xtra1210

STM32F030C8T6 Firmware Created for Epever XTRA1210N MPPT solar charge controller.

This is firmware for MCU STM32F030 (heart of EPEVER solar charge controllers).

WARNING: Author does not respond for possibly destroying Your device! What works:

• charging 24 volts battery using MPPT algorithm
• MPPS algorithm (search over the whole panel load curve for maximum power) once per 5 minutes

What does not work

• load switch
• statistics: consumed energy per day
• store statistics to the flash

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What is slightly implemented:

• cs1621 chip driver for showing segments on XDS1 display
• MODBUS RTU protocol for showing realtime data
• ADC 10 channels in DMA mode
• PWM complementary signal for pseudo-synchronous DC/DC step down converter working on 40kHz

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STM32F030C8T6 pinout description: GPIO in:

• PB14 XDS1 button 1
• PB15 XDS1 button 2
• PB10 output Vpv/Vbat comparator, set if Vbat > Vpv

GPIO out:

• PA8 (FAN7842)[https://www.mouser.com/datasheet/2/149/FAN7842-1006985.pdf] (IR2106 like) Hin (main DC/DC switch IRF100200b2, 100V, 68A, 8.mOhm, 77nC). Passed throuhgt two 74HC132 NANDs
• PB13 (FAN7842)[https://www.mouser.com/datasheet/2/149/FAN7842-1006985.pdf] (IR2106 like) Hlo (synchronous switch IRF100200b2 connected parallel with fast diode). Passed throught two 74HC132 NANDs
• PB1 this enables output of previous two ones using 74HC132 logic
• PB11 red LED on XDS1 display. Active High
• PC13 green LED on XDS1 display. Active Low

ADC in:

• PA0 Vpv, I guess Vpv = x[0]*4962/1000 [100mV];
• PA1 Vbat, I guess Vbat = x[1]*1967/1000 [100mV];
• PA4 V?
• PA2 thermal sensor
• PA3 load current obtained using LMV932
• PA5 battery current obtained using LMV932 (can be negative), I guess Ibat = (x[5]-0x170)*40/100
• PA7 177mV reference (3v3-60k-PA7-3k9-GND)
• PB0 another voltage reference

UART:

• PA10 Rx
• PA9 Tx
• PB9 Rx/Tx switch (low means receive)

SPI (XDS1 driving):

• PB3 nWR (clock)
• PA15 nCR (NSS) must be set by software in this mode
• PB5 data

headers on board:

• PA12 - pin 2 PS1 heade
• PB8 - pin1 P5 header

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HOWTO build this source:

• download STM32CubeMX
• load xtra1210n.ioc from cloned path by git
• select Makefile in ProjectManager->Project->toolchain inside STM32CubeMX
• push GENERATE CODE button
• all necessary files should be shown in your project folder obtained by git
• build using arm-none-eabi-gcc and make
• use J6 pin to connect ST-LINK V2, pins ordered from rectangled pin1 3v3, SWDIO, GND, SWCLK, RST (not needed)
• use stm32-for-vscode plugin, Cortex-debug plugin and openocd to flash compiled code to the solar regulator