Merge pull request #114 from davidgiven/fixing1

Add support for measuring signal line voltages.

FluxEngine.cydsn/main.c

@@ -99,6 +99,15 @@ static void start_motor(void)
     CyWdtClear();
 }
 
+static void stop_motor(void)
+{
+    if (motor_on)
+    {
+        MOTOR_REG_Write(0);
+        motor_on = false;
+    }
+}
+
 static void wait_until_writeable(int ep)
 {
     while (USBFS_GetEPState(ep) != USBFS_IN_BUFFER_EMPTY)
@@ -138,25 +147,36 @@ static void cmd_get_version(struct any_frame* f)
 
 static void step(int dir)
 {
-    STEP_REG_Write(dir);
-    CyDelayUs(1);
-    STEP_REG_Write(dir | 2);
-    CyDelayUs(1);
-    STEP_REG_Write(dir);
+    STEP_REG_Write(dir); /* step high */
+    CyDelayUs(6);
+    STEP_REG_Write(dir | 2); /* step low */
+    CyDelayUs(6);
+    STEP_REG_Write(dir); /* step high again, drive moves now */
     CyDelay(STEP_INTERVAL_TIME);
 }
 
+static void home(void)
+{
+    for (int i=0; i<100; i++)
+    {
+        /* Don't keep stepping forever, because if a drive's
+         * not connected bad things happen. */
+        if (TRACK0_REG_Read())
+            break;
+        step(STEP_TOWARDS0);
+    }
+
+    /* Step to -1, which should be a nop, to reset the disk on disk change. */
+    step(STEP_TOWARDS0);
+}
+
 static void seek_to(int track)
 {
     start_motor();
-    if (!homed)
+    if (!homed || (track == 0))
     {
         print("homing");
-        while (!TRACK0_REG_Read())
-            step(STEP_TOWARDS0);
-
-        /* Step to -1, which should be a nop, to reset the disk on disk change. */
-        step(STEP_TOWARDS0);
+        home();
 
         homed = true;
         current_track = 0;
@@ -167,11 +187,7 @@ static void seek_to(int track)
     while (track != current_track)
     {
         if (TRACK0_REG_Read())
-        {
-            if (current_track != 0)
-                print("unexpectedly detected track 0");
             current_track = 0;
-        }
 
         if (track > current_track)
         {
@@ -606,19 +622,113 @@ static void cmd_erase(struct erase_frame* f)
     send_reply((struct any_frame*) &r);
 }
 
-static void cmd_set_drive(struct set_drive_frame* f)
+static void set_drive_flags(uint8_t flags)
 {
-    if (current_drive_flags != f->drive_flags)
-    {
-        current_drive_flags = f->drive_flags;
-        DRIVE_REG_Write(current_drive_flags);
+    if (current_drive_flags != flags)
         homed = false;
-    }
+
+    current_drive_flags = flags;
+    DRIVESELECT_REG_Write((flags & 1) ? 2 : 1); /* select drive 1 or 0 */
+    DENSITY_REG_Write(flags >> 1); /* density bit */
+}
+
+static void cmd_set_drive(struct set_drive_frame* f)
+{
+    set_drive_flags(f->drive_flags);
 
     DECLARE_REPLY_FRAME(struct any_frame, F_FRAME_SET_DRIVE_REPLY);
     send_reply((struct any_frame*) &r);
 }
-
+
+static uint16_t read_output_voltage_mv(void)
+{
+    OUTPUT_VOLTAGE_ADC_StartConvert();
+    OUTPUT_VOLTAGE_ADC_IsEndConversion(OUTPUT_VOLTAGE_ADC_WAIT_FOR_RESULT);
+    uint16_t samples = OUTPUT_VOLTAGE_ADC_GetResult16();
+    return OUTPUT_VOLTAGE_ADC_CountsTo_mVolts(samples);
+}
+
+static void read_output_voltages(struct voltages* v)
+{
+    SIDE_REG_Write(1); /* set DIR to low (remember this is inverted) */
+    CyDelay(100);
+    v->logic0_mv = read_output_voltage_mv();
+
+    SIDE_REG_Write(0);
+    CyDelay(100);
+    v->logic1_mv = read_output_voltage_mv();
+}
+
+static uint16_t read_input_voltage_mv(void)
+{
+    INPUT_VOLTAGE_ADC_StartConvert();
+    INPUT_VOLTAGE_ADC_IsEndConversion(INPUT_VOLTAGE_ADC_WAIT_FOR_RESULT);
+    uint16_t samples = INPUT_VOLTAGE_ADC_GetResult16();
+    return INPUT_VOLTAGE_ADC_CountsTo_mVolts(samples);
+}
+
+static void read_input_voltages(struct voltages* v)
+{
+    home();
+    CyDelay(50);
+    v->logic0_mv = read_input_voltage_mv();
+
+    step(STEP_AWAYFROM0);
+    CyDelay(50);
+    v->logic1_mv = read_input_voltage_mv();
+}
+
+static void cmd_measure_voltages(void)
+{
+    stop_motor();
+    INPUT_VOLTAGE_ADC_Start();
+    INPUT_VOLTAGE_ADC_SetPower(INPUT_VOLTAGE_ADC__HIGHPOWER);
+    OUTPUT_VOLTAGE_ADC_Start();
+    OUTPUT_VOLTAGE_ADC_SetPower(OUTPUT_VOLTAGE_ADC__HIGHPOWER);
+
+    DECLARE_REPLY_FRAME(struct voltages_frame, F_FRAME_MEASURE_VOLTAGES_REPLY);
+
+    CyWdtClear();
+    MOTOR_REG_Write(0); /* should be ignored anyway */
+    DRIVESELECT_REG_Write(0); /* deselect both drives */
+    CyDelay(200); /* wait for things to settle */
+    read_output_voltages(&r.output_both_off);
+    read_input_voltages(&r.input_both_off);
+
+    CyWdtClear();
+    DRIVESELECT_REG_Write(1); /* select drive 0 */
+    CyDelay(50);
+    read_output_voltages(&r.output_drive_0_selected);
+    read_input_voltages(&r.input_drive_0_selected);
+    MOTOR_REG_Write(1);
+    CyDelay(300);
+    CyWdtClear();
+    read_output_voltages(&r.output_drive_0_running);
+    read_input_voltages(&r.input_drive_0_running);
+    MOTOR_REG_Write(0);
+    CyDelay(300);
+
+    CyWdtClear();
+    DRIVESELECT_REG_Write(2); /* select drive 1 */
+    CyDelay(50);
+    read_output_voltages(&r.output_drive_1_selected);
+    read_input_voltages(&r.input_drive_1_selected);
+    MOTOR_REG_Write(1);
+    CyDelay(300);
+    CyWdtClear();
+    read_output_voltages(&r.output_drive_1_running);
+    read_input_voltages(&r.input_drive_1_running);
+    MOTOR_REG_Write(0);
+    CyDelay(300);
+
+    CyWdtClear();
+    DRIVESELECT_REG_Write(0);
+    homed = false;
+    INPUT_VOLTAGE_ADC_Stop();
+    OUTPUT_VOLTAGE_ADC_Stop();
+    send_reply((struct any_frame*) &r);
+}
+
 static void handle_command(void)
 {
     static uint8_t input_buffer[FRAME_SIZE];
@@ -663,6 +773,10 @@ static void handle_command(void)
         case F_FRAME_SET_DRIVE_CMD:
             cmd_set_drive((struct set_drive_frame*) f);
             break;
+
+        case F_FRAME_MEASURE_VOLTAGES_CMD:
+            cmd_measure_voltages();
+            break;
 
         default:
             send_error(F_ERROR_BAD_COMMAND);
@@ -677,7 +791,9 @@ int main(void)
     INDEX_IRQ_StartEx(&index_irq_cb);
     CAPTURE_DMA_FINISHED_IRQ_StartEx(&capture_dma_finished_irq_cb);
     SEQUENCER_DMA_FINISHED_IRQ_StartEx(&replay_dma_finished_irq_cb);
-    DRIVE_REG_Write(0);
+    INPUT_VOLTAGE_ADC_Stop();
+    OUTPUT_VOLTAGE_ADC_Stop();
+    DRIVESELECT_REG_Write(0);
     UART_Start();
     USBFS_Start(0, USBFS_DWR_VDDD_OPERATION);
 
@@ -710,6 +826,7 @@ int main(void)
 
         if (USBFS_GetEPState(FLUXENGINE_CMD_OUT_EP_NUM) == USBFS_OUT_BUFFER_FULL)
         {
+            set_drive_flags(current_drive_flags);
             handle_command();
             USBFS_EnableOutEP(FLUXENGINE_CMD_OUT_EP_NUM);
             print("idle");

doc/using.md

@@ -51,7 +51,7 @@ In order to do anything useful, you have to plug it in to a floppy disk drive (o
      rpm for a 3.5" disk, or 360 rpm for a 5.25" disk. If it doesn't, please
      [get in touch](https://github.com/davidgiven/fluxengine/issues/new).
 
-  7. Do `fluxengine testbulktransport` from the shell. It'll measure your USB
+  7. Do `fluxengine test bulktransport` from the shell. It'll measure your USB
      bandwidth. Ideally you should be getting above 900kB/s. FluxEngine needs
      about 850kB/s, so if you're getting less than this, try a different USB
      port.
@@ -213,10 +213,13 @@ directory.
   - `fluxengine seek`: moves the head. Mainly useful for finding out whether
   your drive can seek to track 82. (Mine can't.)
 
-  - `fluxengine testbulktransport`: measures your USB throughput. You need
+  - `fluxengine test bulktransport`: measures your USB throughput. You need
   about 600kB/s for FluxEngine to work. You don't need a disk in the drive
   for this one.
 
+  - `fluxengine test voltages`: measures your FDD bus signal voltages, which
+  is useful for testing for termination issues.
+
   - `fluxengine upgradefluxfile`: occasionally I need to upgrade the flux
   file format in a non-backwards-compatible way; this tool will upgrade flux
   files to the new format.

lib/usb.cc

@@ -265,3 +265,37 @@ void usbSetDrive(int drive, bool high_density)
     await_reply<struct any_frame>(F_FRAME_SET_DRIVE_REPLY);
 }
 
+/* Hacky: the board always operates in little-endian mode. */
+static uint16_t read_short_from_usb(uint16_t usb)
+{
+    uint8_t* p = (uint8_t*)&usb;
+    return p[0] | (p[1] << 8);
+}
+
+static void convert_voltages_from_usb(const struct voltages& vin, struct voltages& vout)
+{
+    vout.logic0_mv = read_short_from_usb(vin.logic0_mv);
+    vout.logic1_mv = read_short_from_usb(vin.logic1_mv);
+}
+
+void usbMeasureVoltages(struct voltages_frame* voltages)
+{
+    usb_init();
+
+    struct any_frame f = {
+        { .type = F_FRAME_MEASURE_VOLTAGES_CMD, .size = sizeof(f) },
+    };
+    usb_cmd_send(&f, f.f.size);
+
+    struct voltages_frame* r = await_reply<struct voltages_frame>(F_FRAME_MEASURE_VOLTAGES_REPLY);
+    convert_voltages_from_usb(r->input_both_off, voltages->input_both_off);
+    convert_voltages_from_usb(r->input_drive_0_selected, voltages->input_drive_0_selected);
+    convert_voltages_from_usb(r->input_drive_1_selected, voltages->input_drive_1_selected);
+    convert_voltages_from_usb(r->input_drive_0_running, voltages->input_drive_0_running);
+    convert_voltages_from_usb(r->input_drive_1_running, voltages->input_drive_1_running);
+    convert_voltages_from_usb(r->output_both_off, voltages->output_both_off);
+    convert_voltages_from_usb(r->output_drive_0_selected, voltages->output_drive_0_selected);
+    convert_voltages_from_usb(r->output_drive_1_selected, voltages->output_drive_1_selected);
+    convert_voltages_from_usb(r->output_drive_0_running, voltages->output_drive_0_running);
+    convert_voltages_from_usb(r->output_drive_1_running, voltages->output_drive_1_running);
+}

lib/usb.h

@@ -13,5 +13,6 @@ extern Bytes usbRead(int side, int revolutions);
 extern void usbWrite(int side, const Bytes& bytes);
 extern void usbErase(int side);
 extern void usbSetDrive(int drive, bool high_density);
+extern void usbMeasureVoltages(struct voltages_frame* voltages);
 
 #endif

mkninja.sh

@@ -212,6 +212,7 @@ buildlibrary libfrontend.a \
     src/fe-scptoflux.cc \
     src/fe-seek.cc \
     src/fe-testbulktransport.cc \
+    src/fe-testvoltages.cc \
     src/fe-upgradefluxfile.cc \
     src/fe-writebrother.cc \
     src/fe-writeflux.cc \

protocol.h

@@ -62,6 +62,8 @@ enum
     F_FRAME_RECALIBRATE_REPLY,    /* any_frame */
     F_FRAME_SET_DRIVE_CMD,        /* setdrive_frame */
     F_FRAME_SET_DRIVE_REPLY,      /* any_frame */
+    F_FRAME_MEASURE_VOLTAGES_CMD, /* any_frame */
+    F_FRAME_MEASURE_VOLTAGES_REPLY, /* voltages_frame */
 };
 
 enum
@@ -146,4 +148,25 @@ struct set_drive_frame
     uint8_t drive_flags;
 };
 
+struct voltages
+{
+    uint16_t logic0_mv;
+    uint16_t logic1_mv;
+};
+
+struct voltages_frame
+{
+    struct frame_header f;
+    struct voltages output_both_off;
+    struct voltages output_drive_0_selected;
+    struct voltages output_drive_1_selected;
+    struct voltages output_drive_0_running;
+    struct voltages output_drive_1_running;
+    struct voltages input_both_off;
+    struct voltages input_drive_0_selected;
+    struct voltages input_drive_1_selected;
+    struct voltages input_drive_0_running;
+    struct voltages input_drive_1_running;
+};
+
 #endif

src/fe-readmx.cc

@@ -8,7 +8,6 @@
 #include "sector.h"
 #include "sectorset.h"
 #include "record.h"
-#include <fmt/format.h>
 
 static FlagGroup flags { &readerFlags };
 

src/fe-testvoltages.cc

@@ -0,0 +1,47 @@
+#include "globals.h"
+#include "flags.h"
+#include "usb.h"
+#include "protocol.h"
+#include <fmt/format.h>
+
+static FlagGroup flags;
+
+static std::string display_voltages(struct voltages& v)
+{
+    return fmt::format(
+        "      Logic 1 / 0:  {:.2f}V / {:.2f}V\n",
+        v.logic0_mv / 1000.0,
+        v.logic1_mv / 1000.0);
+}
+
+int mainTestVoltages(int argc, const char* argv[])
+{
+    flags.parseFlags(argc, argv);
+    struct voltages_frame f;
+    usbMeasureVoltages(&f);
+
+    std::cout << "Output voltages:\n"
+              << "  Both drives deselected\n"
+              << display_voltages(f.output_both_off)
+              << "  Drive 0 selected\n"
+              << display_voltages(f.output_drive_0_selected)
+              << "  Drive 1 selected\n"
+              << display_voltages(f.output_drive_1_selected)
+              << "  Drive 0 running\n"
+              << display_voltages(f.output_drive_0_running)
+              << "  Drive 1 running\n"
+              << display_voltages(f.output_drive_1_running)
+              << "Input voltages:\n"
+              << "  Both drives deselected\n"
+              << display_voltages(f.input_both_off)
+              << "  Drive 0 selected\n"
+              << display_voltages(f.input_drive_0_selected)
+              << "  Drive 1 selected\n"
+              << display_voltages(f.input_drive_1_selected)
+              << "  Drive 0 running\n"
+              << display_voltages(f.input_drive_0_running)
+              << "  Drive 1 running\n"
+              << display_voltages(f.input_drive_1_running);
+
+    return 0;
+}