ank/ECE3849
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voltage scaling

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This commit is contained in:
Andy Killorin 2025-04-03 11:30:58 -04:00
parent 93c76775ca
commit 1ec0f63696
Signed by: ank
GPG key ID: 23F9463ECB67FE8C
1 changed files with 31 additions and 3 deletions
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34
main.c
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@ -35,6 +35,21 @@ volatile uint8_t drawRequested = 1;
#define WIDTH LCD_HORIZONTAL_MAX #define WIDTH LCD_HORIZONTAL_MAX
#define PIXELS_PER_DIV 20 #define PIXELS_PER_DIV 20
#define VIN_RANGE 3.3 // volts
#define ADC_BITS 12
#define ADC_OFFSET 30
#define VOLTAGE_SCALES 5
const char * const gVoltageScaleStr[VOLTAGE_SCALES] = {
"100 mV", "200 mV", "500 mV", " 1 V", " 2 V"
};
const float gVoltageScale[VOLTAGE_SCALES] = {
0.1, 0.2, 0.5, 1., 2.
};
int RisingTrigger(void);
// start a pwm test signal // start a pwm test signal
void start_signal() { void start_signal() {
// configure M0PWM2, at GPIO PF2, BoosterPack 1 header C1 pin 2 // configure M0PWM2, at GPIO PF2, BoosterPack 1 header C1 pin 2
@ -87,14 +102,22 @@ int main(void) {
ButtonInit(); ButtonInit();
IntMasterEnable(); IntMasterEnable();
uint8_t voltage_scale = 0;
while (true) { while (true) {
// handle buttons // handle buttons
Button button = (Button) 0; Button button = (Button) 0;
while (fifo_get(&button)) { while (fifo_get(&button)) {
switch (button) { switch (button) {
case S2: case S2: // draw
drawRequested = 1; drawRequested = 1;
break; break;
case Up: // next scale
voltage_scale = (voltage_scale + 1) % VOLTAGE_SCALES;
break;
case Down: // previous scale
voltage_scale = (voltage_scale + VOLTAGE_SCALES - 1) % VOLTAGE_SCALES;
break;
} }
} }
@ -130,9 +153,15 @@ int main(void) {
drawRequested = 0; drawRequested = 0;
} }
GrContextForegroundSet(&sContext, ClrWheat);
GrStringDraw(&sContext, gVoltageScaleStr[voltage_scale], /*length*/ -1, /*x*/ 0, /*y*/ 0, /*opaque*/ false);
float fVoltsPerDiv = gVoltageScale[voltage_scale];
float fScale = (VIN_RANGE * PIXELS_PER_DIV)/((1 << ADC_BITS) * fVoltsPerDiv);
GrContextForegroundSet(&sContext, ClrPink); GrContextForegroundSet(&sContext, ClrPink);
for(j=0; j<LOCAL_BUF_LEN; j++) { for(j=0; j<LOCAL_BUF_LEN; j++) {
#define TRANSPOSE(x) (HEIGHT/2) - (x >> 6) // reduce from twelve to six bits, then flip and center #define TRANSPOSE(x) (HEIGHT/2) - (int)roundf(fScale * ((int)x - ADC_OFFSET));
uint32_t upper,lower, current, last; uint32_t upper,lower, current, last;
if (j==0) { if (j==0) {
@ -191,7 +220,6 @@ int main(void) {
int RisingTrigger(void) // search for rising edge trigger int RisingTrigger(void) // search for rising edge trigger
{ {
#define ADC_OFFSET 20
int x = gADCBufferIndex - (WIDTH / 2); // half screen width int x = gADCBufferIndex - (WIDTH / 2); // half screen width
int x_stop = x - ADC_BUFFER_SIZE/2; int x_stop = x - ADC_BUFFER_SIZE/2;
for (; x > x_stop; x--) { for (; x > x_stop; x--) {