pxt-calliope/libs/radio/radio.cpp
2016-10-24 16:30:21 -07:00

380 lines
12 KiB
C++

#include "pxt.h"
using namespace pxt;
#define MAX_FIELD_NAME_LENGTH 12
#define MAX_PAYLOAD_LENGTH 20
#define PACKET_PREFIX_LENGTH 9
#define VALUE_PACKET_NAME_LEN_OFFSET 13
// Packet Spec:
// | 0 | 1 ... 4 | 5 ... 8 | 9 ... 28
// ----------------------------------------------------------------
// | packet type | system time | serial number | payload
//
// Serial number defaults to 0 unless enabled by user
// payload: number (9 ... 12)
#define PACKET_TYPE_NUMBER 0
// payload: number (9 ... 12), name length (13), name (14 ... 26)
#define PACKET_TYPE_VALUE 1
// payload: string length (9), string (10 ... 28)
#define PACKET_TYPE_STRING 2
//% color=270 weight=34
namespace radio {
// -------------------------------------------------------------------------
// Radio
// -------------------------------------------------------------------------
bool radioEnabled = false;
bool transmitSerialNumber = false;
PacketBuffer packet;
uint8_t type;
uint32_t time;
uint32_t serial;
int value;
StringData* msg;
int radioEnable() {
int r = uBit.radio.enable();
if (r != MICROBIT_OK) {
uBit.panic(43);
return r;
}
if (!radioEnabled) {
uBit.radio.setGroup(pxt::programHash());
radioEnabled = true;
}
return r;
}
void broadcastMessage(int message) {
if (radioEnable() != MICROBIT_OK) return;
uBit.radio.event.eventReceived(MicroBitEvent(MES_BROADCAST_GENERAL_ID, message, CREATE_ONLY));
}
void onBroadcastMessageReceived(int message, Action f) {
if (radioEnable() != MICROBIT_OK) return;
registerWithDal(MES_BROADCAST_GENERAL_ID, message, f);
}
void setPacketPrefix(uint8_t* buf, int type) {
// prefix: type (0), time (1..4), serial (5..8)
uint32_t t = system_timer_current_time();
uint32_t sn = transmitSerialNumber ? microbit_serial_number() : 0;
buf[0] = (uint8_t) type;
memcpy(buf + 1, &t, 4);
memcpy(buf + 5, &sn, 4);
}
uint8_t copyStringValue(uint8_t* buf, StringData* data, uint8_t maxLength) {
ManagedString s(data);
uint8_t len = min(maxLength, s.length());
// One byte for length of the string
buf[0] = len;
if (len > 0) {
memcpy(buf + 1, s.toCharArray(), len);
}
return len + 1;
}
StringData* getStringValue(uint8_t* buf, uint8_t maxLength) {
// First byte is the string length
uint8_t len = min(maxLength, buf[0]);
if (len) {
char name[maxLength + 1];
memcpy(name, buf + 1, len);
name[len] = 0;
return ManagedString(name).leakData();
}
return ManagedString().leakData();
}
/**
* Takes a packet from the micro:bit radio queue.
* @param writeToSerial if true, write the received packet to serial without updating the global packet;
if false, update the global packet instead
*/
void receivePacket(bool writeToSerial) {
PacketBuffer p = uBit.radio.datagram.recv();
uint8_t* buf = p.getBytes();
uint8_t tp;
int t;
int s;
int v;
StringData* m;
memcpy(&tp, buf, 1);
memcpy(&t, buf + 1, 4);
memcpy(&s, buf + 5, 4);
if (tp == PACKET_TYPE_STRING) {
v = 0;
m = getStringValue(buf + PACKET_PREFIX_LENGTH, MAX_PAYLOAD_LENGTH - 1);
}
else {
memcpy(&v, buf + 9, 4);
if (tp == PACKET_TYPE_VALUE) {
m = getStringValue(buf + VALUE_PACKET_NAME_LEN_OFFSET, MAX_FIELD_NAME_LENGTH);
}
else {
m = ManagedString().leakData();
}
}
if (!writeToSerial) {
// Refresh global packet
packet = p;
type = tp;
time = t;
serial = s;
value = v;
msg = m;
}
else {
// Convert the packet to JSON and send over serial
uBit.serial.send("{");
uBit.serial.send("\"t\":");
uBit.serial.send(t);
uBit.serial.send(",\"s\":");
uBit.serial.send(s);
if (tp == PACKET_TYPE_STRING || tp == PACKET_TYPE_VALUE) {
uBit.serial.send(",\"n\":\"");
uBit.serial.send(m);
uBit.serial.send("\"");
}
if (tp == PACKET_TYPE_NUMBER || tp == PACKET_TYPE_VALUE) {
uBit.serial.send(",\"v\":");
uBit.serial.send(v);
}
uBit.serial.send("}\r\n");
}
}
/**
* Broadcasts a number over radio to any connected micro:bit in the group.
*/
//% help=radio/send-number
//% weight=60
//% blockId=radio_datagram_send block="radio send number %value" blockGap=8
void sendNumber(int value) {
if (radioEnable() != MICROBIT_OK) return;
uint8_t length = PACKET_PREFIX_LENGTH + sizeof(uint32_t);
uint8_t buf[length];
memset(buf, 0, length);
setPacketPrefix(buf, PACKET_TYPE_NUMBER);
memcpy(buf + PACKET_PREFIX_LENGTH, &value, 4);
uBit.radio.datagram.send(buf, length);
}
/**
* Broadcasts a name / value pair along with the device serial number
* and running time to any connected micro:bit in the group.
* @param name the field name (max 12 characters), eg: "data"
* @param value the numberic value
*/
//% help=radio/send-value
//% weight=59
//% blockId=radio_datagram_send_value block="radio send|value %name|= %value" blockGap=8
void sendValue(StringData* name, int value) {
if (radioEnable() != MICROBIT_OK) return;
ManagedString n(name);
uint8_t buf[32];
memset(buf, 0, 32);
setPacketPrefix(buf, PACKET_TYPE_VALUE);
memcpy(buf + PACKET_PREFIX_LENGTH, &value, 4);
int stringLen = copyStringValue(buf + VALUE_PACKET_NAME_LEN_OFFSET, name, MAX_FIELD_NAME_LENGTH);
uBit.radio.datagram.send(buf, VALUE_PACKET_NAME_LEN_OFFSET + stringLen);
}
/**
* Broadcasts a string along with the device serial number
* and running time to any connected micro:bit in the group.
*/
//% help=radio/send-string
//% weight=58
//% blockId=radio_datagram_send_string block="radio send string %msg"
void sendString(StringData* msg) {
if (radioEnable() != MICROBIT_OK) return;
uint8_t buf[32];
memset(buf, 0, 32);
setPacketPrefix(buf, PACKET_TYPE_STRING);
int stringLen = copyStringValue(buf + PACKET_PREFIX_LENGTH, msg, MAX_PAYLOAD_LENGTH - 1);
uBit.radio.datagram.send(buf, PACKET_PREFIX_LENGTH + stringLen);
}
/**
* Reads the next packet from the radio queue and and writes it to serial
* as JSON.
*/
//% help=radio/write-value-to-serial
//% weight=3
//% blockId=radio_write_value_serial block="radio write value to serial"
//% advanced=true
void writeValueToSerial() {
if (radioEnable() != MICROBIT_OK) return;
receivePacket(true);
}
/**
* Reads the next packet from the radio queue and returns the packet's number
* payload or 0 if the packet did not contain a number.
*/
//% help=radio/receive-number
//% weight=46
//% blockId=radio_datagram_receive block="radio receive number" blockGap=8
//% deprecated=true
int receiveNumber()
{
if (radioEnable() != MICROBIT_OK) return 0;
receivePacket(false);
return value;
}
/**
* Registers code to run when a packet is received over radio.
*/
//% help=radio/on-data-received
//% weight=50
//% blockId=radio_datagram_received_event block="radio on data received" blockGap=8
//% deprecated=true
void onDataReceived(Action body) {
if (radioEnable() != MICROBIT_OK) return;
registerWithDal(MICROBIT_ID_RADIO, MICROBIT_RADIO_EVT_DATAGRAM, body);
// make sure the receive buffer has a free spot
receiveNumber();
}
/**
* Reads the next packet from the radio queue and returns the packet's string
* payload or the empty string if the packet did not contain a string.
*/
//% blockId=radio_datagram_receive_string block="radio receive string" blockGap=8
//% weight=44
//% help=radio/receive-string
//% deprecated=true
StringData* receiveString() {
if (radioEnable() != MICROBIT_OK) return ManagedString().leakData();
receivePacket(false);
return msg;
}
/**
* Gets the received signal strength indicator (RSSI) from the last packet taken
* from the radio queue (via ``receiveNumber``, ``receiveString``, etc). Not supported in simulator.
* namespace=radio
*/
//% help=radio/received-signal-strength
//% weight=40
//% blockId=radio_datagram_rssi block="radio received signal strength"
//% deprecated=true
int receivedSignalStrength() {
if (radioEnable() != MICROBIT_OK) return 0;
return packet.getRSSI();
}
/**
* Sets the group id for radio communications. A micro:bit can only listen to one group ID at any time.
* @ param id the group id between ``0`` and ``255``, 1 eg
*/
//% help=radio/set-group
//% weight=10 blockGap=8 advanced=true
//% blockId=radio_set_group block="radio set group %ID"
void setGroup(int id) {
if (radioEnable() != MICROBIT_OK) return;
uBit.radio.setGroup(id);
}
/**
* Change the output power level of the transmitter to the given value.
* @param power a value in the range 0..7, where 0 is the lowest power and 7 is the highest. eg: 7
*/
//% help=radio/set-transmit-power
//% weight=9 blockGap=8
//% blockId=radio_set_transmit_power block="radio set transmit power %power"
//% advanced=true
void setTransmitPower(int power) {
if (radioEnable() != MICROBIT_OK) return;
uBit.radio.setTransmitPower(power);
}
/**
* Set the radio to transmit the serial number in each message.
* @param transmit value indicating if the serial number is transmitted, eg: true
*/
//% help=radio/set-transmit-serial-number
//% weight=8 blockGap=8
//% blockId=radio_set_transmit_serial_number block="radio set transmit serial number %transmit"
//% advanced=true
void setTransmitSerialNumber(bool transmit) {
if (radioEnable() != MICROBIT_OK) return;
transmitSerialNumber = transmit;
}
/**
* Returns the number payload from the last packet taken from the radio queue
* (via ``receiveNumber``, ``receiveString``, etc) or 0 if that packet did not
* contain a number.
*/
//% help=radio/received-number
int receivedNumber() {
if (radioEnable() != MICROBIT_OK) return 0;
return value;
}
/**
* Returns the serial number of the sender micro:bit from the last packet taken
* from the radio queue (via ``receiveNumber``, ``receiveString``, etc) or 0 if
* that packet did not send a serial number.
*/
//% help=radio/received-serial
uint32_t receivedSerial() {
if (radioEnable() != MICROBIT_OK) return 0;
return serial;
}
/**
* Returns the string payload from the last packet taken from the radio queue
* (via ``receiveNumber``, ``receiveString``, etc) or the empty string if that
* packet did not contain a string.
*/
//% help=radio/received-string
StringData* receivedString() {
if (radioEnable() != MICROBIT_OK) return ManagedString().leakData();
return msg;
}
/**
* Returns the system time of the sender micro:bit at the moment when it sent the
* last packet taken from the radio queue (via ``receiveNumber``,
* ``receiveString``, etc).
*/
//% help=radio/received-time
uint32_t receivedTime() {
if (radioEnable() != MICROBIT_OK) return 0;
return time;
}
}