GUI reads ADC channel

.gitignore

@@ -3,4 +3,5 @@ ChibiOS_*
 **/.*
 gui/stmdspgui
 *.o
+perf*
 

gui/stmdsp.cpp

@@ -14,4 +14,24 @@ namespace stmdsp
 
         return m_available_devices;
     }
+
+    device::device(const std::string& file) :
+        m_serial(file, 230400, serial::Timeout::simpleTimeout(50)) {}
+
+    std::vector<adcsample_t> device::sample(unsigned long int count) {
+        if (connected()) {
+            uint8_t request[3] = {
+                'r',
+                static_cast<uint8_t>(count),
+                static_cast<uint8_t>(count >> 8)
+            };
+            m_serial.write(request, 3);
+            std::vector<adcsample_t> data (count);
+            m_serial.read(reinterpret_cast<uint8_t *>(data.data()),
+                          data.size() * sizeof(adcsample_t));
+            return data;
+        } else {
+            return {};
+        }
+    }
 }

gui/stmdsp.hpp

@@ -28,8 +28,7 @@ namespace stmdsp
     class device
     {
     public:
-        device(const std::string& file) :
-            m_serial(file, 115200, serial::Timeout::simpleTimeout(1000)) {}
+        device(const std::string& file);
 
         ~device() {
             m_serial.close();
@@ -39,19 +38,7 @@ namespace stmdsp
             return m_serial.isOpen() && (m_serial.write("i"), m_serial.read(6) == "stmdsp");
         }
 
-        std::vector<adcsample_t> sample(unsigned long int count = 1) {
-            if (connected()) {
-                m_serial.write(std::vector<uint8_t> {'r',
-                                                     static_cast<uint8_t>(count),
-                                                     static_cast<uint8_t>(count >> 8)});
-                std::vector<adcsample_t> data (count);
-                m_serial.read(reinterpret_cast<uint8_t *>(data.data()),
-                              data.size() * sizeof(adcsample_t));
-                return data;
-            } else {
-                return {};
-            }
-        }
+        std::vector<adcsample_t> sample(unsigned long int count = 1);
 
     private:
         serial::Serial m_serial;

gui/wxmain.hpp

@@ -3,6 +3,8 @@
 
 #include "stmdsp.hpp"
 
+#include <future>
+#include <thread>
 #include <wx/button.h>
 #include <wx/combobox.h>
 #include <wx/dcclient.h>
@@ -21,22 +23,26 @@ class MainFrame : public wxFrame
 
     bool m_is_rendering = false;
     wxTimer *m_render_timer = nullptr;
-    int m_radius = 10;
+    wxComboBox *m_device_combo = nullptr;
 
     const wxRect m_clipping_region = {20, 100, 600, 360};
 
+    stmdsp::device *m_device = nullptr;
+    std::future<std::vector<stmdsp::adcsample_t>> m_device_samples_future;
+    std::vector<stmdsp::adcsample_t> m_device_samples;
+
 public:
     MainFrame() : wxFrame(nullptr, -1, "Hello world", wxPoint(50, 50), wxSize(640, 480))
     {
         new wxStaticText(this, Id::Welcome, "Welcome to the GUI.", wxPoint(20, 20));
         new wxButton(this, Id::Single, "Single", wxPoint(20, 60));
-        auto combo = new wxComboBox(this, Id::SelectDevice, "", wxPoint(470, 20), wxSize(150, 30));
-        combo->SetEditable(false);
+        m_device_combo = new wxComboBox(this, Id::SelectDevice, "", wxPoint(470, 20), wxSize(150, 30));
+        m_device_combo->SetEditable(false);
         stmdsp::scanner scanner;
         for (auto& dev : scanner.scan())
-            combo->Append(dev);
-        if (combo->GetCount() > 0)
-            combo->SetSelection(0);
+            m_device_combo->Append(dev);
+        if (m_device_combo->GetCount() > 0)
+            m_device_combo->SetSelection(0);
 
         m_render_timer = new wxTimer(this, Id::RenderTimer);
 
@@ -53,19 +59,47 @@ public:
         dc->SetPen(*wxBLACK_PEN);
         dc->DrawRectangle(m_clipping_region);
 
+        if (m_device_samples.size() > 0) {
             dc->SetPen(*wxRED_PEN);
-        dc->DrawCircle(320, 240, m_radius);
+            auto points = new wxPoint[m_device_samples.size()];
+            const float spacing = static_cast<float>(m_clipping_region.GetWidth()) / m_device_samples.size();
+            float x = 0;
+            for (auto ptr = points; auto sample : m_device_samples) {
+                *ptr++ = wxPoint {
+                    static_cast<int>(x),
+                    m_clipping_region.GetHeight() - sample * m_clipping_region.GetHeight() / 4096
+                };
+                x += spacing;
+            }
+            dc->DrawLines(m_device_samples.size(), points, m_clipping_region.GetX(), m_clipping_region.GetY());
+            delete[] points;
+        }
+    }
+
+    void doSingle() {
+        m_device_samples_future = std::async(std::launch::async,
+                                             [this]() { return m_device->sample(250); });
     }
 
     void onSinglePressed(wxCommandEvent& ce) {
         auto button = dynamic_cast<wxButton *>(ce.GetEventObject());
 
         if (!m_render_timer->IsRunning()) {
+            m_device = new stmdsp::device(m_device_combo->GetStringSelection().ToStdString());
+            if (m_device->connected()) {
+                doSingle();
                 m_render_timer->Start(100);
                 button->SetLabel("Stop");
+            } else {
+                delete m_device;
+                m_device = nullptr;
+            }
         } else {
             m_render_timer->Stop();
             button->SetLabel("Single");
+
+            delete m_device;
+            m_device = nullptr;
         }
     }
 
@@ -74,8 +108,10 @@ public:
     }
 
     void updateDrawing() {
-        m_radius++;
+        if (m_device_samples = m_device_samples_future.get(); m_device_samples.size() > 0)
             this->RefreshRect(m_clipping_region);
+
+        doSingle();
     }
 };
 

source/main.cpp

@@ -23,7 +23,7 @@ static_assert(sizeof(adcsample_t) == sizeof(uint16_t));
 #if CACHE_LINE_SIZE > 0
 CC_ALIGN(CACHE_LINE_SIZE)
 #endif
-static std::array<adcsample_t, CACHE_SIZE_ALIGN(adcsample_t, 100)> adc_samples;
+static std::array<adcsample_t, CACHE_SIZE_ALIGN(adcsample_t, 2048)> adc_samples;
 
 int main()
 {
@@ -49,11 +49,13 @@ int main()
 	while (true) {
         if (usbd.active()) {
             // Expect to receive a byte command 'packet'.
-            if (char cmd; usbd.read(&cmd) > 0) {
-                switch (cmd) {
+            if (char cmd[3]; usbd.read(&cmd, 3) > 0) {
+                switch (cmd[0]) {
                 case 'r': // Read in analog signal
-                    adc.getSamples(&adc_samples[0], 100);//adc_samples.size());
-                    usbd.write(adc_samples.data(), adc_samples.size());
+                    if (auto count = std::min(static_cast<unsigned int>(cmd[1] | (cmd[2] << 8)), adc_samples.size()); count > 0) {
+                        adc.getSamples(&adc_samples[0], count);
+                        usbd.write(adc_samples.data(), count * sizeof(adcsample_t));
+                    }
                     break;
                 case 'i': // Identify ourself as an stmdsp device
                     usbd.write("stmdsp", 6);
@@ -64,7 +66,7 @@ int main()
             }
         }
 
-		chThdSleepMilliseconds(250);
+		chThdSleepMilliseconds(1);
 	}
 }