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![Raspberry Pi code example #Python import RPi.GPIO as GPIO import time def main(): # Main program block GPIO.setmode(GPIO.BCM) # GPIO.setup(LCD_E, GPIO.OUT) # E GPIO.setup(LCD_RS, GPIO.OUT) # RS GPIO.setup(LCD_D4, GPIO.OUT) # DB4 GPIO.setup(LCD_D5, GPIO.OUT) # DB5 GPIO.setup(LCD_D6, GPIO.OUT) # DB6 GPIO.setup(LCD_D7, GPIO.OUT) # DB7 #etc… def lcd_byte(bits, mode): # Send byte to data pins # bits = data # mode = True for character # False for command GPIO.output(LCD_RS, mode) # RS # High bits GPIO.output(LCD_D4, False) GPIO.output(LCD_D5, False) GPIO.output(LCD_D6, False) GPIO.output(LCD_D7, False) #etc… //C int mcp3008Spi::spiOpen(std::string devspi){ int statusVal = -1; this->spifd = open(devspi.c_str(), O_RDWR); if(this->spifd < 0){ perror("could not open SPI device"); exit(1); } statusVal = ioctl (this->spifd, SPI_IOC_WR_MODE, &(this->mode)); if(statusVal < 0){ perror("Could not set SPIMode (WR)...ioctl fail"); exit(1); } //etc… // Transfer data with SPI: one spi transfer for each byte for (i = 0 ; i < length ; i++){ spi[i].tx_buf = (unsigned long)(data + i); // transmit from "data" spi[i].rx_buf = (unsigned long)(data + i) ; // receive into "data" spi[i].len = sizeof(*(data + i)) ; spi[i].delay_usecs = 0 ; spi[i].speed_hz = this->speed ; spi[i].bits_per_word = this->bitsPerWord ; spi[i].cs_change = 0; } retVal = ioctl (this->spifd, SPI_IOC_MESSAGE(length), &spi) ;](https://image.slidesharecdn.com/armdevboardspdf-150712083313-lva1-app6892/75/Using-ARM-Dev-Board-in-physical-experimental-instruments-11-2048.jpg)
Using ARM Dev.Board in physical experimental instruments
- 1. Using ARM Dev.Board inphysical experimental instruments IoT 2015 Bar Montenegro Andrey Novikov, msc-cg
- 2. mass spectrometry Sector MS(1936) Time of Flight MS (1948) Quadrupole (1970) deflection
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- 6. What we hadbefore • static voltages on lenses • FTDI USB-I2C bus • 2-20ms per command • 1-2% of lost commands • update frequency 5-10Hz
- 7. Requested Specification • ChangeVoltage 2-4 channels every 10-20us (precision 16bit 0.1mV/10V) • Measure 1 Voltage (16-24bit) channel on each step. • measured data samples without time gaps for 1s (100000 samples on that frequency) • transfer all acquired data less then 10ms to the PC. • be ready for new cycle. • should be easily scalable
- 8. Interfaces microcontroller layer digitalInterfaces • GPIO - General Purpose Input Output • SPI - Serial Peripheral Interface • I2C(TWI) - two ware interface PC layer connection data transfer interface • Ethernet 10/100Mb • RS-232 • RS-485
- 9. Development Boards • RaspberryPi • Arduino • ST32F • STM discovery dev board • Mountaineer • OLIMEX
- 10. Raspberry Pi-2 A 900MHzquad-core ARM Cortex-A7 1GB RAM 4 USB ports 40 GPIO pins Full HDMI port Ethernet port 10/100 Combined 3.5mm audio jack and composite video Camera interface (CSI) Display interface (DSI) Micro SD card slot VideoCore IV 3D graphics core Linux Distros: • Rasbian (Debian) • Pidora(Fedora) • Arch Linux (Pi build) • Ubuntu 14 (for Pi2)
- 11. Raspberry Pi codeexample #Python import RPi.GPIO as GPIO import time def main(): # Main program block GPIO.setmode(GPIO.BCM) # GPIO.setup(LCD_E, GPIO.OUT) # E GPIO.setup(LCD_RS, GPIO.OUT) # RS GPIO.setup(LCD_D4, GPIO.OUT) # DB4 GPIO.setup(LCD_D5, GPIO.OUT) # DB5 GPIO.setup(LCD_D6, GPIO.OUT) # DB6 GPIO.setup(LCD_D7, GPIO.OUT) # DB7 #etc… def lcd_byte(bits, mode): # Send byte to data pins # bits = data # mode = True for character # False for command GPIO.output(LCD_RS, mode) # RS # High bits GPIO.output(LCD_D4, False) GPIO.output(LCD_D5, False) GPIO.output(LCD_D6, False) GPIO.output(LCD_D7, False) #etc… //C int mcp3008Spi::spiOpen(std::string devspi){ int statusVal = -1; this->spifd = open(devspi.c_str(), O_RDWR); if(this->spifd < 0){ perror("could not open SPI device"); exit(1); } statusVal = ioctl (this->spifd, SPI_IOC_WR_MODE, &(this->mode)); if(statusVal < 0){ perror("Could not set SPIMode (WR)...ioctl fail"); exit(1); } //etc… // Transfer data with SPI: one spi transfer for each byte for (i = 0 ; i < length ; i++){ spi[i].tx_buf = (unsigned long)(data + i); // transmit from "data" spi[i].rx_buf = (unsigned long)(data + i) ; // receive into "data" spi[i].len = sizeof(*(data + i)) ; spi[i].delay_usecs = 0 ; spi[i].speed_hz = this->speed ; spi[i].bits_per_word = this->bitsPerWord ; spi[i].cs_change = 0; } retVal = ioctl (this->spifd, SPI_IOC_MESSAGE(length), &spi) ;
- 12. using RPi? Linux DataServer/Desktop • Pros • low power consumption • small size • full functional Linux • Cons • SD rewrite limit Linux Dev.Board • Pros • self-sufficiency • scalable • SPI & I2C present on board • Cons • few digital interface ports • on linux kernel delay 100us ChibiOs or RTOS Dev.Board
- 13. Arduino Arduino Uno Microcontroller ATmega3288-bit AVR RISC-based 20MHz I2C x1 SPI x2 UART x1 ADC: 8ch 10bit 15kbps Arduino Uno with Eth shield
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- 15. STM32F407 STM407 Discovery Board withExtension Board ST-Link Mountaineer NETMF .NET BootLoader OLIMEX STM32-E407 USB-DFU Bootloader
- 16. IDE • Keil http://www.keil.com •CooCox CoIDE http://www.coocox.org • .NET MicroFramework http://www.netmf.com • Arduino IDE https://www.arduino.cc/en/Main/ Software • GNU C Compiler
- 17. STM SDK Open SourceSDK includes: • Easy to use and well documented periphery functions. GPIO, I2C, SPI • Very difficult to use(based on callbacks) LwIP library - so sth-stack in STM is a pain • RTOS library: • have tcp-ip socket • but task scheduler some times freezes all tasks up to 10ms • it’s “ortodox” Ansi C 99
- 18. STM32F4Cube Resolving Pin Conflict GeneratingPin Report Template Projects: • EWARM • MDK-ARM V4 • MDK-ARM V5 • TrueStudio • SW4STM32
- 19. Prototype 1 based onstm32f407 discovery DAC: AD5544 4ch 16bit ADC: TLC4541 1ch 16bit ETH+Disp: Discovery Ext.Board IDE: Keil v4.74 time spent: programmer: 4 weeks electronics engineer: 2 weeks time spent: programmer: 4 weeks electronics engineer: 2 weeks time spent: programmer: 4 weeks electronics engineer: 2 weeks
- 20. Prototype 2 (failed) DAC:AD5668 8ch 16bit ADC: AD7606 8ch 16bit ETH: LAN8720 acid etched PCB didn’t worked correctly because of huge amount of breakthroughs, but SW algorithms worked through time spent: programmer: 4-6 weeks electronics engineer: 2-3 weeks
- 21. Pre-Release • 8x PairedADC-DAC • 5us update time • 1ms command response time • approved 100MB transfer speed • ETH-I2C bus translator DAC: AD5668 8ch 16bit ADC: ADAS3023 8ch 16bit ETH: LAN8720 two side factory printed PCB
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- 23. In Plans • usingindividual 18-24bit ADC for signal registration • adding eth-events handler to sync state between stm units • combine Real-Time STM units and RaspberryPi2 as a central control node under Linux • DDA - Data Dependent Acquisition • finish “home dark-server” based on RPi-2
- 24. Conclusions Modern Microelectronics is: •Easy to understand (entrance threshold is very low) • Easy scale (a lot of standard interfaces that you can just use) • easy to buy (cheap and wide choice) • really fun and interesting