minipill_lora_board_platformio/README.md

# MiniPill LoRa Board
Here is general information on the (PlatformIO) settings for the MiniPill 
LoRa boards. The files on this repository are placed in ~/.platformio. 
Where ~/ is your home directory. 

These settings are used on macOS platforms with user leo.
Please changes the files for your OS/user.

## version 2022-12-24
Created develop branch where other boards with other microcontrollers are 
available and tested. Removed them from main branch. Only the 
STM32L051C8T6 and STM32L151C8T6 version is present at the main branch.

## versions 2022-10-23
- ```PlatformIO Core, version 6.1.4```
- Initial setup of this repository
- Removed board information from MiniPill LoRa LMIC project and moved to 
this repository

## Board versions
There are different version available 1.x, 2.x, 3.x. All versions use the 
same electronic schematic. Only the PCB layout and/or antenna connector is 
different. 

## Two types of processors supported
In the boards directory are a two major types and some test boards, please 
ignore them.

The Orginal MiniPill LoRa with STM32L051C8T6

```minipill_l051c8_lora.json``` variant dir: ```MINIPILL_L051XX_LORA```

For testing with STM32L151C8T6

```minipill_l151c8_lora.json``` variant dir: ```MINIPILL_L151XX_LORA```


## Adding a custom board in PlatformIO
To work with the MiniPill LoRa in more than one project you should add 
this custom board to you PlatformIO toolset.
On MacOS under the user's homedirectory a .platformio directory is 
available for the toolsets. This is the platformio homedirectory. Please 
check for your OS where this directory is located.

- copy the *boards* and *variants* directory from customboard directory to 
the ```.platformio``` directory
- change the absolute path in the boards/minipill_l051c8_lora.json file 
for the variants path
- restart platformio/IDE

Now you should be able to use the MiniPill LoRa board in a new project.
Not all functions are tested with this custom board configurations.

## debugging
I use the hardwareSerial for debugging and connected a serial TTL-USB 
converter. This will take some power in Low Power mode.

## Clock Settings
The clock settings for this custom board are set in the
`.platformio/variants/MINIPILL_L051XX_LORA/variant.cpp` file. In the `WEAK 
void SystemClock_Config(void)` function the HAL functions are called to 
select the clocks.
For use of I2C and 100kHz clock signal you have to change these settings 
in:

```
	WEAK void SystemClock_Config(void)
	{
	  RCC_OscInitTypeDef RCC_OscInitStruct = {};
	  RCC_ClkInitTypeDef RCC_ClkInitStruct = {};
	  RCC_PeriphCLKInitTypeDef PeriphClkInit = {};

	  /* Configure the main internal regulator output voltage */
	  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

	  /* Initializes the CPU, AHB and APB busses clocks */
	  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
	  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
	  RCC_OscInitStruct.MSICalibrationValue = 0;
	  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_5;
	  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
	  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
	    Error_Handler();
	  }

	  /* Initializes the CPU, AHB and APB busses clocks  */
	  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | 
RCC_CLOCKTYPE_SYSCLK
	                                | RCC_CLOCKTYPE_PCLK1 | 
RCC_CLOCKTYPE_PCLK2;
	  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
	  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
	  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
	  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

	  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != 
HAL_OK) {
	    Error_Handler();
	  }
	  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1 | 
RCC_PERIPHCLK_USART2
	                                       | RCC_PERIPHCLK_I2C1;
	  PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
	  PeriphClkInit.Usart2ClockSelection = RCC_USART2CLKSOURCE_PCLK1;
	  PeriphClkInit.I2c1ClockSelection = RCC_I2C1CLKSOURCE_PCLK1;
	  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) {
	    Error_Handler();
	  }
	}
```

You can also **add this function to you main code** and call it in the 
first line of the setup function of your Arduino main program. Do not use 
the WEAK compiler direction.

When you must use a higher clock rate you should use the HSI clock. In my 
experience this is necessary when using OLED displays with I2C 
communication.

The function for 400kHz clock rate is:

```
	void SystemClock_Config(void)
	{
	  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
	  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
	  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};

	  /** Configure the main internal regulator output voltage
	  */
	  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
	  /** Initializes the RCC Oscillators according to the specified 
parameters
	  * in the RCC_OscInitTypeDef structure.
	  */
	  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
	  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
	  RCC_OscInitStruct.HSICalibrationValue = 
RCC_HSICALIBRATION_DEFAULT;
	  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
	  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
	  {
	    Error_Handler();
	  }
	  /** Initializes the CPU, AHB and APB buses clocks
	  */
	  RCC_ClkInitStruct.ClockType = 
RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
	                              
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
	  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
	  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV8;
	  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
	  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

	  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != 
HAL_OK)
	  {
	    Error_Handler();
	  }
	  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_I2C1;
	  PeriphClkInit.I2c1ClockSelection = RCC_I2C1CLKSOURCE_HSI;
	  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
	  {
	    Error_Handler();
	  }
	}
```

Remember that the change in clock settings will affect power consumption! 
You can generate you own clock settings by using STM32CubeMX or 
STM32CubeMXIDE configurator. Copy the `SystemClock_Config(void)` function 
generated by the configurator.