README.md

@@ -1,68 +1,30 @@
-# CMOCKA/CMAKE template
+# gy-521 Driver
 
-## Purporse
+The gy-521 module is usally interfaced with via TWI/I2C. The actual chip that
+is used in the module is the mpu6050 ic.
 
-- Streamline the setup of new C projects
-- Make it easy to setup a develoment enviroment
-- Allow TDD for embedded systems
-- Provide easy LSP usage via compile_commands.json
-- correctly use the CTEST command.
-- Avoid having to setup ruby/ceedling with it's dependency hell
+This driver doesn't make any assumptions about the platform it will run
+on beyond that it supports "stdlib.h" and "inttypes.h".
 
-## Organization
+The interface handles all the register and bitshift operations in the 
+the backgorund. The module uses getters and setters to abstract the
+actual data. This prevents the end user from trying to directly use the 
+structures data when it is volatile and may be setup to update in a ISR.
 
-```
-.
-├── CMakeLists.txt
-├── LICENSE
-├── README.md
-├── build
-├── cmake
-│   └── cmocka
-│       ├── AddCCompilerFlag.cmake
-│       ├── AddCMockaTest.cmake
-│       ├── COPYING-CMAKE-SCRIPTS
-│       ├── CheckCCompilerFlagSSP.cmake
-│       ├── DefineCMakeDefaults.cmake
-│       ├── DefineCompilerFlags.cmake
-│       ├── DefinePlatformDefaults.cmake
-│       ├── FindNSIS.cmake
-│       └── MacroEnsureOutOfSourceBuild.cmake
-├── compile_commands.json -> ./build/compile_commands.json
-├── git_modules
-├── src
-│   ├── CMakeLists.txt
-│   ├── led_driver
-│   │   ├── CMakeLists.txt
-│   │   ├── led_driver.c
-│   │   └── led_driver.h
-│   ├── main.c
-│   └── main.h
-└── tests
-    ├── CMakeLists.txt
-    ├── led_driver
-    │   ├── CMakeLists.txt
-    │   └── test_led_driver.c
-    └── simple_test
-        ├── CMakeLists.txt
-        └── simple_test.c
+## PINs
 
-10 directories, 24 files
-```
-
-The actual code is all stored inside the src direcotry with any libs/submodules
-stored inside their own subdirectories.
-
-The code we use to test stuff gets stored inside the dir "tests" in the 
-projects root.
-
-The compile_commands.json file in the project root is actaully a symlink to
-the generated compile_commands.json file inside the build directory. So if
-you notice your LSP isn't working correctly it probably means that you haven't
-ran cmake yet.
+- VCC: 3.3v
+- GND: ground or 0v
+- SCL: TWI clock
+- SDA: TWI data
+- XDA:
+- XCL:
+- AD0: changes the TWI address when pulled high.
+- INT: interrupt pin
 
 
 ## Running and building the project
+The project uses CMake along with cmocka for unit testing.
 
 ```sh
 # change into the build dir
@@ -76,33 +38,12 @@ ctest
 
 ```
 
-# Adding tests
-
-To actually add tests to the project create a new directory inside the
-"tests" dir. From there it will need a source.c and CMAKELists.txt file.
-
-You will also need to include it inside the tests/CMakeLists.txt file as well.
-
-```cmake
-add_subdirectory(new_test)
-```
-
 ## RoadMap
 
-Things I want to add in the future:
-
-- Automatic module creation
-- template generation
-- header --> mocking
-- report generation
-- embedded specific scripts for common hardware items
-
-
-
-
-##TDD stuff
-
-- what does a struct typedef <name_struct> \*struct actually mean?
+- add in functions for interrupt driven updates.
+- add functions for configuration of module.
+- add functions to save configurations in memory.
+- add functions to load saved configs
 
 
 

src/gy521_driver/gy521_driver.c

@@ -1,7 +1,7 @@
 /*
  * Author: Jake Goodwin
  * Date: 2023
- * Description:
+ * Description: The implimentation file for the gy521 module, assumes TWI/I2c
  */
 #include "gy521_driver.h"
 #include <stdint.h>
@@ -18,6 +18,9 @@ extern void _test_free(void* const ptr, const char* file, const int line);
 #define free(ptr) _test_free(ptr, __FILE__, __LINE__)
 #endif // UNIT_TESTING
 
+#define     NUM_ACCEL_REGS  6
+#define     NUM_GYRO_REGS   6
+
 /*
  * ############################
  * REGISTER MAP 
@@ -25,6 +28,20 @@ extern void _test_free(void* const ptr, const char* file, const int line);
  */ 
 
 enum gy521_map {
+    accel_xouth = 0x3B,
+    accel_xoutl,
+    accel_youth,
+    accel_youtl,
+    accel_zouth,
+    accel_zoutl,
+    temp_outh,
+    temp_outl,
+    gyro_xouth,
+    gyro_xoutl,
+    gyro_youth,
+    gyro_youtl,
+    gyro_zouth,
+    gyro_zoutl,
     fifo_couth = 0x72,
     fifo_contl,
     fifo_r_w,
@@ -37,17 +54,7 @@ enum gy521_map {
  * ############################
  */ 
 
-typedef struct{
-    uint16_t x;
-    uint16_t y;
-    uint16_t z;
-}gyro_values_struct;
 
-typedef struct{
-    uint16_t x;
-    uint16_t y;
-    uint16_t z;
-}accel_values_struct;
 
 struct gy521_module{
     uint8_t slave_address;
@@ -55,6 +62,30 @@ struct gy521_module{
     accel_values_struct accel;
 };
 
+/*
+ * ############################
+ * Helper/Private Functions
+ * ############################
+ */ 
+    
+uint8_t read_register(gy521_module *m, enum gy521_map reg)
+{
+    /*Load the data var with athe address of the register to read*/
+    uint8_t data = reg;
+
+    /*Indicate we want to read a value from the slave.*/
+    gy521_twi_rx(m->slave_address, &data, 1);
+
+    /*The value should now be in the data var*/
+    return data;
+}
+
+void write_register(gy521_module *m, enum gy521_map reg, uint8_t data)
+{
+    gy521_twi_tx(m->slave_address, (uint8_t *) &reg, data);
+}
+
+
 /*
  * ############################
  * Function Definitions
@@ -63,7 +94,6 @@ struct gy521_module{
 
 gy521_module* gy521_new(void)
 {
-    //gy521_module *m = malloc(sizeof(gy521_module));
     gy521_module *m = (gy521_module *)malloc(sizeof(gy521_module));
     m->slave_address = 0x0;
     return m;
@@ -75,7 +105,9 @@ void gy521_free(gy521_module *m)
     free(m);
 }
 
+
 _Bool gy521_init(gy521_module *m, uint8_t slave_address) {
+    /*Check to make sure it's a valid address for this module*/
     if((slave_address != TWI_GY521_ADDR1) && (slave_address != TWI_GY521_ADDR2)) { 
         m->slave_address = 0x0;
         return 0;
@@ -84,10 +116,8 @@ _Bool gy521_init(gy521_module *m, uint8_t slave_address) {
     /*Set the slave address of the module*/
     m->slave_address = slave_address;
 
-    /*Try  to talk with i2c module.*/
-    uint8_t data = who_am_i;
-    gy521_twi_tx(m->slave_address, &data, 1);
-    gy521_twi_rx(m->slave_address, &data, 1);
+    /*Make sure TWI is working and read the who_am_i register*/
+    uint8_t data = read_register(m, who_am_i);
     
     if(data != m->slave_address) {
         return 0;
@@ -97,12 +127,44 @@ _Bool gy521_init(gy521_module *m, uint8_t slave_address) {
 }
 
 
-_Bool gy521_update_gyro(gy521_module *m)
+void gy521_update_accel(gy521_module *m)
 {
-    return 0;
+    /*We shift the High byte over by 8 for a u16*/
+    m->accel.x = read_register(m, accel_xouth) <<8;
+    m->accel.x |= read_register(m, accel_xoutl);
+    m->accel.y = read_register(m, accel_youth) <<8;
+    m->accel.y |= read_register(m, accel_youtl);
+    m->accel.z = read_register(m, accel_zouth) <<8;
+    m->accel.z |= read_register(m, accel_zoutl);
 }
 
-_Bool gy521_update_accel(gy521_module *m)
+void gy521_update_gyro(gy521_module *m)
 {
-    return 0;
+    /*We shift the High byte over by 8 for a u16*/
+    m->gyro.x = read_register(m, gyro_xouth) <<8;
+    m->gyro.x |= read_register(m, gyro_xoutl);
+    m->gyro.y = read_register(m, gyro_youth) <<8;
+    m->gyro.y |= read_register(m, gyro_youtl);
+    m->gyro.z = read_register(m, gyro_zouth) <<8;
+    m->gyro.z |= read_register(m, gyro_zoutl);
+}
+
+
+struct accel_values gy521_get_accel(struct gy521_module* m)
+{
+    struct accel_values s;
+    s.x = m->accel.x;
+    s.y = m->accel.y;
+    s.z = m->accel.z;
+    return s;
+}
+
+
+struct gyro_values gy521_get_gyro(struct gy521_module* m)
+{
+    struct gyro_values s;
+    s.x = m->gyro.x;
+    s.y = m->gyro.y;
+    s.z = m->gyro.z;
+    return s;
 }

src/gy521_driver/gy521_driver.h

@@ -1,7 +1,7 @@
 /*
  * Author: Jake Goodwin
  * Date: 2023
- * Description:
+ * Description: A Generic driver for gy521 IMU modules
  */
 
 #ifndef GY521_DRIVER_H
@@ -25,6 +25,18 @@
  * Types/Structures 
  * ############################
  */
+typedef struct gyro_values{
+    uint16_t x;
+    uint16_t y;
+    uint16_t z;
+}gyro_values_struct;
+
+typedef struct accel_values{
+    uint16_t x;
+    uint16_t y;
+    uint16_t z;
+}accel_values_struct;
+
 typedef struct gy521_module gy521_module;
 
 /*
@@ -42,9 +54,13 @@ extern void (*gy521_twi_rx)(uint8_t, uint8_t*, uint8_t);
 
 struct gy521_module* gy521_new(void);
 _Bool gy521_init(struct gy521_module *m, uint8_t slave_address);
-_Bool gy521_update_gyro(struct gy521_module* m);
-_Bool gy521_update_accel(struct gy521_module* m);
+void gy521_update_gyro(struct gy521_module* m);
+void gy521_update_accel(struct gy521_module* m);
 void gy521_free(struct gy521_module *m);
 
+/*These are used instead of direct access; assuming interrupt driven*/
+/*updates to the gy521 then it protects the user from using volatile values*/
+struct accel_values gy521_get_accel(struct gy521_module* m);
+struct gyro_values gy521_get_gyro(struct gy521_module* m);
 
 #endif /* GY521_DRIVER_H */   

tests/gy521_driver/test_gy521_driver.c

@@ -8,23 +8,46 @@
 
 #define WRITE_BIT   (1<<7)
 
-uint8_t fake_twi_addr = 0x0;
-uint8_t fake_twi_data[16] = {0x0};
+typedef struct reg_addr{
+    uint8_t dev_addr;
+    uint8_t addr;
+    uint8_t value;
+}reg_addr;
 
+reg_addr reg_addr_arr[16] = {{0x0, 0x0, 0x0}};
+uint8_t idx = 0;
 
 /* Fake Object for TWI_TX*/
 void fake_twi_tx(uint8_t slave_addr, uint8_t *data, uint8_t size)
 {
-    fake_twi_addr = slave_addr; 
+    /*Save the slave address passed*/
+    reg_addr_arr[0].dev_addr = slave_addr;
+
+    /*Now write all the passed data*/
+    for(; idx < size; idx++) {
+        reg_addr_arr[idx].addr = *(data);
+        reg_addr_arr[idx].value = *(++data);
+    } 
+    /*Post increment the global index*/
+    idx++;
 }
 
 /* Fake Object for TWI_RX*/
 void fake_twi_rx(uint8_t slave_addr, uint8_t *data, uint8_t size)
 {
-    fake_twi_addr = slave_addr;
-    for(int i = 0; i < size; i++) {
-        *data++ = fake_twi_data[i];
+    /*Save the slave address passed*/
+    reg_addr_arr[0].dev_addr = slave_addr;
+    
+    /*Read the registers requested*/
+    for(uint8_t i = 0; i < size; i++) {
+        /*Wridxte the register read address*/
+        reg_addr_arr[i + idx].addr = *(data + i);
+        
+        /*Read the response value into the pased data ptr*/
+        *(data + i) = reg_addr_arr[i + idx].value;
     }
+    /*Post increment the global index*/
+    idx++;
 }
 
 
@@ -43,33 +66,115 @@ static void test_gy521_init(void **state) {
     /*Check for it's confirmation of the right twi device*/
     assert_false(gy521_init(m, TWI_GY521_ADDR1));
 
-    /*Now give it the correct response*/
-    fake_twi_data[0] = TWI_GY521_ADDR1;
+    /*Fill the address and the value registers with correct response value*/
+    /*The zero element get's read on init of the module*/
+    reg_addr_arr[0].addr = TWI_GY521_ADDR1;
+    reg_addr_arr[0].value = TWI_GY521_ADDR1;
+    idx = 0;
+
+    /*Check that it worked*/
     assert_true(gy521_init(m, TWI_GY521_ADDR1));
-    assert_true(TWI_GY521_ADDR1 == fake_twi_addr); 
+    assert_true(TWI_GY521_ADDR1 == reg_addr_arr[0].dev_addr); 
 
 
-    fake_twi_data[0] = TWI_GY521_ADDR2;
+    reg_addr_arr[0].addr = TWI_GY521_ADDR2;
+    reg_addr_arr[0].value = TWI_GY521_ADDR2;
+    idx = 0;
+
     assert_true(gy521_init(m, TWI_GY521_ADDR2));
-    assert_true(TWI_GY521_ADDR2 == fake_twi_addr); 
+    assert_true(TWI_GY521_ADDR2 == reg_addr_arr[0].dev_addr); 
 
     gy521_free(m);
  
 }
 
 
-static void test_gy521_update(void **sate)
+static void test_gy521_update_accel(void **sate)
 {
-    assert_false(1);
+    /*check it reads the accel registers*/
+    gy521_module *m = gy521_new();
+    reg_addr_arr[0].addr = TWI_GY521_ADDR1;
+    gy521_init(m, TWI_GY521_ADDR1);
+    
+    /*Setup the fake accel values.*/
+    for(uint8_t i = 0; i < 6; i++) {
+        reg_addr_arr[i].value = i * 8;
     }
   
+    /*Zero the global index for the TWI*/ 
+    idx = 0;  
+    gy521_update_accel(m); 
+
+    /*Ensure the correct registers are read*/
+    _Bool is_correct = 1;
+    assert_true(is_correct);
+    for(uint8_t i = 0; i < 6; i++){
+        /*The starting address of the registers is 59 and goes to 64*/ 
+        if((59 + i) != reg_addr_arr[i].addr) {
+            is_correct = 0;
+        }
+    }
+    assert_true(is_correct);     
+
+    /*Check that the values are assembled correctly*/
+    struct accel_values accel = gy521_get_accel(m);
+
+    /*Make sure to bitshift by 8 and recomine the two u8 into a single u16*/
+    assert_true(accel.x == ((reg_addr_arr[0].value<<8) | reg_addr_arr[1].value));
+    assert_true(accel.y == ((reg_addr_arr[2].value<<8) | reg_addr_arr[3].value));
+    assert_true(accel.z == ((reg_addr_arr[4].value<<8) | reg_addr_arr[5].value));
+
+    gy521_free(m);
+}
+
+
+static void test_gy521_update_gyro(void **sate)
+{
+    /*check it reads the gyro registers*/
+    gy521_module *m = gy521_new();
+    reg_addr_arr[0].addr = TWI_GY521_ADDR1;
+    gy521_init(m, TWI_GY521_ADDR1);
+    
+    /*Setup the fake gyro values.*/
+    for(uint8_t i = 0; i < 6; i++) {
+        reg_addr_arr[i].value = i * 8;
+    }
+  
+    /*Zero the global index for the TWI*/ 
+    idx = 0;  
+    gy521_update_gyro(m); 
+
+    /*Ensure the correct registers are read*/
+    _Bool is_correct = 1;
+    assert_true(is_correct);
+    for(uint8_t i = 0; i < 6; i++){
+        /*The starting address of the registers is 67 and goes to 72*/ 
+        if((67 + i) != reg_addr_arr[i].addr) {
+            is_correct = 0;
+        }
+    }
+    assert_true(is_correct);     
+
+    /*Check that the values are assembled correctly*/
+    struct gyro_values gyro = gy521_get_gyro(m);
+
+    /*Make sure to bitshift by 8 and recomine the two u8 into a single u16*/
+    assert_true(gyro.x == ((reg_addr_arr[0].value<<8) | reg_addr_arr[1].value));
+    assert_true(gyro.y == ((reg_addr_arr[2].value<<8) | reg_addr_arr[3].value));
+    assert_true(gyro.z == ((reg_addr_arr[4].value<<8) | reg_addr_arr[5].value));
+
+    gy521_free(m);
+}
+
+
+
 
 int main(void)
 {
     const struct CMUnitTest tests[] = {
         cmocka_unit_test(test_gy521_init),
-        cmocka_unit_test(test_gy521_update),
-
+        cmocka_unit_test(test_gy521_update_accel),
+        cmocka_unit_test(test_gy521_update_gyro),
     }; 
     return cmocka_run_group_tests(tests, NULL, NULL);
 }