pre-alpha

Initial, uncalibrated values for basic gauges (no tach or mp).

Ready for thermocouple test.

README.md

@@ -84,7 +84,7 @@ Browse to 192.168.0.111, confirm Engiuno panel shows up.
 
 ### Arduino
 
-The Leonardo is rated to run from 6-20 volts although they suggest keeping it between 7-12 volts. They claim to worry about the voltage regulator overheating and 'damaging the board', but the regulator chip (88% efficient) does have a thermal shutdown feature at 150 deg C. The text appears to be a carry over from previous Arduino's which used a linear supply. **TBD** if heating is a problem. **TBD** if voltage sag during starting is a problem.
+The Leonardo is rated to run from 6-20 volts although they suggest keeping it between 7-12 volts. They claim to worry about the voltage regulator overheating and 'damaging the board', but the regulator chip (88% efficient) does have a thermal shutdown feature at 150 deg C. The text appears to be a carry over from previous Arduino's which used a linear supply. Typical power draw is 70mA for Arduino, no more than 90mA for pull ups, TBD for auxiliary display. **TBD** if heating is a problem. **TBD** if voltage sag during starting is a problem.
 
 The supply is rated for 1000 ma. The Leonardo uses 82 mA. Testing will need to be done to determine actual power used.
 
@@ -125,17 +125,17 @@ The main webpage has a timer running in Javascript on the tablet that invokes a
 
 ### Sensors
 
-The sensor system is fairly generic but currently only Van's Aircraft engine sensors have predefined configurations. The resistive sensors will have a 240 ohm(1%) pull up to Vcc. This will require up to 18 ma per sensor, or for the typical 5 sensors (fuel x 2, oil-p, oil-t, fuel-p) 90 ma total. This provides a good compromise between power usage, heat and loss of resolution. This provides 9 bits of resolution. To limit resistor heating to reasonable levels, .5 watt resistors should be used. Resistor temp. rise should be no more than 100 deg. C in free air. A resistance < 16 ohms will register as a short failure. > 480 ohms will register as an open failure. To convert from ADC units to ohms use this formula `ohms = 240 * (adc / (1024-adc))`, this will require long divided by long division unfortunately or a lookup/interpolation table.
+The sensor system is fairly generic but currently only Van's Aircraft engine sensors have predefined configurations. The resistive sensors will have a 240 ohm(1%) pull up to +5V. This will require up to 18 ma per sensor, or for the typical 5 sensors (fuel x 2, oil-p, oil-t, fuel-p) 90 ma total. This provides a good compromise between power usage, heat and loss of resolution. This provides 9 bits of resolution. To limit resistor heating to reasonable levels, .5 watt resistors should be used. Resistor temp. rise should be no more than 100 deg. C in free air. A resistance significantly out of range will mark the sensor inoperative. To convert from ADC units to ohms use this formula `ohms = 240 * (adc / (1024-adc))`, this will require long divided by long division unfortunately or a lookup/interpolation table.
 
-All but the oil-temp sensor are 33.5-240 ohm sensors. These usually scale linearly by resistance. Some may scale closer to ADC counts as follow: zero=240ohm/511adc, half=103ohm/716adc, full=33.5ohm/898adc. The oil temperature sensor (for a Rochester 3080-37) as follows (degF=ohms): 100=497, 150=179, 200=72, 250=34. This is a thermistor. Using a Steinhar-Hart calculator the conversion formula becomes `degrees Kelvin = 1 / (0.0016207535760566691 + 0.0002609330007304247 * log(R) + -1.0278556187396396e-7 * log(R)^3)`. A lookup table will certainly be required.
+All but the oil-temp sensor are 240-33.5 ohm sensors. These usually scale linearly by resistance. For those that don't, a custom interpolation table may be required. The oil temperature sensor (for a Rochester 3080-37) as follows (degF=ohms): 100=497, 150=179, 200=72, 250=34. This is a thermistor. Using a Steinhar-Hart calculator the conversion formula becomes `degrees Kelvin = 1 / (0.0016207535760566691 + 0.0002609330007304247 * log(R) + -1.0278556187396396e-7 * log(R)^3)`. An interpolation table is used to convert this.
 
-For resistive sensors still attached to the gauge, the gauge itself provides the pull up resistance and voltage. For Vans Aircraft engine instruments the pull up is 5 volts and the resistor is about 227 ohms(measured externally, internally the resistor appears to be 240 ohms, 5%). The pin can be directly connected if the voltage can't exceed Vcc by more than .5v. Otherwise a series resistor as discussed later could be attached to isolate the pin.
+For resistive sensors still attached to the gauge, the gauge itself provides the pull up resistance and voltage. For Vans Aircraft engine instruments the pull up is 5 volts and the resistor is about 227 ohms(measured externally, internally the resistor appears to be 240 ohms, 5%). The pin can be directly connected if the voltage can't exceed Vcc by more than .5v. Otherwise a 15K series resistor could be attached to help isolate the pin.
 
 For thermocouple sensors the board will detect both open and short. It directly reads out in degrees C (.25 resolution). This will optionally be converted to F. To support J style thermocouples, the C output will be adjusted by taking the thermocouple reading (before the CJT adjustment) `newC = oldC * 46677 / 65536`
 
 For the voltage sensor a 4:1 voltage divider consisting of a 1k and 3.01k (1%) resistor is used. This limits the draw to .1 watt at 20 volts or .05 at 14 volts.
 
-Typical sensors are Stewart Warner. The tachometer is supplied with 12 volts, a hall effect sensor that returns 5 volt pulses, 8/16 PPR, TBD. The manifold pressure sensor is believed to be 0-100mV ratio-metric.
+Typical sensors are Stewart Warner. The tachometer is supplied with 12 volts, a hall effect sensor that returns 5 volt pulses, 8/16 PPR, TBD. The manifold pressure sensor is believed to be 0-100mV ratio-metric. Either a better ADC (Adafruit ADS1015) will be needed or a new manifold pressure sensor.
 
 For a sensor that might contain a voltage higher than Vcc using a voltage divider as used on the voltage sensor will cause a significant load which could create issues if still attached to a backup gauge. Alternatively a 15K ohm resistor between the sensor and the pin will safely clip voltages between 20.5 and -15.5 volts. The goal here is to limit the internal clamping diodes to no more than 1ma after the .7 volt diode drop.
 
@@ -173,8 +173,7 @@ Other messages would include:
 * `Ot`
 * `FP`
 * `Cht`
-* `Shrt` short circuit, shown on second line
-* `OPEn` open circuit, shown on second line
+* `inoP` open or short circuit, shown on second line
 
 To prevent having to re-acknowledge warnings there would be both temporal and range hysteresis built in.
 
@@ -189,18 +188,21 @@ To prevent having to re-acknowledge warnings there would be both temporal and ra
 * 3K ohm 1% resistor - Digikey 3.01KXBK-ND
 * 1k ohm 1% resistor - Digikey 1.00KXBK-ND
 * 10 input screw terminal block - Digikey ED10567-ND
-* .025 square breakaway headers - Digikey 929647-04-35-ND - will probably work well on the thermocouple board w/o a header extension.
+* .025 square breakaway headers - Digikey 929834-04-36-ND (tin) or 929647-04-36-ND (gold) - will probably work well on the thermocouple board w/o a header extension.
 * jack for auxiliary display 6 pin - Digikey 455-2271-ND
 * header for auxiliary display 6 pin - Digikey 455-2218-ND
 * contacts for header x 10 - Digikey 455-1135-1-ND
 * pushbutton switch - Digikey EG2015-ND
 * K style thermocouple wire, 24-26 gauge, EBay
+* Bigger filter caps?, thermocouples Digikey 1276-1246-1-ND
+* Enclosure - Electrical box - B108R - Home Depot
 
 ### Future stuff
 * It may be possible to support 2 thermocouples without the thermocouple multiplexer shield by using the differential mode ADC, 40x gain and a thermistor. Only 8 bits are usable with 40x. 488 uV per count works out to 21.5 deg. F resolution with a K type thermocouple. The 2.56 volt internal reference would double the resolution and oversampling could probably double it again.
 * The Arduino Yun would support airplanes lacking a Stratux. The code would need to use the 'bridge' objects instead of the ethernet objects. Use #ifdef AVR_YUN to flex the code.
 * Themes - a dark theme could be created easily enough by adjusting the styles. A larger text theme for the gauges would involve more defines and stringizing them for the SVG.
 * Warning lights instead of auxillary display? A board with 4 caution/warning LEDs (red/green common cathode [bicolor LED]). Turning red and green on produces yellow. Alternatively use a module like the [BOB-13884] to provide 3 RGB LED's.
+* Create another TCP or UDP port that can be read from the Stratux (perhaps with netcat). This would be a comma separated text stream of engine data to be logged.
 * Use digitalFastWrite for smaller code - https://github.com/NicksonYap/digitalWriteFast
 * Create mult16x16to32 function for smaller code - https://github.com/rekka/avrmultiplication
 

enguino/config.h

@@ -8,7 +8,10 @@ const char *red = "red";
 #define MX(x) (int)((x)*(1<<divisor) + 0.5)
 #define GMX(range) (int)(1000.0 / (range) * (1<<divisor) + 0.5)
 #define GB(low) (int)(-((low) + 0.5)) 
-#define ADCtoV (5.0/1023.0) // multiply this by divider to get DC volts
+#define ADCtoDivV (5.0/1023.0) // multiply this by adc input to get DC volts
+#define ADCtoV10 (57 * ADCtoDivV) // Using 1:5.7 divider for now !!! 
+#define V10toADC (1/(57 * ADCtoDivV)) // Using 1:5.7 divider for now !!! 
+
 
 const int thermistorADC[] = {};
 const int thermistorC10[] = {};
@@ -25,14 +28,14 @@ const int resist240p1000[] = {};
 // Use GB() and GMX to set the graphs b and m values based on lowest input and input range (hi-low) respectively. 
 //
 const Sensor opS = { st_r240to33, 0, MX(0.1), 0, MX(1.0)}; // 0 - 100
-const Sensor otS = { st_r240to33,  50,  MX(0.2),  0, MX(1.0)}; // 50 - 250
-const Sensor vtS = { st_volts, 0, MX(ADCtoV*40),  0, 8008}; // 100 - 160 (10 - 16)
+const Sensor otS = { st_thermistor, 32, MX(1.8*.1), GB((50-32)*5./9.*10), GMX(200*10*5./9.)}; // 50 - 250
+const Sensor vtS = { st_volts, 0,  MX(ADCtoV10), GB(100*V10toADC), GMX(60*V10toADC)}; // 100 - 160 (10 - 16)
 const Sensor fpS = { st_r240to33, 0, MX(0.1), 0, MX(1.0)}; // 0 - 100 (0 - 10)
 const Sensor flS = { st_r240to33, 0, MX(0.16), 0, MX(1.0)}; // 0 - 160 (0 - 16)
 const Sensor taS = { st_tachometer, 0, 12000, 0, 8008 }; // 0 - 3000 
 const Sensor maS = { st_volts, 100, 2000, 0, 8008}; // 100 - 350 (10 - 35)
-const Sensor chS = { st_thermocouple, 32, MX(1.8/4), GB((100-32)*5./9.*4), GMX(400*5./9.*4)}; // 100 - 500, input is .25 C, convert to whole F 
-const Sensor egS = { st_thermocouple, 32, MX(1.8/4), GB((1000-32)*5./9.*4), GMX(600*5./9.*4)}; // 1000 - 1600,input is .25 C, convert to to whole F
+const Sensor chS = { st_k_type_tc,  32, MX(1.8/4), GB((100-32)*5./9.*4), GMX(400*5./9.*4)}; // 100 - 500, input is .25 C, convert to whole F 
+const Sensor egS = { st_k_type_tc,  32, MX(1.8/4), GB((1000-32)*5./9.*4), GMX(600*5./9.*4)}; // 1000 - 1600,input is .25 C, convert to to whole F
 
 // Labels
 // ------
@@ -79,9 +82,9 @@ int chRP[] = { 1000, 6000, 7940, 8000 };
 #define bank 3500 // bank of misc vertical gauges
 const Gauge gauges[] = {
  // x, y, style, decimal, label1, label2, units, labVal, labPt,num, regClr, regPt, num, sensor, pin
- {bank+0, 0, gs_vert, 0, "OIL", "PRES", "psi", opLV, opLP, N(opLV), opRC, opRP, N(opRC), &opS, 0},
- {bank+1750, 0, gs_vert, 0, "OIL", "TEMP", "&deg;F", otLV, otLP, N(otLV), otRC, otRP, N(otRC), &otS, 1},
- {bank+3500, 0, gs_vert, 1, "", "VOLT", "volt", vtLV, vtLP, N(vtLV), vtRC, vtRP, N(vtRC), &vtS, 2},
+ {bank+0, 0, gs_vert, 0, "OIL", "PRES", "psi", opLV, opLP, N(opLV), opRC, opRP, N(opRC), &opS, 1},
+ {bank+1750, 0, gs_vert, 0, "OIL", "TEMP", "&deg;F", otLV, otLP, N(otLV), otRC, otRP, N(otRC), &otS, 2},
+ {bank+3500, 0, gs_vert, 1, "", "VOLT", "volt", vtLV, vtLP, N(vtLV), vtRC, vtRP, N(vtRC), &vtS, 0},
  {bank+5250, 0, gs_vert, 1, "FUEL", "PRES", "psi", fpLV, fpLP, N(fpLV), fpRC, fpRP, N(fpRC), &fpS, 3},
  {bank+7000, 0, gs_pair, 1, "FUEL", "", "gal", flLV, flLP, N(flLV), flRC, flRP, N(flRC), &flS, 4}, // pins 4 and 5
  {100, 0, gs_round, 0, "TACH", "", "rpm", 0, 0, 0, taRC, taRP, N(taRC), &taS, -1},

enguino/egTypes.h

@@ -2,15 +2,25 @@
 
 #define N(x) sizeof(x)/sizeof(x[0])
 
+#define FAULT -32768
+
 typedef const char * string;
 
-enum SensorType {st_r240to33, st_thermistor, st_volts, st_thermocouple, st_tachometer, st_fuelflow};
+typedef struct {
+ int start;
+ byte n;
+ const byte *log2diff;
+ const int *result;
+} InterpolateTable;
+
+enum SensorType {st_r240to33, st_thermistor, st_volts, st_k_type_tc, st_j_type_tc, st_tachometer, st_fuel_flow};
 // st_r240to33 - 0 - 1000 proportional resistive sensor
 // st_thermistor - 0 - 1500 degrees C. in tenths
 // st_volts - 0 - 1023 ADC units 4.88 mV/per
-// st_thermocouple - 0 - 4000 0-1000 degrees C. in quarters
+// st_k_type_tc - 0 - 4000 0-1000 degrees C. in quarters
+// st_j_type_tc - 0 - 4000 0-1000 degrees C. in quarters
 // st_tachometer
-// st_fuelflow
+// st_fuel_flow
 
 // for K style in deg. C, use a multiply of 4096 (0.25), offset 0
 // for K style in deg. F, use a multiplier of 7373 (0.25 * 1.8), offset -32

enguino/enguino.ino

@@ -6,6 +6,8 @@
 // sketches don't like typdef's so they are in in this header file instead
 #include "egTypes.h"
 
+#include "utility.h"
+
 // configuration of sensors and layout of the gauges
 #include "config.h"
 
@@ -25,9 +27,7 @@ IPAddress ip(192, 168, 0, 111);
 EthernetServer server(80);
 EthernetClient client;
 
-int readPin(int p);
-
-#define FAULT -32768
+int readGauge(const Gauge *g, byte n = 0);
 
 // Performance 'print' functions to ethernet 'client' (includes flush)
 #include "printEthernet.h"
@@ -41,38 +41,68 @@ int readPin(int p);
 // Measure thermocouple tempertaures in the background
 #include "tcTemp.h"
 
-
-int readPin(int p) {
- if (p < 0)
- return FAULT;
-
- #ifdef RANDOM_SENSORS
+InterpolateTable thermistor = {
+ 64, 32,
+ (byte []) { 
+ 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5,
+ 5, 5, 5, 6, 6, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4 
+ },
+ (int []) { 
+ 1538, 1480, 1428, 1382, 1341, 1303, 1269, 1208,
+ 1154, 1107, 1064, 1026, 990, 957, 897, 844,
+ 796, 752, 711, 635, 564, 431, 363, 291,
+ 252, 210, 164, 112, 83, 50, 13, -30 
+ },
+};
+
+InterpolateTable r240to33 = {
+ 48, 28,
+ (byte []){ 
+ 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
+ },
+ (int []){ 
+ 1105, 1064, 1019, 972, 921, 894, 866,
+ 837, 806, 775, 742, 707, 671, 634,
+ 595, 553, 510, 465, 417, 367, 314,
+ 258, 199, 137, 70, 0, -75, -155
+ },
+ };
+
+int readGauge(const Gauge *g, byte n = 0) {
+ int p = g->pin + n;
 
+ #ifdef RANDOM_SENSORS
  if (p < 16)
  return rand() & 0x3ff; 
  if (p < 20) // CHT
  return rand() & 0x1ff;
- return rand() & 0x1ff + 1000; // EGT 
+ if (p < 24)
+ return rand() & 0x1ff + 1000; // EGT 
+ return FAULT;
 
  #else
-
- if (p < 16)
- return analogRead(p);
-
- noInterrupts();
- int t = tcTemp[p-16];
- interrupts();
- return t;
+ int v;
+ if (p < 0)
+ return FAULT;
 
+ if (p < 16) { 
+ v = analogRead(p);
+ int t = g->sensor->type;
+ if (t == st_r240to33)
+ v = interpolate(&r240to33, v);
+ else if (t == st_thermistor)
+ v = interpolate(&thermistor, v);
+ }
+ else if (p < 24) { 
+ noInterrupts();
+ v = tcTemp[p-16];
+ interrupts();
+ }
+ return v; 
  #endif
 }
 
-void logTime(unsigned long start, const char *description) {
- Serial.print(description);
- Serial.print(' ');
- Serial.print(int(millis()-start));
- Serial.print("ms\n");
-}
 
 void serveUpWebPage(char url) {
 // unsigned long start = millis(); 
@@ -92,14 +122,14 @@ void serveUpWebPage(char url) {
 
 
 void setup() {
-// Serial.begin(9600);
+ Serial.begin(9600);
 // while (!Serial) 
 // ; // wait for serial port to connect. Stops here until Serial Monitor is started. Good for debugging setup
 
  tcTempSetup();
  printLEDSetup();
  printLED(0,LED_TEXT(h,o,b,b));
- printLED(1,readPin(0),0); // replace this with a value read from EEPROM
+ printLED(1,1234,1); // replace this with a value read from EEPROM
  delay(1000); // replace this with LED self test sequence
 
  // start the Ethernet connection and the server:

enguino/printGauges.h

@@ -1,7 +1,7 @@
 /// Implementation for printPrefix and pringGauge
 
 int scaleMark(const Sensor *s, int val) {
- int mark = (int)(((long)s->mfactor * (long)val) >> divisor) + s->moffset;
+ int mark = int(multiply(s->mfactor, val+s->moffset) >> divisor);
  if (mark < 0)
  mark = 0;
  if (mark > 1000)
@@ -12,7 +12,7 @@ int scaleMark(const Sensor *s, int val) {
 int scaleValue(const Sensor *s, int val) {
  if (val == FAULT)
  return val;
- return (int)(((long)s->vfactor * (long)val) >> divisor) + s->voffset;
+ return int(multiply(s->vfactor,val) >> divisor) + s->voffset;
 }
 
 // vertical gauge is
@@ -22,7 +22,7 @@ void printVertical(const Gauge *g, bool showLabels) {
  // starts at 1100, 4000 high
  print_P(F("<rect x='400' y='1100' width='400' height='4000' class='rectgauge'/>\n"));
 
- int val = readPin(g->pin);
+ int val = readGauge(g);
  int mark = scaleMark(g->sensor, val) << 2;
 
  const char *color = 0;
@@ -99,7 +99,7 @@ void printHorizontal(const Gauge *g, int count) {
  print(600+offset);
  print_P(F("' width='8000' height='400' class='rectgauge'/>\n"));
 
- int val = readPin(g->pin + n);
+ int val = readGauge(g, n);
  int mark = scaleMark(g->sensor, val) << 3;
 
  const char *color = 0;
@@ -174,10 +174,10 @@ void printAuxHoriz(const Gauge *g, int count) {
  // starts at ..., 8000 wide
  int offset = 0;
  for (int n=0; n<count; n++) {
- int val = readPin(g->pin + n);
+ int val = readGauge(g, n);
  int mark = scaleMark(g->sensor, val) << 3;
-
- if (val == FAULT) {
+  
+  if (val == FAULT) {
  print_P(F("<rect x='9200' y='"));
  print(offset+550);
  print_P(F("' width='1000' height='500' rx='90' ry='90' fill='yellow'/>"));
@@ -277,7 +277,7 @@ void printRound(const Gauge *g) {
  print_P(F("<text x='0' y='5900' 700='unit'>"));
  print_text_close(g->units);
 
- int val = readPin(g->pin);
+ int val = readGauge(g);
  int mark = (scaleMark(g->sensor, val) * 24) / 10;
 
  int scale = scaleValue(g->sensor, val);