The Snickerdoodle Book/PlatformController
Contents
Platform Controller
Introduction
Snickerdoodle's platform controller is a STM32F0 series 32-bit ARM®Cortex-A0® microcontroller connected to and in control of various signals. See "Chapter 9" for a bit of an introduction.
15. Peripherals
ADC
Several 12-bit analog to digital converters (ADC) on the platform controller are used to monitor the on-board systems. The power supply levels are monitored using the ADCs.
TODO: insert Table 15.1: ADC Port Connection
I2C
SPI
LEDs
The platform controller is connected to 5 LEDs that are used to indicate various states and events of the board. These LEDs are connected to peripherals that are configured as PWM timers for brightness control on the LEDs through the PWM duty cycle.
| PA8 | D11 | TIM1 CH1 | Red (fault) |
| PC6 | E12 | TIM3 CH1 | Green (USB/Power) |
| PC7 | E11 | TIM3 CH2 | Blue (Bluetooth) |
| PC8 | E10 | TIM3 CH3 | White (Application) |
| PC9 | D12 | TIM3 CH4 | Orange (Wireless Link) |
USART
USART1
USART1 is connected to the Zynq processing subsystem on UART0 and is normally used to bridge the Zynq console output to the USB device peripheral. Normally the USB device is configured as a communications device class (CDC) interface.
| Mode | Asynchronous |
|---|---|
| Hardware Flow Control (RS-232) | Disabled |
| Baud Rate | 115200 |
| Word Length | 8 bits |
| Parity | None |
| Stop Bits | 1 |
| Data Direction | Receive and Transmit |
| Over Sampling | 16 Samples |
| Single Sample | Disable |
USART2
USART2 is connected to the Bluetooth HCI interface of the Wilink 8 module.
TODO: insert Table 15.4: Platform Controller USART2
USB Device
The USB device peripheral is normally configured as a communications device class (CDC) interface to provide access to the Zynq console by bridging to USART1 which is connected to UART0 on the Zynq.
During certain boot modes, the USB device is configured for device firmware upgrade (DFU) and can be used to program the platform controller by writing directly to the embedded flash memory.
Basic Parameters
TODO: insert Table 15.5: USB Parameters
GPIO
| STM32 Port Pin | Zynq Pin | I/O | Description |
|---|---|---|---|
| PA9 | D10 | Output | ANT_SELECT_1 |
| PA10 | C12 | Output | ANT_SELECT_2 |
| PC1 | J2 | Output | ZYNQ_JTAG_NRST |
| PD1 | B9 | Output | ZYNQ_POWER_EN |
| PD2 | C8 | Output | WDI |
| PD7 | A5 | Output | WL_32KHZ_CLK_EN |
| PD8 | K9 | Output | ZYNQ_CLK_EN |
| PE2 | B2 | Output | MIO4_BOOT_SELECT |
| PE3 | A1 | Output | MIO5_BOOT_SELECT |
| PE4 | B1 | Input | SELECT_BUTTON |
| PE5 | C2 | Input | RESET_BUTTON |
| PE7 | M7 | Input | ZYNQ_POWER_GOOD |
| PF10 | G2 | Output | WL18xx_BT_EN |
| PD15 | H10 | Output | SMB_NRESET |
EXTI
| STM32 Port Pin | Zynq Pin | I/O | Description |
|---|---|---|---|
| PD10 | J12 | EXTI10 | JA1_P2 |
| PD11 | J11 | EXTI11 | JA2_P2 |
| PD12 | J10 | EXTI12 | JB1_P2 |
| PD13 | H12 | EXTI13 | JB2_P2 |
| PD14 | H11 | EXTI14 | JC1_P2 |
16. Firmware
The platform controller firmware provides the logic for handling the tasks of the...
Development Environment
The integrated development environment used to target the platform controller is the ARM® Keil microcontroller development kit (MDK). The MDK can be downloaded from http://www2.keil.com/stmicroelectronics-stm32/ mdk. After registering and activating the MDK, custom platform controller firmware can be developed and compiled
17. Device Firmware Upgrade (DFU)
For full customization of the Snickerdoodle system the firmware on the platform controller can be modified and upgraded.
For more details see Chapter 17 here.
18. USB Interface (Virtual COM Port)
The USB interface is most commonly specified as a communications class device and used to bridge the UART (RS-232) connection between the platform controller and the application processor.
For more details see Chapter 18 here.
