Merge pull request #11 from LennertW/main

external_hvp mode and another injection tip example

firmware/c/README.md

@@ -7,6 +7,7 @@ It currently supports:
 - Serial interface for arming/disarming/pulsing
 - Automatic disarm after 60 seconds
 - Fast-trigger via GPIO0 (uses PIO for very fast and consistent triggering)
+- External HVP mode: use an external pulse generator (e.g. ChipWhisperer) to control EM pulse insertion
 
 ## Building
 
@@ -16,4 +17,4 @@ mkdir build
 cd build
 cmake ..
 make
-```
+```

firmware/c/main.c

@@ -11,7 +11,9 @@
 
 static bool armed = false;
 static bool timeout_active = true;
+static bool hvp_internal = true;
 static absolute_time_t timeout_time;
+static uint offset = 0xFFFFFFFF;
 
 void arm() {
     gpio_put(PIN_LED_CHARGE_ON, true);
@@ -35,6 +37,9 @@ uint32_t get_status() {
     if(timeout_active) {
         result |= 0b100;
     }
+    if(hvp_internal) {
+        result |= 0b1000;
+    }
     return result;
 }
 
@@ -50,8 +55,10 @@ void fast_trigger() {
     // memory. This SDK function will find a location (offset) in the
     // instruction memory where there is enough space for our program. We need
     // to remember this location!
-    uint offset = pio_add_program(pio, &trigger_program);
-
+    if (offset == 0xFFFFFFFF) { // Only load the program once
+        offset = pio_add_program(pio, &trigger_program);
+    }
+
     // Find a free state machine on our chosen PIO (erroring if there are
     // none). Configure it to run our program, and start it, using the
     // helper function we included in our .pio file.
@@ -111,7 +118,16 @@ int main() {
                     pio_sm_set_enabled(pio0, 0, false);
                     picoemp_configure_pulse_output();
                     break;
-
+                case cmd_internal_hvp:
+                    picoemp_configure_pulse_output();
+                    hvp_internal = true;
+                    multicore_fifo_push_blocking(return_ok);
+                    break;
+                case cmd_external_hvp:
+                    picoemp_configure_pulse_external();
+                    hvp_internal = false;
+                    multicore_fifo_push_blocking(return_ok);
+                    break;
             }
         }
 

firmware/c/picoemp.c

@@ -83,6 +83,14 @@ void picoemp_configure_pulse_output() {
     gpio_put(PIN_OUT_HVPULSE, false);
 }
 
+void picoemp_configure_pulse_external() {
+    // Configure pulse input
+    gpio_init(PIN_OUT_HVPULSE);
+    gpio_set_dir(PIN_OUT_HVPULSE, GPIO_IN);
+    // No pullups & pulldowns
+    gpio_set_pulls(PIN_OUT_HVPULSE, false, false);
+}
+
 void picoemp_init() {
     // Initialize LED GPIOs
     gpio_init(PIN_LED_HV);

firmware/c/picoemp.h

@@ -17,4 +17,5 @@ void picoemp_enable_pwm();
 void picoemp_disable_pwm();
 void picoemp_pulse();
 void picoemp_configure_pulse_output();
+void picoemp_configure_pulse_external();
 void picoemp_init();

firmware/c/serial.c

@@ -39,6 +39,7 @@ void print_status(uint32_t status) {
     bool armed = (status >> 0) & 1;
     bool charged = (status >> 1) & 1;
     bool timeout_active = (status >> 2) & 1;
+    bool hvp_mode = (status >> 3) & 1;
     printf("Status:\n");
     if(armed) {
         printf("- Armed\n");
@@ -55,6 +56,11 @@ void print_status(uint32_t status) {
     } else {
         printf("- Timeout disabled\n");
     }
+    if(hvp_mode) {
+        printf("- HVP internal\n");
+    } else {
+        printf("- HVP external\n");
+    }
 }
 
 bool handle_command(char *command) {
@@ -130,6 +136,26 @@ bool handle_command(char *command) {
         }
         return true;
     }
+    if(strcmp(command, "internal_hvp") == 0) {
+        multicore_fifo_push_blocking(cmd_internal_hvp);
+        uint32_t result = multicore_fifo_pop_blocking();
+        if(result == return_ok) {
+            printf("Internal HVP mode active!\n");
+        } else {
+            printf("Setting up internal HVP mode failed.");
+        }
+        return true;
+    }
+    if(strcmp(command, "external_hvp") == 0) {
+        multicore_fifo_push_blocking(cmd_external_hvp);
+        uint32_t result = multicore_fifo_pop_blocking();
+        if(result == return_ok) {
+            printf("External HVP mode active!\n");
+        } else {
+            printf("Setting up external HVP mode failed.");
+        }
+        return true;
+    }
 
     if(strcmp(command, "reset") == 0) {
         watchdog_enable(1, 1);
@@ -151,6 +177,8 @@ void serial_console() {
             printf("- enable_timeout\n");
             printf("- disable_timeout\n");
             printf("- fast_trigger\n");
+            printf("- internal_hvp\n");
+            printf("- external_hvp\n");
             printf("- status\n");
             printf("- reset\n");
         }

firmware/c/serial.h

@@ -8,6 +8,8 @@
 #define cmd_enable_timeout 4
 #define cmd_disable_timeout 5
 #define cmd_fast_trigger 6
+#define cmd_internal_hvp 7
+#define cmd_external_hvp 8
 #define return_ok 0
 #define return_failed 1
 

hardware/injection_tips/README.md

@@ -63,6 +63,13 @@ The following is a smaller inductor, Wurth `744710603` (available on Digi-Key):
 You need to unwind a wrapping to connect to the SMA. I'd consider trying this coil with less windings
 as well (unwrap more windings, but keep the windings as close to the 'active' end as possible).
 
+
+Alternatively you can also try experimenting with [radial leaded wire wound inductors](https://www.we-online.com/catalog/en/WE-TI#/articles/WE-TI-6065).
+Pictured is a modified `744779068` inductor that has the top ferrite cover and a few windings removed.
+
+![](examples/tip_WE_744779068.jpg)
+
+
 ### Shapping Ferrite Core
 
 The following shows the Wurth `744710603` shaped, along with a small ferrite toroid (`35T0119-00P`):