pyupm_rn2903 module

class pyupm_rn2903.RN2903(*args)

Bases: object

API for the Microchip RN2903 LoRa radio.

ID: rn2903

Name: Microchip RN2903 LoRa radio

Category: wifi

Connection: uart The Microchip RN2903 Low-Power Long Range LoRa Technology Transceiver module provides an easy to use, low-power solution for long range wireless data transmission. The advanced command interface offers rapid time to market.

The RN2903 module complies with the LoRaWAN Class A protocol specifications. It integrates RF, a baseband controller, and a command Application Programming Interface (API) processor, making it a complete long range solution.

Most of the effort in this driver has been geared to supporting operation within a LoRaWAN network, however methods are provided to allow you to control the device directly so that you can implement whatever solution you require.

C++ includes: rn2903.hpp

autobaud(retries)

bool autobaud(int retries)

This function attempts to sync the device to the current baudrate. It tries retries times, to send an autobaud sequence to the device and run a test command.

retries: The number of times to retry autobaud detection

true if the test command succeeded, false otherwise

command(cmd)

RN2903_RESPONSE_T command(const std::string cmd)

Send a command, wait for a response using waitForResponse(), and return the status. The response itself will be stored internally, and can be retrieved using getResponse() and getResponseLen(). Every command will return at least one response, and this function will always wait for it and store it into the internal response buffer after sending the command.

cmd: A character string containing the command to send

One of the RN2903_RESPONSE_T values

commandWithArg(cmd, arg)

RN2903_RESPONSE_T commandWithArg(const std::string cmd, const std::string arg)

Build a command string with the supplied command and string argument. Then call command() with the result, and return the result. This is just a convenience function.

cmd: A character string containing the command to send

arg: A string argument for the command

One of the RN2903_RESPONSE_T values

dataAvailable(millis)

bool dataAvailable(unsigned int millis)

Determine whether there is data available to be read. This function will wait up to “millis” milliseconds for data to become available.

millis: The number of milliseconds to wait for data to become available.

true if data is available to be read, false otherwise.

drain()

void drain()

Read and throw away any data currently available to be read. This is useful to avoid reading data that might have been the result of a previous command interfering with data you currently want to read.

find(str)

bool find(const std::string str)

This is a utility function that can be used to indicate if a given string is present at the beginning of the response buffer. The search is case sensitive.

str: The string to search for

true if the string was found at the beginning of the response buffer, false otherwise

fromHex(src)

std::string fromHex(const std::string src)

Decode a hex byte string into the original string. The hex string must have a length that is a multiple of two, and all characters in the string must be valid hex characters.

A string containing the decoded contents of the hex string passed, or an empty string if there was an error.

getApplicationEUI()

void getApplicationEUI()

Retrieve the application EUI from the device. If this function succeeds, you can then use getResponse() to get the value.

std::runtime_error: if the mac get command failed

getApplicationKey()

void getApplicationKey()

Retrieve the application key from the device. If this function succeeds, you can then use rn2903_get_response() to get the value.

std::runtime_error: if the mac get command failed

getDeviceAddr()

void getDeviceAddr()

Retrieve the device address from the device. If this function succeeds, you can then use getResponse() to get the value.

std::runtime_error: if the mac get failed

getDeviceEUI()

void getDeviceEUI()

Retrieve the device EUI from the device. If this function succeeds, you can then use getResponse() to get the value.

UPM result

std::runtime_error: if the mac get command failed

getHardwareEUI()

std::string getHardwareEUI()

Return the Hardware Extended Unique Identifier (EUI). The is a 16 byte hex encoded string representing the 64b hardware EUI. This value cannot be changed, and is globally unique to each device. It is obtained from the device at initialization time.

A const string pointer to the hex encoded Hardware EUI

getMacStatus()

RN2903_MAC_STATUS_T getMacStatus()

Retrieve the MAC status. updateMacStatus() must have been called prior to calling this function. The MAC status is a bitfield embedded in the mac status word. It provides information on the status of the internal MAC state machine.

The MAC status, one of the RN2903_MAC_STATUS_T values.

getMacStatusWord()

int getMacStatusWord()

Retrieve the MAC status word. updateMacStatus() must have been called prior to calling this function.

The MAC status word. This is a bitmask of RN2903_MAC_STATUS_BITS_T bits.

getRadioRxPayload()

std::string getRadioRxPayload()

This is a utility function that can be used to return the hex encoded payload string for radio_rx messages received.

A string representing the hex encoded payload, or an empty string if there was an error

getResponse()

std::string getResponse()

Return a string containing a copy of the last response saved in the response buffer

A string containing a copy of the response buffer

getResponseLen()

int getResponseLen()

Return the length in bytes of the string containing the last response.

The length of the last response in bytes

join(type)

RN2903_JOIN_STATUS_T join(RN2903_JOIN_TYPE_T type)

Join a LoRaWAN network. There are two types of joins possible - Over The Air Activation (OTAA) and Activation by Personalization ( ABP). Each join method requires that certain items have been configured first.

For OTAA activation, the Device Extended Unique Identifier (EUI), the Application EUI, and Application Key must be set.

For ABP activation, The Device Address, Network Session Key, and the Application Session Key must be set.

type: The LoRaWAN join activation type, one of the RN2903_JOIN_TYPE_T values

The status of the join, one of the RN2903_JOIN_STATUS_T values

macPause()

void macPause()

Pause the MAC LoRaWAN stack. This device can operate in one of two modes.

The most common mode is used to join and participate in a LoRaWAN network as a Class A End Device. This is handled by the MAC LoRaWAN stack on the device dealing with the details of LoRaWAN participation automatically.

The other mode disables MAC LoRaWAN stack functionality and allows you to issue commands directly to the radio to set frequencies, data rates, modulation and many other parameters.

Calling this function disables the MAC LoRaWAN stack and allows you to issue radio commands that are otherwise handled automatically.

When pausing, the maximum allowable pause time in milliseconds will be returned in the response buffer. You can grab this value by calling getResponse() after this function completes successfully.

When the MAC is idle ( getMacStatus()), you can pause the stack indefinitely.

std::runtime_error: if the mac pause command failed

macResume()

void macResume()

Resume the MAC LoRaWAN stack. Call this to resume MAC LoRaWAN operation after having called macPause(), to resume participation in a LoRaWAN network.

dev: Device context

UPM result

std::runtime_error: if the mac resume command failed

macSave()

void macSave()

Save the configurable device values to EEPROM. These values will be reloaded automatically on a reset or power up.

The data that can be saved are: deveui, appeui, appkey, nwkskey (Network Session Key), appskey, devaddr, channels, upctr (Uplink Counter), dnctr (Downlink Counter), adr (automatic data-rate) state, and rx2 (the RX2 receive window parameters).

std::runtime_error: if the mac save command failed

macSetBattery(level)

void macSetBattery(int level)

LoRaWAN communications allows for the reporting of current battery charge remaining to the LoRaWAN gateway/network server. This function allows you to specify the value that should be reported.

The valid values are from 0 to 255. 0 = using external power 1(low) to 254(high) = battery power 255 = unable to measure battery level

level: The battery level value from 0-255

std::runtime_error: if the mac set bat command failed, or if the battery level is invalid

macTx(type, port, payload)

RN2903_MAC_TX_STATUS_T macTx(RN2903_MAC_MSG_TYPE_T type, int port, std::string payload)

Transmit a packet in a LoRaWAN network. You must already be joined to a LoRaWAN network for this command to succeed, and the MAC stack must be in the idle (RN2903_MAC_STAT_IDLE) state.

The packet payload must be a valid hex encoded string.

There is the possibility of receiving a downlink message after transmitting a packet. If this occurs, this function will return RN2903_MAC_TX_STATUS_RX_RECEIVED, and the returned data will be stored in the response buffer.

type: The type of message to send - confirmed or unconfirmed. One of the RN2903_MAC_MSG_TYPE_T values.

port: An integer in the range 1-223

payload: A valid hex encoded string that makes up the payload of the message

The status of the transmit request, one of the RN2903_MAC_TX_STATUS_T values

radioRx(window_size)

RN2903_RESPONSE_T radioRx(int window_size)

Receive a packet. This method uses the radio directly without the LoRaWAN stack running. For this reason, you must call macPause() before trying to receive using this function. You should also configure any parameters (frequency, etc) to match the transmitter before calling this function.

window_size: An integer that represents the number of symbols to wait for (lora) or the maximum number of milliseconds to wait (fsk). This parameter is passed to the “radio rx” command. Passing 0 causes the radio to enter continuous receive mode which will return when either a packet is received, or the radio watchdog timer expires. See the RN2903 Command Reference for details.

The status of the transmit request, one of the RN2903_RESPONSE_T values

radioTx(payload)

RN2903_RESPONSE_T radioTx(const std::string payload)

Transmit a packet. This method uses the radio directly without the LoRaWAN stack running. For this reason, you must call macPause() before trying to transmit using this function. You should also configure any radio parameters (frequency, etc), before calling this function.

payload: A valid hex encoded string that makes up the payload of the message

The status of the transmit request, one of the RN2903_RESPONSE_T values

reset()

void reset()

Reset the device. Any configuration is lost, as well as the current join status. This method also calls setBaudrate() after the reset to re-establish communications with the device in the event you are not using the default baudrate (which the device will revert to after a reset).

std::runtime_error: if the mac reset, or setBaudrate() command fails

setApplicationEUI(str)

void setApplicationEUI(const std::string str)

Set the MAC application EUI for LoRaWAN communications. The application EUI must be a hex encoded string of 16 bytes. This value must be set for LoRaWAN OTAA joining.

str: The 16-byte hex encoded application EUI

std::runtime_error: if the EUI is invalid, or if the mac set command failed

setApplicationKey(str)

void setApplicationKey(const std::string str)

Set the MAC application key for LoRaWAN communications. The application key must be a hex encoded string of 32 bytes. This value must be set for LoRaWAN OTAA joining.

str: The 32-byte hex encoded application key

std::runtime_error: if the key is invalid, or if the mac set command failed

setApplicationSessionKey(str)

void setApplicationSessionKey(std::string str)

Set the MAC application session key for LoRaWAN communications. The application session key must be a hex encoded string of 32 bytes. This value must be set for LoRaWAN ABP joining. It it not possible to retrieve this key.

For OTAA joining, this value will be overwritten once the join has completed, and therefore must not be set if performing an OTAA join.

str: The 32-byte hex encoded application session key

std::runtime_error: if the mac set command failed or the hex string is invalid

setBaudrate(baudrate)

void setBaudrate(unsigned int baudrate)

Set the baudrate of the device. Auto-bauding is currently only supported on Linux (due to the need to send a break signal) and only on a recent MRAA which supports it (> 1.6.1). If on a non-linux OS, you should not try to change the baudrate to anything other than the default 57600 or you will lose control of the device.

baudrate: The baud rate to set for the device

std::runtime_error: if the autobaud test command failed

setDebug(enable)

void setDebug(bool enable)

Enable debugging. If enabled, commands will be printed out before being sent to the device. Any responses will be printed out after retrieval. Other miscellaneous debug output will also be printed.

enable: true to enable debugging, false otherwise

setDeviceAddr(str)

void setDeviceAddr(std::string str)

Set the MAC device address for LoRaWAN communications. The device address must be a hex encoded string of 8 bytes. This value must be set for LoRaWAN ABP joining.

For OTAA joining, this value will be overwritten once the join has completed, and therefore must not be set if performing an OTAA join.

str: The 8-byte hex encoded device address

std::runtime_error: if the mac set command failed or the hex string is invalid

setDeviceEUI(str)

void setDeviceEUI(const std::string str)

Set the MAC device EUI for LoRaWAN communications. The device EUI must be a hex encoded string of 16 bytes. This value must be set for LoRaWAN OTAA joining.

str: The 16-byte hex encoded device EUI

std::runtime_error: if the EUI is invalid or the mac set command failed

setFlowControl(fc)

void setFlowControl(RN2903_FLOW_CONTROL_T fc)

Set a flow control method for the UART. By default, during initialization, flow control is disabled. The device MAY support hardware flow control, but MRAA does not (at least for UART numbers), so we can’t either. We leave the option here though so that if you are using a TTY (as opposed to a UART instance) it might work if the device is also configured to use hardware flow control.

fc: One of the RN2903_FLOW_CONTROL_T values

std::runtime_error: on failure

setNetworkSessionKey(str)

void setNetworkSessionKey(std::string str)

Set the MAC network session key for LoRaWAN communications. The network session key must be a hex encoded string of 32 bytes. This value must be set for LoRaWAN ABP joining. It it not possible to retrieve this key.

For OTAA joining, this value will be overwritten once the join has completed, and therefore must not be set if performing an OTAA join.

str: The 32-byte hex encoded network session key

std::runtime_error: if the mac set command failed or the hex string is invalid

setResponse2WaitTime(*args)

void setResponse2WaitTime(unsigned int wait_ms=RN2903_DEFAULT_RESP2_DELAY)

Set the default time, in milliseconds, to wait for the second response data to arrive. Some commands will have a second response emitted after the first response. This delay sets the maximum amount of time to wait for it.

wait_ms: The response delay to set, in milliseconds. The default is 60 seconds (60000ms).

setResponseWaitTime(*args)

void setResponseWaitTime(unsigned int wait_ms=RN2903_DEFAULT_RESP_DELAY)

Set the default time, in milliseconds, to wait for a response after sending a command. All commands return at least one response immediately after issuing the command. This delay sets the maximum amount of time to wait for it.

wait_ms: The response delay to set, in milliseconds. The default is 1 second (1000ms).

toHex(src)

std::string toHex(const std::string src)

Convert src into a hex byte string. All non-command related data such as keys, and payload sent to the device must be hex encoded.

src: A string to encode

A string containing the hex encoded version of str. In the event of an error, the return string will be empty.

updateMacStatus()

void updateMacStatus()

Retrieve the device MAC status, decode it, and store it internally. This function must be called prior to calling getMacStatusWord() or getMacStatus().

std::runtime_error: if the mac get command failed

waitForResponse(wait_ms)

RN2903_RESPONSE_T waitForResponse(int wait_ms)

Wait up to wait_ms milliseconds for a response.

In the case of errors (“invalid_param” received, timeout occurred, or other UPM specific error), this will be indicated by the return value.

Otherwise, an “ok” or other data value will not be considered an error and will return RN2903_RESPONSE_OK. The response itself will be stored internally, and can be retrieved using getResponse() and getResponseLen().

NOTE: the response buffer is overwritten whenever this function is called, so if there is data in there that you need to save, copy it somewhere else before calling any other methods in this driver to be safe.

wait_ms: The maximum number of milliseconds to wait for a response.

One of the RN2903_RESPONSE_T values