Dev/decode my302 (#254)

This PR adds support for decoding digital data from the my320 test chip.
- Added BitOffset (strong type)
- Expand 24 to 32 bit 
- Python bindings for decoding my302
- Improved docs

python/src/ctb_raw_file.hpp

@@ -96,6 +96,69 @@ void define_ctb_raw_file_io_bindings(py::module &m) {
               return output;
           });
 
+    m.def("expand24to32bit",
+    [](py::array_t<uint8_t, py::array::c_style | py::array::forcecast>
+                 &input, uint32_t offset){
+
+            aare::BitOffset bitoff(offset);
+            py::buffer_info buf = input.request();
+
+            constexpr uint32_t bytes_per_channel = 3; //24 bit
+            py::array_t<uint32_t> output(buf.size/bytes_per_channel);
+
+            NDView<uint8_t, 1> input_view(input.mutable_data(),
+                                             {input.size()});
+            NDView<uint32_t, 1> output_view(output.mutable_data(),
+                                        {output.size()});
+
+            aare::expand24to32bit(input_view, output_view, bitoff);
+            return output;
+
+    });
+
+    m.def("decode_my302",
+    [](py::array_t<uint8_t, py::array::c_style | py::array::forcecast>
+                 &input, uint32_t offset){
+
+            // Physical layout of the chip
+            constexpr size_t channels = 64;
+            constexpr size_t counters = 3;
+            constexpr size_t bytes_per_channel = 3; //24 bit
+            constexpr int n_outputs = 2;
+
+            ssize_t expected_size = channels*counters*bytes_per_channel;
+
+            //If whe have an offset we need one extra byte per output
+            aare::BitOffset bitoff(offset);
+            if(bitoff.value())
+                expected_size += n_outputs;
+
+            if (input.size() != expected_size) {
+                throw std::runtime_error(
+                    fmt::format("{} Expected an input size of {} bytes. Called "
+                                "with input size of {}",
+                                LOCATION, expected_size, input.size()));
+            }
+
+            py::buffer_info buf = input.request();
+            py::array_t<uint32_t> output(channels * counters);
+
+            for (int i = 0; i!=n_outputs; ++i){
+                auto step = input.size()/n_outputs;
+                auto out_step = output.size()/n_outputs;
+                NDView<uint8_t, 1> input_view(input.mutable_data()+step*i,
+                                             {input.size()/n_outputs});
+                NDView<uint32_t, 1> output_view(output.mutable_data()+out_step*i,
+                                            {output.size()/n_outputs});
+
+                aare::expand24to32bit(input_view, output_view, bitoff);
+
+            }
+            
+            return output;
+
+    });
+
     py::class_<CtbRawFile>(m, "CtbRawFile")
         .def(py::init<const std::filesystem::path &>())
         .def("read_frame",