The final session of the Concept program (for now... we may build a LPF, TX and PA in the future) is the build of the SDR shield. The PCB for this shield is a little bit more complicated than the VFO and include one SMD to be mounted.
As mentioned in the last posting two toroid colds have to be wound:
These are a single coil of 37 turns on a T30-6 toroid (4.2uH) and a tri-filar coil of 10 turns on a T30-6 toroid (0.35uH).
Build sequence
The first component to mount is the FST3253 CMOS switch SMD device. Take a look back at the instructions in the VFO Build session to help with this step. Be sure to get the orientation of the part correct, pin 1 & 16 at the TOP.
Connect up and testing
Connect your LCD display and rotary encoder to the VFO shield, plug the SDR shield in above it and connect the audio cable to your PC or USB A-to-D convertor. Then connect an aerial to the RFbus pins RX and RXGND. Many users have preferred to use a larger display of 20 x 4 lines and the sketch below is for this display. Load and run it. Start the SDR program HDSDR on your PC and chose the correct sound put source. Then hit the START button and your SDR should be on the air!
Code
NOTE: not all LCD displays have the same I2C address, check your and change "0x27" in the code to your CLDs address (e.g. 0x3F is a common alternative).
// My_SDR_40M_4
// 20 x 4 display
// for 40m, with TX/RX control and bandplan display
// Si5351 I2C bus
// SDA = A4
// SCL = A5
// LCD I2C bus
// SDA = A4
// SCL = A5
// rotary encoder pins§ §§§
// DT = 2
// CLK = 3
// SW = 4
// I2C, Si5351, LCD and rotary Encoder libraries
#include "Wire.h"
#include "si5351.h"
#include "LiquidCrystal_I2C.h"
#include "Rotary.h"
// RTC I2C address
#define RTCADDR 0x68
// LCD
#define LCDADDR 0x27
#define LCDCOLS 20
#define LCDROWS 4
// rotary Encoder pins 2 & 3 (DT & CLK), step change pin 4 (SW)
#define DT 2
#define CLK 3
#define SW 4
// Rx & Tx signals
#define RX 13
#define TX 12
#define KEY 8
// number of band plans
#define PLANS 12
// dds object
Si5351 dds;
// LCD object
LiquidCrystal_I2C lcd(LCDADDR, LCDCOLS, LCDROWS);
// rotary Encoder object
Rotary rot = Rotary(DT, CLK);
// define plan structure
typedef struct {
uint32_t lower;
uint32_t upper;
char alloc[30];
} plan;
// band plan array contents cHz/cHz/Text
plan bp[PLANS] = {
{700000000, 700100000, "CW QRSS 7000.7 "},
{700100000, 703990000, "CW PSK31 QRP 7030"},
{703990000, 704690000, "NB WSPR 7040 "},
{704600000, 704990000, "NB Auto "},
{704990000, 705290000, "All Auto "},
{705290000, 705990000, "All Digital "},
{705990000, 706990000, "All "},
{706990000, 707990000, "All HELL 7077 "},
{707990000, 709990000, "All SSB QRP 7090 "},
{709990000, 712990000, "All EMGCY 7110 "},
{712990000, 717490000, "All SSB CON 7165 "},
{717490000, 720010000, "All DX Intnl "},
};
// start freq & step
uint32_t freq = 700000000; // cHz, start frequency
uint32_t step = 10000; // cHz, init 100Hz step
// RTC time and date
byte Second, prevSecond, Minute, Hour, DoW, Date, prevDate, Month, Year;
void setup() {
// init LCD & backlight on
lcd.init();
lcd.backlight();
// init dds si5351 module, "0" = default 25MHz XTAL
dds.init(SI5351_CRYSTAL_LOAD_8PF, 0);
// set 8mA output drive (max possible)
dds.drive_strength(SI5351_CLK2, SI5351_DRIVE_8MA);
// can insert Si5351 calibration here if required
// enable SDR output CLK2, disable CLK0 & 1
dds.output_enable(SI5351_CLK0, 0);
dds.output_enable(SI5351_CLK1, 0);
dds.output_enable(SI5351_CLK2, 1);
// encoder, button, RX, TX, band and KEY pins
pinMode(DT, INPUT_PULLUP);
pinMode(CLK, INPUT_PULLUP);
pinMode(SW, INPUT_PULLUP);
pinMode(RX, OUTPUT);
pinMode(TX, OUTPUT);
pinMode(KEY, INPUT_PULLUP);
xmit(digitalRead(KEY)); // set RX|TX, KEY = LOW is TX
getRTC(); // get time
freqOut(freq); // cHz, output freq
dispDate(0, 0);
dispTime(12, 0);
dispFreq(6, 2, freq, 1); // display freq kHz col 4 row 2
dispMsg(0, 3, scanPlan()); // display band plan col 0 row 3
}
void loop() {
getRTC(); // get time
if (Date != prevDate) {
dispDate(0, 0);
prevDate = Date;
}
if (Second != prevSecond) {
dispTime(12, 0); // display it, if changed
prevSecond = Second;
}
// tune?
if (tune()) {
freqOut(freq); // output freq
dispFreq(6, 2, freq, 1); // update freq display
dispMsg(0, 3, scanPlan()); // update band plan display
}
// step?
if (button()) {
dispStep(step, 17, 2);
}
xmit(digitalRead(KEY)); // RX|TX
}
// tune?
bool tune() {
unsigned char dir; // tuning direction CW/CCW
dir = rot.process(); // read encoder
if (dir != DIR_NONE) { // turned?
if (dir == DIR_CW && (freq < bp[PLANS - 1].upper - step)) freq += step;
if (dir == DIR_CCW && (freq >= bp[0].lower + step)) freq -= step;
return true;
}
return false;
}
// change step?
bool button() {
if (digitalRead(SW) == LOW) { // button pressed?
while (!digitalRead(SW)); // wait for release
if (step == 1000000) step = 10000; // reset
else step = step * 10; // or increment by x10
return true;
}
return false;
}
// search for band info
char *scanPlan() {
for (int i = 0; i < 15; i++) {
if (freq >= bp[i].lower && freq < bp[i].upper) // find plan
return bp[i].alloc; // return when found
}
}
// Output Freq for SDR, on CLK2, f cHz
void freqOut(uint32_t f) {
dds.set_freq(f * 4ULL, 0ULL, SI5351_CLK2);
}
// Tx/Rx KEY HIGH = RX, LOW = TX
void xmit(bool x)
{
if (x == LOW) // TX
{
dispMsg(0, 2, "TX ");
digitalWrite(RX, HIGH); // Rx off
digitalWrite(TX, LOW); // Tx on
}
else
{
dispMsg(0, 2, "SDR");
digitalWrite(RX, LOW); // Rx on
digitalWrite(TX, HIGH); // Tx off
}
}
// display char msg at col c, row r
void dispMsg(uint8_t c, uint8_t r, char *m) {
lcd.setCursor(c, r);
lcd.print(m);
}
// get time from RTC, convert bcd to decimal
void getRTC() {
// Reset the RTC register pointer
Wire.beginTransmission(RTCADDR);
byte zero = 0x00;
Wire.write(zero);
Wire.endTransmission();
// request 7 bytes from the RTC address
Wire.requestFrom(RTCADDR, 7);
// get the time data
Second = bcdToDec(Wire.read()); // 0 - 59
Minute = bcdToDec(Wire.read()); // 0 - 59
Hour = bcdToDec(Wire.read() & 0b111111); // mask 12/24 bit
DoW = bcdToDec(Wire.read()); //0 - 6 = Sunday - Saturday
Date = bcdToDec(Wire.read()); // 1 - 31
Month = bcdToDec(Wire.read()); // 0 = jan
Year = bcdToDec(Wire.read()); // 20xx
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val) {
return ( (val / 16 * 10) + (val % 16) );
}
// display freq in kHz at col c, row r, f cHz, d decimal places
void dispFreq(uint8_t c, uint8_t r, uint32_t f, uint8_t d) {
lcd.setCursor(c, r);
lcd.print((float)f / 100000, d); // convert to float & kHz
lcd.print("kHz ");
}
// display step
void dispStep(uint32_t s, byte c, byte r)
{
switch (s) // display step
{
case 10000:
dispMsg(c, r, " ");
break;
case 100000:
dispMsg(c, r, " +");
break;
case 1000000:
dispMsg(c, r, "++");
break;
}
}
// display date and time
void dispDate(byte c, byte r) {
lcd.setCursor(c, r);
switch (DoW) {
case 1:
lcd.print("Mon");
break;
case 2:
lcd.print("Tue");
break;
case 3:
lcd.print("Wed");
break;
case 4:
lcd.print("Thu");
break;
case 5:
lcd.print("Fri");
break;
case 6:
lcd.print("Sat");
break;
case 7:
lcd.print("Sun");
break;
}
lcd.print(" ");
lcd.print(Date);
lcd.print(" ");
switch (Month)
{
case 1:
lcd.print("Jan");
break;
case 2:
lcd.print("Feb");
break;
case 3:
lcd.print("Mar");
break;
case 4:
lcd.print("Apr");
break;
case 5:
lcd.print("May");
break;
case 6:
lcd.print("Jun");
break;
case 7:
lcd.print("Jul");
break;
case 8:
lcd.print("Aug");
break;
case 9:
lcd.print("Sep");
break;
case 10:
lcd.print("Oct");
break;
case 11:
lcd.print("Nov");
break;
case 12:
lcd.print("Dec");
break;
}
}
void dispTime(byte c, byte r) {
lcd.setCursor(c, r);
if (Hour < 10)
lcd.print("0");
lcd.print(Hour);
lcd.print(":");
if (Minute < 10)
lcd.print("0");
lcd.print(Minute);
lcd.print(":");
if (Second < 10)
lcd.print("0");
lcd.print(Second);
}
No comments:
Post a Comment