transmit 16bit values, add filtering and raw values

client/fetch.py

@@ -7,6 +7,9 @@ import time
 CUSTOM_RQ_ECHO = 0 # send back wValue and wIndex, for testing comms reliability
 CUSTOM_RQ_RESET = 1 # reset to bootloader
 CUSTOM_RQ_GET = 2 # get ldr value
+CUSTOM_RQ_RAW = 3 # get ldr value
+
+max_comm_retries = 5;
 
 def is_target_device(dev):
     if dev.manufacturer == "xythobuz.de" and dev.product == "AutoBrightness":
@@ -23,16 +26,27 @@ if dev is None:
 # configure the device
 dev.set_configuration()
 
-def read_u32(req, a=0, b=0):
-    r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, req, a, b, 4)
-    return int.from_bytes(r, "little")
+def read_val(req, w, a=0, b=0):
+    for attempts in range(0, max_comm_retries):
+        try:
+            r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, req, a, b, w)
+            return int.from_bytes(r, "little")
+        except usb.core.USBError as e:
+            if attempts >= (max_comm_retries - 1):
+                raise e
 
 # check for proper connectivity
-if read_u32(CUSTOM_RQ_ECHO, 42, 23) != (42 | (23 << 16)):
+if read_val(CUSTOM_RQ_ECHO, 4, 42, 23) != (42 | (23 << 16)):
     raise ValueError("invalid echo response")
 
 # repeatedly print value
 while True:
-    r = read_u32(CUSTOM_RQ_GET)
-    print(time.time(), ";", r, flush=True)
+    v = read_val(CUSTOM_RQ_GET, 2)
+    print(time.time(), ";", v, flush=True)
+
+    #r = read_val(CUSTOM_RQ_RAW, 2)
+    #print(time.time(), ";", r, flush=True)
+
+    #print(time.time(), ";", v, ";", r, flush=True)
+
     time.sleep(0.25)

sensor/include/adc.h

@@ -22,6 +22,7 @@
 #include <stdint.h>
 
 void adcInit(void);
-uint32_t adcGet(void);
+uint16_t adcGet(void);
+uint16_t adcRaw(void);
 
 #endif // __ADC_H__

sensor/reset.py

@@ -31,7 +31,7 @@ r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_RE
 print("reset-err", r)
 
 # value
-r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_GET, 0, 0, 4)
+r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_GET, 0, 0, 2)
 print("value", r)
 
 # reset ok

sensor/src/adc.c

@@ -22,17 +22,23 @@
 
 #include "adc.h"
 
-static uint32_t adc_value = 0;
+static int32_t adc_filter = 0;
+static uint16_t adc_prev = 0;
 
 void adcInit(void) {
     ADMUX = (1 << MUX0); // Vcc reference, ADC1 / PB2 in
     ADCSRA = (1 << ADEN) | (1 << ADIE) // adc and interrupt enabled
-            | (1 << ADPS2) | (1 << ADPS1) // prescaler 64
+            | (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0) // prescaler 128
             | (1 << ADSC); // start first conversion
 }
 
 static inline void adcFilter(uint16_t val) {
-    adc_value = val; // TODO
+    adc_prev = val;
+
+    int32_t input = val;
+    input <<= 16; // 10bit val --> 26bit input
+
+    adc_filter = adc_filter + ((input - adc_filter) >> 5);
 }
 
 ISR(ADC_vect) {
@@ -43,10 +49,18 @@ ISR(ADC_vect) {
     ADCSRA |= (1 << ADSC);
 }
 
-uint32_t adcGet(void) {
-    uint32_t val;
+uint16_t adcGet(void) {
+    uint16_t val;
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+        val = (adc_filter >> 16) + ((adc_filter & 0x00008000) >> 15);
+    }
+    return val;
+}
+
+uint16_t adcRaw(void) {
+    uint16_t val;
     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
-        val = adc_value;
+        val = adc_prev;
     }
     return val;
 }

sensor/src/usb.c

@@ -26,7 +26,8 @@
 
 #define CUSTOM_RQ_ECHO 0 // send back wValue and wIndex, for testing comms reliability
 #define CUSTOM_RQ_RESET 1 // reset to bootloader
-#define CUSTOM_RQ_GET 2 // get ldr value
+#define CUSTOM_RQ_GET 2 // get ldr value, filtered
+#define CUSTOM_RQ_RAW 3 // get raw ldr value
 
 usbMsgLen_t usbFunctionSetup(uchar data[8]) {
     usbRequest_t *rq = (void *)data;
@@ -52,15 +53,18 @@ usbMsgLen_t usbFunctionSetup(uchar data[8]) {
             dataBuffer[0] = 0; // error code
         }
         return 1;
-    } else if (rq->bRequest == CUSTOM_RQ_GET) {
-        uint32_t ldr_value = adcGet();
-        dataBuffer[0] = (ldr_value & 0x000000FF) >> 0;
-        dataBuffer[1] = (ldr_value & 0x0000FF00) >> 8;
-        dataBuffer[2] = (ldr_value & 0x00FF0000) >> 16;
-        dataBuffer[3] = (ldr_value & 0xFF000000) >> 24;
+    } else if ((rq->bRequest == CUSTOM_RQ_GET) || (rq->bRequest == CUSTOM_RQ_RAW)) {
+        uint16_t ldr_value;
+        if (rq->bRequest == CUSTOM_RQ_GET) {
+            ldr_value = adcGet();
+        } else {
+            ldr_value = adcRaw();
+        }
+        dataBuffer[0] = (ldr_value & 0x00FF) >> 0;
+        dataBuffer[1] = (ldr_value & 0xFF00) >> 8;
 
         usbMsgPtr = dataBuffer; // tell the driver which data to return
-        return 4; // tell the driver to send 4 bytes
+        return 2; // tell the driver to send 2 bytes
     }
 
     // default for not implemented requests: return no data back to host