinInputPulldownPinMode= PinInput | (nrf.GPIO_PIN_CNF_PULL_Pulldown << nrf.GPIO_PIN_CNF_PULL_Pos) PinOutputPinMode= (nrf.GPIO_PIN_CNF_DIR_Output << nrf.GPIO_PIN_CNF_DIR_Pos) | (nrf.GPIO_PIN_CNF_INPUT_Connect << nrf.GPIO_PIN_CNF_INPUT_Pos) ) const ( PinRisingPinChange= nrf.GPIOTE_CONFIG_POLARITY_LoToHi PinFallingPinChange= nrf.GPIOTE_CONFIG_POLARITY_HiToLo PinTogglePinChange= nrf.GPIOTE_CONFIG_POLARITY_Toggle ) Pin change interrupt constants for SetInterrupt.
const ( P0_00Pin= 0 P0_01Pin= 1 P0_02Pin= 2 P0_03Pin= 3 P0_04Pin= 4 P0_05Pin= 5 P0_06Pin= 6 P0_07Pin= 7 P0_08Pin= 8 P0_09Pin= 9 P0_10Pin= 10 P0_11Pin= 11 P0_12Pin= 12 P0_13Pin= 13 P0_14Pin= 14 P0_15Pin= 15 P0_16Pin= 16 P0_17Pin= 17 P0_18Pin= 18 P0_19Pin= 19 P0_20Pin= 20 P0_21Pin= 21 P0_22Pin= 22 P0_23Pin= 23 P0_24Pin= 24 P0_25Pin= 25 P0_26Pin= 26 P0_27Pin= 27 P0_28Pin= 28 P0_29Pin= 29 P0_30Pin= 30 P0_31Pin= 31 ) Hardware pins
const ( Mode0= 0 Mode1= 1 Mode2= 2 Mode3= 3 ) SPI phase and polarity configs CPOL and CPHA
const ( // ParityNone means to not use any parity checking. This is // the most common setting. ParityNoneUARTParity= iota // ParityEven means to expect that the total number of 1 bits sent // should be an even number. ParityEven // ParityOdd means to expect that the total number of 1 bits sent // should be an odd number. ParityOdd ) Variables
var DefaultUART = UART0 var ( ErrTimeoutRNG= errors.New("machine: RNG Timeout") ErrClockRNG= errors.New("machine: RNG Clock Error") ErrSeedRNG= errors.New("machine: RNG Seed Error") ErrInvalidInputPin= errors.New("machine: invalid input pin") ErrInvalidOutputPin= errors.New("machine: invalid output pin") ErrInvalidClockPin= errors.New("machine: invalid clock pin") ErrInvalidDataPin= errors.New("machine: invalid data pin") ErrNoPinChangeChannel= errors.New("machine: no channel available for pin interrupt") ) var ( // UART0 is the hardware UART on the NRF SoC. _UART0= UART{Buffer: NewRingBuffer()} UART0= &_UART0 ) UART
var Flash flashBlockDevice var ( PWM0= &PWM{PWM: nrf.PWM0} PWM1= &PWM{PWM: nrf.PWM1} PWM2= &PWM{PWM: nrf.PWM2} ) PWM
var ( SPI0= &SPI{Bus: nrf.SPIM0, buf: new([1]byte)} SPI1= &SPI{Bus: nrf.SPIM1, buf: new([1]byte)} SPI2= &SPI{Bus: nrf.SPIM2, buf: new([1]byte)} ) There are 3 SPI interfaces on the NRF528xx.
var ( I2C0= &I2C{Bus: nrf.TWI0} I2C1= &I2C{Bus: nrf.TWI1} ) There are 2 I2C interfaces on the NRF.
var ( ErrPWMPeriodTooLong = errors.New("pwm: period too long") ) var Serial = DefaultUART Serial is implemented via the default (usually the first) UART on the chip.
var ( ErrTxInvalidSliceSize= errors.New("SPI write and read slices must be same size") errSPIInvalidMachineConfig= errors.New("SPI port was not configured properly by the machine") ) func CPUFrequency
func CPUFrequency() uint32 func CPUReset
func CPUReset() CPUReset performs a hard system reset.
func DeviceID
func DeviceID() []byte DeviceID returns an identifier that is unique within a particular chipset.
The identity is one burnt into the MCU itself, or the flash chip at time of manufacture.
It’s possible that two different vendors may allocate the same DeviceID, so callers should take this into account if needing to generate a globally unique id.
The length of the hardware ID is vendor-specific, but 8 bytes (64 bits) is common.
func FlashDataEnd
func FlashDataEnd() uintptr Return the end of the writable flash area. Usually this is the address one past the end of the on-chip flash.
func FlashDataStart
func FlashDataStart() uintptr Return the start of the writable flash area, aligned on a page boundary. This is usually just after the program and static data.
func GetRNG
func GetRNG() (ret uint32, err error) GetRNG returns 32 bits of non-deterministic random data based on internal thermal noise. According to Nordic’s documentation, the random output is suitable for cryptographic purposes.
func InitADC
func InitADC() InitADC initializes the registers needed for ADC.
func InitSerial
func InitSerial() func NewRingBuffer
func NewRingBuffer() *RingBuffer NewRingBuffer returns a new ring buffer.
func ReadTemperature
func ReadTemperature() int32 ReadTemperature reads the silicon die temperature of the chip. The return value is in milli-celsius.
type ADC
type ADC struct { Pin Pin } func (*ADC) Configure
func (a *ADC) Configure(config ADCConfig) Configure configures an ADC pin to be able to read analog data. Reference voltage can be 150, 300, 600, 1200, 1800, 2400, 3000(default), 3600 mV Resolution can be 8, 10, 12(default), 14 bits SampleTime will be ceiled to 3(default), 5, 10, 15, 20 or 40(max) µS respectively Samples can be 1(default), 2, 4, 8, 16, 32, 64, 128, 256 samples
func (*ADC) Get
func (a *ADC) Get() uint16 Get returns the current value of an ADC pin in the range 0..0xffff.
type ADCConfig
type ADCConfig struct { Referenceuint32// analog reference voltage (AREF) in millivolts Resolutionuint32// number of bits for a single conversion (e.g., 8, 10, 12) Samplesuint32// number of samples for a single conversion (e.g., 4, 8, 16, 32) SampleTimeuint32// sample time, in microseconds (µs) } ADCConfig holds ADC configuration parameters. If left unspecified, the zero value of each parameter will use the peripheral’s default settings.
type BlockDevice
type BlockDevice interface { // ReadAt reads the given number of bytes from the block device. io.ReaderAt // WriteAt writes the given number of bytes to the block device. io.WriterAt // Size returns the number of bytes in this block device. Size() int64 // WriteBlockSize returns the block size in which data can be written to // memory. It can be used by a client to optimize writes, non-aligned writes // should always work correctly. WriteBlockSize() int64 // EraseBlockSize returns the smallest erasable area on this particular chip // in bytes. This is used for the block size in EraseBlocks. // It must be a power of two, and may be as small as 1. A typical size is 4096. EraseBlockSize() int64 // EraseBlocks erases the given number of blocks. An implementation may // transparently coalesce ranges of blocks into larger bundles if the chip // supports this. The start and len parameters are in block numbers, use // EraseBlockSize to map addresses to blocks. EraseBlocks(start, len int64) error } BlockDevice is the raw device that is meant to store flash data.
type I2C
type I2C struct { Bus*nrf.TWI_Type modeI2CMode } I2C on the NRF51 and NRF52.
func (*I2C) Configure
func (i2c *I2C) Configure(config I2CConfig) error Configure is intended to setup the I2C interface.
func (*I2C) ReadRegister
func (i2c *I2C) ReadRegister(address uint8, register uint8, data []byte) error ReadRegister transmits the register, restarts the connection as a read operation, and reads the response.
Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily read such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.
func (*I2C) SetBaudRate
func (i2c *I2C) SetBaudRate(br uint32) error SetBaudRate sets the I2C frequency. It has the side effect of also enabling the I2C hardware if disabled beforehand.
func (*I2C) Tx
func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) Tx does a single I2C transaction at the specified address. It clocks out the given address, writes the bytes in w, reads back len(r) bytes and stores them in r, and generates a stop condition on the bus.
func (*I2C) WriteRegister
func (i2c *I2C) WriteRegister(address uint8, register uint8, data []byte) error WriteRegister transmits first the register and then the data to the peripheral device.
Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily write to such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.
type I2CConfig
type I2CConfig struct { Frequencyuint32 SCLPin SDAPin ModeI2CMode } I2CConfig is used to store config info for I2C.
type I2CMode
type I2CMode int I2CMode determines if an I2C peripheral is in Controller or Target mode.
type I2CTargetEvent
type I2CTargetEvent uint8 I2CTargetEvent reflects events on the I2C bus
type NullSerial
type NullSerial struct { } NullSerial is a serial version of /dev/null (or null router): it drops everything that is written to it.
func (NullSerial) Buffered
func (ns NullSerial) Buffered() int Buffered returns how many bytes are buffered in the UART. It always returns 0 as there are no bytes to read.
func (NullSerial) Configure
func (ns NullSerial) Configure(config UARTConfig) error Configure does nothing: the null serial has no configuration.
func (NullSerial) ReadByte
func (ns NullSerial) ReadByte() (byte, error) ReadByte always returns an error because there aren’t any bytes to read.
func (NullSerial) Write
func (ns NullSerial) Write(p []byte) (n int, err error) Write is a no-op: none of the data is being written and it will not return an error.
func (NullSerial) WriteByte
func (ns NullSerial) WriteByte(b byte) error WriteByte is a no-op: the null serial doesn’t write bytes.
type PDMConfig
type PDMConfig struct { Stereobool DINPin CLKPin } type PWM
type PWM struct { PWM*nrf.PWM_Type channelValues[4]volatile.Register16 } PWM is one PWM peripheral, which consists of a counter and multiple output channels (that can be connected to actual pins). You can set the frequency using SetPeriod, but only for all the channels in this PWM peripheral at once.
func (*PWM) Channel
func (pwm *PWM) Channel(pin Pin) (uint8, error) Channel returns a PWM channel for the given pin.
func (*PWM) Configure
func (pwm *PWM) Configure(config PWMConfig) error Configure enables and configures this PWM. On the nRF52 series, the maximum period is around 0.26s.
func (*PWM) Set
func (pwm *PWM) Set(channel uint8, value uint32) Set updates the channel value. This is used to control the channel duty cycle. For example, to set it to a 25% duty cycle, use:
ch.Set(ch.Top() / 4) ch.Set(0) will set the output to low and ch.Set(ch.Top()) will set the output to high, assuming the output isn’t inverted.
func (*PWM) SetInverting
func (pwm *PWM) SetInverting(channel uint8, inverting bool) SetInverting sets whether to invert the output of this channel. Without inverting, a 25% duty cycle would mean the output is high for 25% of the time and low for the rest. Inverting flips the output as if a NOT gate was placed at the output, meaning that the output would be 25% low and 75% high with a duty cycle of 25%.
func (*PWM) SetPeriod
func (pwm *PWM) SetPeriod(period uint64) error SetPeriod updates the period of this PWM peripheral. To set a particular frequency, use the following formula:
period = 1e9 / frequency If you use a period of 0, a period that works well for LEDs will be picked.
SetPeriod will not change the prescaler, but also won’t change the current value in any of the channels. This means that you may need to update the value for the particular channel.
Note that you cannot pick any arbitrary period after the PWM peripheral has been configured. If you want to switch between frequencies, pick the lowest frequency (longest period) once when calling Configure and adjust the frequency here as needed.
func (*PWM) Top
func (pwm *PWM) Top() uint32 Top returns the current counter top, for use in duty cycle calculation. It will only change with a call to Configure or SetPeriod, otherwise it is constant.
The value returned here is hardware dependent. In general, it’s best to treat it as an opaque value that can be divided by some number and passed to pwm.Set (see pwm.Set for more information).
type PWMConfig
type PWMConfig struct { // PWM period in nanosecond. Leaving this zero will pick a reasonable period // value for use with LEDs. // If you want to configure a frequency instead of a period, you can use the // following formula to calculate a period from a frequency: // // period = 1e9 / frequency // Period uint64 } PWMConfig allows setting some configuration while configuring a PWM peripheral. A zero PWMConfig is ready to use for simple applications such as dimming LEDs.
type Pin
type Pin uint8 Pin is a single pin on a chip, which may be connected to other hardware devices. It can either be used directly as GPIO pin or it can be used in other peripherals like ADC, I2C, etc.
func (Pin) Configure
func (p Pin) Configure(config PinConfig) Configure this pin with the given configuration.
func (Pin) Get
func (p Pin) Get() bool Get returns the current value of a GPIO pin when the pin is configured as an input or as an output.
func (Pin) High
func (p Pin) High() High sets this GPIO pin to high, assuming it has been configured as an output pin. It is hardware dependent (and often undefined) what happens if you set a pin to high that is not configured as an output pin.
func (Pin) Low
func (p Pin) Low() Low sets this GPIO pin to low, assuming it has been configured as an output pin. It is hardware dependent (and often undefined) what happens if you set a pin to low that is not configured as an output pin.
func (Pin) PortMaskClear
func (p Pin) PortMaskClear() (*uint32, uint32) Return the register and mask to disable a given port. This can be used to implement bit-banged drivers.
func (Pin) PortMaskSet
func (p Pin) PortMaskSet() (*uint32, uint32) Return the register and mask to enable a given GPIO pin. This can be used to implement bit-banged drivers.
func (Pin) Set
func (p Pin) Set(high bool) Set the pin to high or low. Warning: only use this on an output pin!
func (Pin) SetInterrupt
func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) error SetInterrupt sets an interrupt to be executed when a particular pin changes state. The pin should already be configured as an input, including a pull up or down if no external pull is provided.
This call will replace a previously set callback on this pin. You can pass a nil func to unset the pin change interrupt. If you do so, the change parameter is ignored and can be set to any value (such as 0).
type PinChange
type PinChange uint8 type PinConfig
type PinConfig struct { Mode PinMode } type PinMode
type PinMode uint8 PinMode sets the direction and pull mode of the pin. For example, PinOutput sets the pin as an output and PinInputPullup sets the pin as an input with a pull-up.
type RingBuffer
type RingBuffer struct { rxbuffer[bufferSize]volatile.Register8 headvolatile.Register8 tailvolatile.Register8 } RingBuffer is ring buffer implementation inspired by post at https://www.embeddedrelated.com/showthread/comp.arch.embedded/77084-1.php
func (*RingBuffer) Clear
func (rb *RingBuffer) Clear() Clear resets the head and tail pointer to zero.
func (*RingBuffer) Get
func (rb *RingBuffer) Get() (byte, bool) Get returns a byte from the buffer. If the buffer is empty, the method will return a false as the second value.
func (*RingBuffer) Put
func (rb *RingBuffer) Put(val byte) bool Put stores a byte in the buffer. If the buffer is already full, the method will return false.
func (*RingBuffer) Used
func (rb *RingBuffer) Used() uint8 Used returns how many bytes in buffer have been used.
type SPI
type SPI struct { Bus*nrf.SPIM_Type buf*[1]byte// 1-byte buffer for the Transfer method } SPI on the NRF.
func (*SPI) Configure
func (spi *SPI) Configure(config SPIConfig) error Configure is intended to set up the SPI interface.
func (*SPI) Transfer
func (spi *SPI) Transfer(w byte) (byte, error) Transfer writes/reads a single byte using the SPI interface.
func (*SPI) Tx
func (spi *SPI) Tx(w, r []byte) error Tx handles read/write operation for SPI interface. Since SPI is a synchronous write/read interface, there must always be the same number of bytes written as bytes read. Therefore, if the number of bytes don’t match it will be padded until they fit: if len(w) > len(r) the extra bytes received will be dropped and if len(w) < len(r) extra 0 bytes will be sent.
type SPIConfig
type SPIConfig struct { Frequencyuint32 SCKPin SDOPin SDIPin LSBFirstbool Modeuint8 } SPIConfig is used to store config info for SPI.
type UART
type UART struct { Buffer *RingBuffer } UART on the NRF.
func (*UART) Buffered
func (uart *UART) Buffered() int Buffered returns the number of bytes currently stored in the RX buffer.
func (*UART) Configure
func (uart *UART) Configure(config UARTConfig) Configure the UART.
func (*UART) Read
func (uart *UART) Read(data []byte) (n int, err error) Read from the RX buffer.
func (*UART) ReadByte
func (uart *UART) ReadByte() (byte, error) ReadByte reads a single byte from the RX buffer. If there is no data in the buffer, returns an error.
func (*UART) Receive
func (uart *UART) Receive(data byte) Receive handles adding data to the UART’s data buffer. Usually called by the IRQ handler for a machine.
func (*UART) SetBaudRate
func (uart *UART) SetBaudRate(br uint32) SetBaudRate sets the communication speed for the UART.
func (*UART) Write
func (uart *UART) Write(data []byte) (n int, err error) Write data over the UART’s Tx. This function blocks until the data is finished being sent.
func (*UART) WriteByte
func (uart *UART) WriteByte(c byte) error WriteByte writes a byte of data over the UART’s Tx. This function blocks until the data is finished being sent.
type UARTConfig
type UARTConfig struct { BaudRateuint32 TXPin RXPin RTSPin CTSPin } UARTConfig is a struct with which a UART (or similar object) can be configured. The baud rate is usually respected, but TX and RX may be ignored depending on the chip and the type of object.
type UARTParity
type UARTParity uint8 UARTParity is the parity setting to be used for UART communication.