implement initial payload firmware and modem emulator

Makefile

@@ -15,7 +15,7 @@ OBJECTS = $(SOURCES:.cpp=.o)
 BINARY = blink.elf
 HEX = blink.hex
 
-all: $(HEX)
+all: #$(HEX)
 
 # compile .cpp files to .o
 .cpp.o:
@@ -29,6 +29,11 @@ $(BINARY): $(OBJECTS)
 $(HEX): $(BINARY)
 	$(OBJCOPY) $(HEXFLAGS) $< $@
 
+# symlinks this repo to the Arduino libraries directory so that its
+# code can be included in Arduino Sketches written in the IDE
+develop:
+	ln -s `pwd` $(ARDUINO_LIB_DIR)/TribeSat
+
 docker-build:
 	docker build -t firmware-builder .
 	docker run --rm -v `pwd`/:/firmware firmware-builder make

README.md

@@ -4,8 +4,25 @@
 
 Onboard software for TribeSat
 
-## Comm setup
+## Developing
 
-The communications sketches in the `src/TribeSatSerialPayload` and `src/TribeSatSerialModem` are an initial version of how to do communciations.
+Running `make develop` symlinks this repository to your Arduino libraries directory. Make sure to use the absolute path in the command below.
+
+```sh
+make develop ARDUINO_LIB_DIR=/Users/kelvin/Arduino/libraries
+```
+
+Now you can include the various components of the firmware in your Arduino code:
+
+```C++
+#include "Comms.h"
+#include "Packet.h"
+...
+```
+
+To set up hardware for developing and debugging, you can use 2 Arduinos; one acting as our payload and the other as the modem. One Uno pins 10 and 11 are cross-connected (10 to 11 for RX1/TX2, 11 to 10 for TX1/RX2) for serial communication. You can monitor the boards using the Arduino IDE serial monitor.
+
+## Tools
+
+The `/tools` directory contains an Arduino sketch `ModemEmulator` that makes turns an Arduino into an emulator of the onboard modem. It reads packets on serial and ACKs/NAKs them as appropriate.
 
-To develop this further, get two Arduino Uno's where pins 10 and 11 are cross-connected (10 to 11 for RX1/TX2, 11 to 10 for TX1/RX2). We use SoftwareSerial to connect using screen /dev/ttyACM0 57600 on the host computer end. Any screen input on the Payload side is turned into TribeSat ICD packets (1 char per packet) and transmitted to the Modem side where the entire packet is printed. The Modem side sends an ACK or NAK depending on whether the packet preamble is indeed HEX 50 50 50.

library.properties

@@ -0,0 +1,5 @@
+name=TribeSat
+version=0.0.1
+author=Kelvin Abrokwa
+maintainer=Kelvin Abrokwa
+category=Communication

src/Comms.cpp

@@ -0,0 +1,17 @@
+/**
+ *
+ */
+
+#include <Arduino.h>
+#include "Comms.h"
+#include "Packet.h"
+
+uint8_t PACKET_HEADER[3] = { 0x50, 0x50, 0x50 };
+uint8_t ACK[3] = { 0xAA, 0x05, 0x00 };
+uint8_t NAK[3] = { 0xAA, 0x05, 0xFF };
+
+//int sendPacket(Packet* packet) {}
+
+bool isACK(uint8_t* p) {
+    return p[2] == 0;
+}

src/Comms.h

@@ -0,0 +1,27 @@
+/**
+ *
+ */
+
+#ifndef COMMS_H
+#define COMMS_H
+
+#include <Arduino.h>
+#include "Packet.h"
+
+#define SEND_NUM_RETRIES 5
+
+extern uint8_t PACKET_HEADER[3];
+extern uint8_t ACK[3];
+extern uint8_t NAK[3];
+
+/**
+ *
+ */
+//int sendPacket(Packet* packet);
+
+/**
+ *
+ */
+bool isACK(uint8_t* p);
+
+#endif /* COMMS_H */

src/Packet.cpp

@@ -0,0 +1,98 @@
+/**
+ *
+ */
+#define DEBUG // TODO: REMOVE ME
+
+#include <Arduino.h>
+#include "Packet.h"
+
+/**
+ * Constructor with no packet
+ */
+Packet::Packet() {
+    this->header = this->packet; // header points to the top of the packet
+    this->data = this->packet + PACKET_HEADER_SIZE; // data is offset PACKET_HEADER_SIZE bytes
+}
+
+/**
+ * Destructor
+ */
+Packet::~Packet() {}
+
+#ifdef DEBUG
+/**
+ * Prints the packet to Serial
+ */
+void Packet::print() {
+    Serial.print("[Header = ");
+    for (int i = 0; i < PACKET_HEADER_SIZE; i++) {
+        Serial.print(this->header[i], HEX);
+        Serial.print(" ");
+    }
+
+    Serial.print(", Data = ");
+    for (int i = 0; i < PACKET_DATA_SIZE; i++) {
+        Serial.print(this->data[i], HEX);
+        Serial.print(" ");
+    }
+
+    Serial.println("]");
+
+    // Parse packet data and output individual fields
+    // temperature data
+    int temp = 0;
+    temp |= this->data[1];
+    temp <<= 8;
+    temp |= this->data[0];
+    Serial.print("Temperature: ");
+    Serial.println(temp);
+}
+#endif /* DEBUG */
+
+/**
+ *
+ */
+void Packet::setHeader(uint8_t* header) {
+    for (int i = 0; i < PACKET_HEADER_SIZE; i++)
+        this->header[i] = header[i];
+}
+
+/**
+ * Write to a specific byte in the packet data
+ */
+void Packet::setData(uint8_t byt, int index) {
+    this->data[index] = byt;
+}
+
+/**
+ * Copies the data
+ */
+void Packet::setData(uint8_t* data) {
+    for (int i = 0; i < PACKET_DATA_SIZE; i++)
+        this->data[i] = data[i];
+}
+
+/**
+ * Encode sensor data into the packet
+ */
+void Packet::setField(PacketField field, void* data) {
+    int temp;
+    switch (field) {
+        case Temperature:
+            temp = *((int*)data);
+            this->data[0] = temp & 0xff;
+            this->data[1] = (temp >> 8) & 0xff;
+            break;
+#ifdef DEBUG
+        default:
+            Serial.println("PACKET: invalid packet field");
+#endif /* DEBUG */
+    }
+}
+
+/**
+ * Returns a reference to the underlying array that is the packet
+ */
+uint8_t* Packet::toArray() {
+    return this->packet;
+}

src/Packet.h

@@ -0,0 +1,41 @@
+/**
+ *
+ */
+#define DEBUG // TODO: REMOVE ME
+
+#ifndef PACKET_H
+#define PACKET_H
+
+#include <Arduino.h>
+
+
+#define ACK_SIZE 3
+#define PACKET_HEADER_SIZE 3
+#define PACKET_DATA_SIZE 35
+#define PACKET_SIZE (PACKET_HEADER_SIZE + PACKET_DATA_SIZE)
+
+enum PacketField {
+    Temperature,
+};
+
+/**
+ * Packet data structure
+ */
+class Packet {
+  public:
+    Packet();
+    ~Packet();
+    void setHeader(uint8_t* header);
+    void setData(uint8_t byt, int index);
+    void setData(uint8_t* data);
+    void setField(PacketField field, void* data);
+    uint8_t* toArray();
+#ifdef DEBUG
+    void print();
+#endif /* DEBUG */
+  private:
+    uint8_t* header;
+    uint8_t* data;
+    uint8_t packet[PACKET_SIZE];
+};
+#endif /* PACKET_H */

src/Payload/Payload.ino

@@ -0,0 +1,148 @@
+/**
+ * Tribesat firmware entrypoint
+ */
+#include <SoftwareSerial.h>
+#include <Wire.h>
+#include "SparkFunTMP102.h"
+#include "Packet.h"
+#include "Comms.h"
+
+#define DEBUG
+
+SoftwareSerial ModemSerial(10, 11); // RX, TX
+
+uint8_t *ackOrNak = new uint8_t[ACK_SIZE];
+Packet *packet = new Packet();
+
+// For Adafruit TMP102
+const int TEMP_ALERT_PIN = A3;
+TMP102 tempSensor(0x48); // Initialize sensor at I2C address 0x48
+
+/**
+ *
+ */
+int readTempSensor() {
+  tempSensor.wakeup(); // turn sensor on
+  int temperature = (int)tempSensor.readTempC(); // read temperature data
+  tempSensor.sleep(); // put sensor in sleep mode
+  return temperature;
+}
+
+/**
+ *
+ */
+int sendPacket(Packet* packet) {
+  int retryCount = SEND_NUM_RETRIES;
+
+#ifdef DEBUG
+  Serial.print("sending packet: ");
+  packet->print();
+#endif /* DEBUG */
+
+  ModemSerial.write(packet->toArray(), PACKET_SIZE);
+
+  // read ACK or NAK - wait for 3 bytes to be written
+  while (ModemSerial.available() < ACK_SIZE)
+    delay(100);
+
+  for (int i = 0; i < ACK_SIZE; i++)
+    ackOrNak[i] = ModemSerial.read();
+
+  while (!isACK(ackOrNak) && retryCount) {
+    ModemSerial.write(packet->toArray(), PACKET_SIZE);
+
+    // read ACK or NAK - wait for 3 bytes to be written
+    while (ModemSerial.available() < ACK_SIZE)
+      delay(100);
+
+    for (int i = 0; i < ACK_SIZE; i++)
+      ackOrNak[i] = ModemSerial.read();
+
+    retryCount--;
+  }
+
+  if (isACK(ackOrNak)) {
+    return 1;
+  } else {
+#ifdef DEBUG
+    Serial.print("Failed to send packet after "); Serial.print(SEND_NUM_RETRIES); Serial.println(" attemps");
+#endif /* DEBUG */
+    return 0;
+  }
+}
+
+/**
+ * set up TMP102
+ */
+void initTempSensor() {
+  pinMode(TEMP_ALERT_PIN, INPUT);
+  tempSensor.begin();  // Join I2C bus
+
+  tempSensor.setFault(0);  // Trigger alarm immediately
+
+  // Initialize tempSensor settings
+  // These settings are saved in the sensor, even if it loses power
+
+  // set the number of consecutive faults before triggering alarm.
+  // 0-3: 0:1 fault, 1:2 faults, 2:4 faults, 3:6 faults.
+  tempSensor.setFault(0);  // Trigger alarm immediately
+
+  // set the polarity of the Alarm. (0:Active LOW, 1:Active HIGH).
+  tempSensor.setAlertPolarity(1); // Active HIGH
+
+  // set the sensor in Comparator Mode (0) or Interrupt Mode (1).
+  tempSensor.setAlertMode(0); // Comparator Mode.
+
+  // set the Conversion Rate (how quickly the sensor gets a new reading)
+  // 0-3: 0:0.25Hz, 1:1Hz, 2:4Hz, 3:8Hz
+  tempSensor.setConversionRate(2);
+
+  // set Extended Mode.
+  // 0:12-bit Temperature(-55C to +128C) 1:13-bit Temperature(-55C to +150C)
+  tempSensor.setExtendedMode(0);
+
+  // set T_HIGH, the upper limit to trigger the alert on
+  tempSensor.setHighTempC(29.4); // set T_HIGH in C
+
+  // set T_LOW, the lower limit to shut turn off the alert
+  tempSensor.setLowTempC(26.67); // set T_LOW in C
+
+#ifdef DEBUG
+  Serial.println("TEMP: Temperature sensor setup");
+#endif /* DEBUG */
+}
+
+/**
+ *
+ */
+void setup() {
+  // Open serial communications and wait for port to open:
+  Serial.begin(57600);
+
+  // set the data rate for the SoftwareSerial port
+  ModemSerial.begin(38400);
+
+  // all outgoing packets have the same header - write this once during setup
+  packet->setHeader(PACKET_HEADER);
+
+  // set up temperature sensor
+  initTempSensor();
+}
+
+/**
+ *
+ */
+void loop() {
+  // temperature
+  int temp = readTempSensor();
+  packet->setField(Temperature, &temp);
+  int success = sendPacket(packet);
+
+#ifdef DEBUG
+  if (success) {
+    Serial.println("Successfully sent packet");
+  } else {
+    Serial.println("Failed to send packet");
+  }
+#endif
+}