usb comms working. auto reset not.

sensor/49-autobrightness.rules

+# UDEV Rules for AutoBrightness modules.
+# This file must be placed at:
+#
+# /etc/udev/rules.d/49-autobrightness.rules    (preferred location)
+#   or
+# /lib/udev/rules.d/49-autobrightness.rules    (req'd on some broken systems)
+#
+# To install, type these commands in a terminal:
+#   sudo cp 49-autobrightness.rules /etc/udev/rules.d/49-autobrightness.rules
+#   sudo udevadm control --reload-rules
+#
+# After this file is copied, physically unplug and reconnect the board.
+#
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05dc", ATTRS{manufacturer}=="xythobuz.de", ATTRS{product}=="AutoBrightness", MODE:="0666"
+#
+# If you share your linux system with other users, or just don't like the
+# idea of write permission for everybody, you can replace MODE:="0666" with
+# OWNER:="yourusername" to create the device owned by you, or with
+# GROUP:="somegroupname" and mange access using standard unix groups.

sensor/Makefile

 	$(AVRDUDE) $(AVRDUDE_FLAGS) $(AVRDUDE_WRITE_FLASH) $(AVRDUDE_WRITE_EEPROM)
 
 
+upload: $(TARGET).hex
+	./flash.sh $(TARGET).hex
+
+
 # Generate avr-gdb config/init file which does the following:
 #     define the reset signal, load the target file, connect to target, and set 
 #     a breakpoint at main().

sensor/flash.sh

+#!/bin/bash
+
+# enter script directory
+cd "$(dirname "$0")"
+
+# upload to bootloader
+./micronucleus/commandline/builds/x86_64-linux-gnu/micronucleus $1

sensor/include/main.h

+/*
+ * main.h
+ *
+ * Copyright (c) 2024 Thomas Buck (thomas@xythobuz.de)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __MAIN_H__
+#define __MAIN_H__
+
+#include <stdbool.h>
+
+extern bool keep_feeding;
+
+#endif // __MAIN_H__

sensor/reset.py

+#!/usr/bin/env python
+
+import usb.core
+import usb.util
+
+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
+
+def is_target_device(dev):
+    if dev.manufacturer == "xythobuz.de" and dev.product == "AutoBrightness":
+        return True
+    return False
+
+# find our device
+dev = usb.core.find(idVendor=0x16c0, idProduct=0x05dc, custom_match=is_target_device)
+
+# was it found?
+if dev is None:
+    raise ValueError('Device not found')
+
+# configure the device
+dev.set_configuration()
+
+# echo
+r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_ECHO, 42, 23, 4)
+print("echo", r)
+
+# reset
+r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_RESET, 0, 0, 1)
+print("reset-err", r)
+
+# value
+r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_GET, 0, 0, 4)
+print("value", r)
+
+# reset ok
+r = dev.ctrl_transfer(usb.util.CTRL_TYPE_VENDOR | usb.util.CTRL_IN, CUSTOM_RQ_RESET, 42, 23, 1)
+print("reset-ok", r)

sensor/src/main.c

 
 #include "adc.h"
 #include "usbdrv.h"
+#include "main.h"
+
+bool keep_feeding = true;
 
 int __attribute__((noreturn)) main(void) {
     wdt_enable(WDTO_1S);
     // enable interrupts and enter main loop for USB polling
     sei();
     while (1) {
-        wdt_reset();
+        if (keep_feeding) {
+            wdt_reset();
+        }
+
         usbPoll();
     }
 }

sensor/src/usb.c

  * See <http://www.gnu.org/licenses/>.
  */
 
+#include <avr/wdt.h>
+
 #include "usbdrv.h"
 #include "osccal.c" // missing usbdrv include, so include here
 
+#include "main.h"
+
+#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
+
 usbMsgLen_t usbFunctionSetup(uchar data[8]) {
-    return 0;   /* default for not implemented requests: return no data back to host */
+    usbRequest_t *rq = (void *)data;
+    static uchar dataBuffer[4]; // buffer must stay valid when usbFunctionSetup returns
+
+    if (rq->bRequest == CUSTOM_RQ_ECHO) {
+        // echo -- used for reliability tests
+        dataBuffer[0] = rq->wValue.bytes[0];
+        dataBuffer[1] = rq->wValue.bytes[1];
+        dataBuffer[2] = rq->wIndex.bytes[0];
+        dataBuffer[3] = rq->wIndex.bytes[1];
+
+        usbMsgPtr = dataBuffer; // tell the driver which data to return
+        return 4; // tell the driver to send 4 bytes
+    } else if (rq->bRequest == CUSTOM_RQ_RESET) {
+        // check for proper keys
+        if ((rq->wValue.bytes[0] == 42) && (rq->wIndex.bytes[0] == 23)) {
+            keep_feeding = false; // watchdog will trigger in one interval
+            wdt_reset();
+
+            dataBuffer[0] = 42; // send confirmation
+        } else {
+            dataBuffer[0] = 0; // error code
+        }
+        return 1;
+    } else if (rq->bRequest == CUSTOM_RQ_GET) {
+        uint32_t ldr_value = 23; // TODO
+        dataBuffer[0] = (ldr_value & 0x000000FF) >> 0;
+        dataBuffer[1] = (ldr_value & 0x0000FF00) >> 8;
+        dataBuffer[2] = (ldr_value & 0x00FF0000) >> 16;
+        dataBuffer[3] = (ldr_value & 0xFF000000) >> 24;
+
+        usbMsgPtr = dataBuffer; // tell the driver which data to return
+        return 4; // tell the driver to send 4 bytes
+    }
+
+    // default for not implemented requests: return no data back to host
+    return 0;
 }