allow setting sensitivity

firmware/include/config.h

+/*
+ * config.h
+ */
+
+#ifndef __CONFIG_H__
+#define __CONFIG_H__
+
+#define PMW_MOTION_PIN 20
+
+#define PMW_PRINT_IDS
+#define PMW_IRQ_COUNTERS
+//#define PMW_FEATURE_WIRELESS
+//#define DISABLE_CDC_DTR_CHECK
+
+#endif // __CONFIG_H__

firmware/include/pmw3360.h

 
 int pmw_init(void);
 
-void print_pmw_status(void);
+/*
+ * 0x00: 100 cpi (minimum cpi)
+ * 0x01: 200 cpi
+ * 0x02: 300 cpi
+ * ...
+ * 0x31: 5000 cpi (default cpi)
+ * ...
+ * 0x77: 12000 cpi (maximum cpi)
+ */
+void pmw_set_sensitivity(uint8_t sens);
+uint8_t pmw_get_sensitivity(void);
+#define PMW_SENSE_TO_CPI(sense) (100 + (sense * 100))
+
+void pmw_print_status(void);
 
 #endif // __PMW3360_H__

firmware/include/util.h

 void heartbeat_init(void);
 void heartbeat_run(void);
 
+bool str_startswith(const char *str, const char *start);
+
 void reset_to_bootloader(void);
 
 #endif // __UTIL_H__

firmware/src/console.c

  * console.c
  */
 
+#include <inttypes.h>
 #include <string.h>
 #include "pico/stdlib.h"
+
+#include "config.h"
 #include "log.h"
 #include "pmw3360.h"
+#include "util.h"
 #include "console.h"
 
 #define CNSL_BUFF_SIZE 1024
             || (strcmp(line, "h") == 0)
             || (strcmp(line, "?") == 0)) {
         print("Trackball Firmware Usage:");
-        print("    help - print this message");
-        print("     pmw - print PMW3360 status");
-        print("    \\x18 - reset to bootloader");
+        print("    cpi - print current sensitivity");
+        print("  cpi N - set sensitivity");
+        print("    pmw - print PMW3360 status");
+        print("   help - print this message");
+        print("   \\x18 - reset to bootloader");
     } else if (strcmp(line, "pmw") == 0) {
-        print_pmw_status();
+        pmw_print_status();
+    } else if (strcmp(line, "cpi") == 0) {
+        uint8_t sense = pmw_get_sensitivity();
+        uint16_t cpi = PMW_SENSE_TO_CPI(sense);
+        print("current cpi: %u (0x%02X)", cpi, sense);
+    } else if (str_startswith(line, "cpi ")) {
+        const char *num_str = line + 4;
+        uintmax_t num = strtoumax(num_str, NULL, 10);
+        if ((num < 100) || (num > 12000)) {
+            print("invalid cpi %llu, needs to be %u <= cpi <= %u", num, 100, 12000);
+        } else {
+            num /= 100;
+            num -= 1;
+            print("setting cpi to 0x%02llX", num);
+            pmw_set_sensitivity(num);
+        }
     } else {
         print("unknown command \"%s\"", line);
     }

firmware/src/log.c

 #include <stdarg.h>
 #include <stdio.h>
 #include "pico/stdlib.h"
+
+#include "config.h"
 #include "usb_cdc.h"
 #include "log.h"
 

firmware/src/main.c

 
 #include "pico/stdlib.h"
 
+#include "config.h"
 #include "util.h"
 #include "console.h"
 #include "log.h"

firmware/src/pmw3360.c

 #include "pico/binary_info.h"
 #include "hardware/spi.h"
 
-#define PMW_PRINT_IDS
-#define PMW_IRQ_COUNTERS
-//#define PMW_FEATURE_WIRELESS
-
+#include "config.h"
 #include "log.h"
 #include "pmw3360_registers.h"
 #include "pmw3360_srom.h"
 #error PMW3360 API requires a board with SPI pins
 #endif
 
-#define PMW_MOTION_PIN 20
-
 #ifdef PMW_IRQ_COUNTERS
 static uint64_t pmw_irq_count_all = 0;
 static uint64_t pmw_irq_count_motion = 0;
 static uint64_t pmw_irq_count_rest3 = 0;
 #endif // PMW_IRQ_COUNTERS
 
-void print_pmw_status(void) {
+void pmw_print_status(void) {
 #ifdef PMW_IRQ_COUNTERS
     print("    pmw_irq_cnt_all = %llu", pmw_irq_count_all);
     print(" pmw_irq_cnt_motion = %llu", pmw_irq_count_motion);
     }
 }
 
+void pmw_set_sensitivity(uint8_t sens) {
+    if (sens > 0x77) {
+        debug("invalid sense, clamping (0x%X > 0x77)", sens);
+        sens = 0x77;
+    }
+
+    pmw_write_register(REG_CONFIG1, sens);
+    pmw_write_register(REG_CONFIG5, sens);
+}
+
+uint8_t pmw_get_sensitivity(void) {
+    uint8_t sense_y = pmw_read_register(REG_CONFIG1);
+    uint8_t sense_x = pmw_read_register(REG_CONFIG5);
+    if (sense_y != sense_x) {
+        debug("sensitivity differs for x (0x%02X) and y (0x%02X). resetting.", sense_x, sense_y);
+        pmw_write_register(REG_CONFIG5, sense_y);
+    }
+    return sense_y;
+}
+
 int pmw_init(void) {
     pmw_spi_init();
 
     pmw_write_register(REG_CONFIG2, 0x00);
 #endif // PMW_FEATURE_WIRELESS
 
+    // Set sensitivity for each axis
+    pmw_write_register(REG_CONFIG2, pmw_read_register(REG_CONFIG2) | 0x04);
+    pmw_set_sensitivity(0x31); // default: 5000cpi
+
     // setup MOTION pin interrupt to handle reading data
     gpio_add_raw_irq_handler(PMW_MOTION_PIN, pmw_motion_irq);
     gpio_set_irq_enabled(PMW_MOTION_PIN, GPIO_IRQ_EDGE_FALL, true);

firmware/src/usb.c

 #include "bsp/board.h"
 #include "tusb.h"
 
+#include "config.h"
 #include "usb_descriptors.h"
 #include "usb_cdc.h"
 #include "usb_hid.h"

firmware/src/usb_cdc.c

 #include "bsp/board.h"
 #include "tusb.h"
 
+#include "config.h"
 #include "console.h"
 #include "log.h"
 #include "util.h"

firmware/src/usb_descriptors.c

 
 #include "pico/unique_id.h"
 #include "tusb.h"
+
+#include "config.h"
 #include "usb_descriptors.h"
 
 /*

firmware/src/usb_hid.c

 #include "bsp/board.h"
 #include "tusb.h"
 
+#include "config.h"
 #include "usb_descriptors.h"
 #include "usb_hid.h"
 
         case REPORT_ID_MOUSE:
         {
             // no button, right + down, no scroll, no pan
-            tud_hid_mouse_report(REPORT_ID_MOUSE, 0x00, delta_x, delta_y, 0, 0);
+            tud_hid_mouse_report(REPORT_ID_MOUSE, 0x00, -delta_x, -delta_y, 0, 0);
 
             // TODO
             delta_x = 0;

firmware/src/util.c

  * util.c
  */
 
+#include <string.h>
 #include "pico/stdlib.h"
 #include "pico/bootrom.h"
+
+#include "config.h"
 #include "util.h"
 
 #define HEARTBEAT_INTERVAL_MS 500
 #endif // PICO_DEFAULT_LED_PIN
 }
 
+bool str_startswith(const char *str, const char *start) {
+    size_t l = strlen(start);
+    if (l > strlen(str)) {
+        return false;
+    }
+    return (strncmp(str, start, l) == 0);
+}
+
 void reset_to_bootloader(void) {
 #ifdef PICO_DEFAULT_LED_PIN
     reset_usb_boot(1 << PICO_DEFAULT_LED_PIN, 0);