CN206906855U - A kind of I/O port expanded circuit based on STM32F7 - Google Patents

Abstract

The utility model discloses a kind of I/O port expanded circuit based on STM32F7, including extending mouth chip, extension mouth chip selects model PCF8574/AT8574, realize that STM32F7 2 I/O ports expand to 8 I/O ports by PCF8574/AT8574, and can meet 8 PCF8574 with Parallel Control, most 2 I/O ports, 64 I/O ports can be extended, open-drain interrupt output is realized, effectively solves the problems, such as that single-chip I/O mouth is inadequate in circuit design process, greatly saves hardware cost；Secondly, USB PWR are in series with extension mouth chip, can perfectly be realized to development board USB_HOST interfaces, nine axle sensors and the control of luminous environment detection sensor, support interrupt output and relatively low operating voltage, compatible main flow 3.3V and 5V single-chip microcomputer operation IO.

Description

A kind of I/O port expanded circuit based on STM32F7

Technical field

It the utility model is related to chip interface expansion technique field, specially a kind of I/O port extension electricity based on STM32F7 Road.

Background technology

Because STM32F7 chip dominant frequency high performance-price ratio is high, current numerous technical schemes using ARM9 have steering to use Trend of the STM32F7 as main control unit.But because STM32F7 could support up 218 pins, the STM32F7 of main flow at present Chip only supports 176 pins, and wherein universal I/O port is less than 150.This system big to I/O port demand just can not normally make With.In order to solve the problems, such as that STM32F7 I/O port is not enough, STM32F7 I/O port expanded circuit research and development are arisen at the historic moment.

Utility model content

The purpose of this utility model is to provide a kind of I/O port expanded circuit based on STM32F7 effectively solve circuit and set The problem of single-chip I/O mouth is inadequate during meter, hardware cost is greatly saved, to solve what is be previously mentioned in above-mentioned background technology Problem.

To achieve the above object, the utility model provides following technical scheme：A kind of I/O port extension electricity based on STM32F7 Road, including extension mouth chip, No. 8 pins output ground connection of VSS ends series connection of the extension mouth chip, its A0 end, A1 ends and A2 ends By No. 1 pin, No. 2 pins and No. 3 pins in parallel output ground connection, the corresponding No. 4 pins output in P0 ends connects exchange agreement interface BEEP；The corresponding No. 5 pins input in P1 ends of the extension mouth chip is connected to wired network interface AP, wired network interface AP input End is in series with 10K resistance R45, resistance R45 other ends connection power supply VCC；The P2 ends of the extension mouth chip and P3 ends difference By No. 6 pins, No. 7 pin serial connection digital picture interface DCMI and USB translation interfaces, between No. 7 pins and USB translation interfaces Also it is parallel with 1K resistance R51, resistance R51 input series-connection power supplies VCC；Drawn by No. 9 at the P4 ends of the extension mouth chip Pin meets EXIO translation interfaces, the other end series connection 10K of EXIO translation interfaces resistance R52；The P5 ends of the extension mouth chip lead to Cross No. 10 pins and connect 9D interfaces, the resistance R50 for the 10K that connected on 9D interfaces；The P6 ends of the extension mouth chip pass through No. 11 pins Communication interface RS485 is connected, its P7 end passes through No. 12 pin serial connection 4.7K resistance R46, resistance R46 input parallel connection 1K electricity R48 is hindered, resistance R46 output end is in series with triode Q1 basis set, triode Q1 grounded emitter, and colelctor electrode is parallel with drive Mobile interface ETH RESET and 4.7K resistance R44, resistance R44 other end series-connection power supplies VCC；The INT of the extension mouth chip End, SCL ends, corresponding 13,14, No. 15 corresponding interfaces of pin serial connection in SDA ends, the corresponding No. 16 pin serial connection electric capacity of its vdd terminal C57, electric capacity C57 one end parallel connection power supply VCC, other end series connection ground connection.

Preferably, the resistance R48, resistance R50 and resistance R52 input are parallel with power supply VCC.

Preferably, the input voltage range of the power supply VCC is in 2.5V-6.0V, i.e., 3.3V the and 5V monolithics of compatible main flow Machine operates IO.

Preferably, the model PCF8574/AT8574 of the extension mouth chip, is realized by PCF8574/AT8574 STM32F7 2 I/O ports expand to 8 I/O ports, and can be with Parallel Control.

Compared with prior art, the beneficial effects of the utility model are as follows：

1st, the I/O port expanded circuit of the present utility model based on STM32F7, passes through the extension of PCF8574/AT8574 models Mouthful chip 1 realizes STM32F7 I/O port extension, realizes that 2 I/O ports expand to 8 I/O ports, and can be with Parallel Control, most 2 I/O port can meet 8 PCF8574, can extend 64 I/O ports, realize open-drain interrupt output, effectively solve in circuit design process The problem of single-chip I/O mouth is inadequate, greatly save hardware cost.

2nd, the I/O port expanded circuit of the present utility model based on STM32F7, can perfectly be realized to development board USB_ HOST interfaces, nine axle sensors and the control of luminous environment detection sensor, support interrupt output and relatively low operating voltage, compatible Main flow 3.3V and 5V single-chip microcomputer operation IO.

Brief description of the drawings

Fig. 1 is the utility model circuit theory diagrams.

In figure：1- extends mouth chip.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made The every other embodiment obtained, belong to the scope of the utility model protection.

Referring to Fig. 1, a kind of I/O port expanded circuit based on STM32F7, including extension mouth chip 1, extension mouth chip 1 Model PCF8574/AT8574,2 I/O ports for realizing STM32F7 by PCF8574/AT8574 expand to 8 I/O ports, and can With Parallel Control；No. 8 pins output ground connection of VSS ends series connection of mouth chip 1 are extended, its A0 end, A1 ends and A2 ends are drawn by No. 1 Pin, No. 2 pins and No. 3 pins in parallel output ground connection, the corresponding No. 4 pins output in P0 ends meet exchange agreement interface BEEP；Extend mouth The corresponding No. 5 pins input in the P1 ends of chip 1 is connected to wired network interface AP, and wired network interface AP input is in series with 10K's Resistance R45, resistance the R45 other end connection power supply VCC；The P2 ends and P3 ends of extension mouth chip 1 are drawn by No. 6 pins, No. 7 respectively The digital image interface DCMI of pin series connection and USB translation interfaces, 1K resistance is also parallel between No. 7 pins and USB translation interfaces R51, resistance R51 input series-connection power supplies VCC, are realized to development board USB_HOST interfaces, nine axle sensors and luminous environment Detection sensor controls；The P4 ends of extension mouth chip 1 connect EXIO translation interfaces by No. 9 pins, EXIO translation interfaces it is another End series connection 10K resistance R52；The P5 ends of extension mouth chip 1 connect 9D interfaces by No. 10 pins, the electricity for the 10K that connected on 9D interfaces Hinder R50；Communication interface RS485 is connected in the P6 ends for extending mouth chip 1 by No. 11 pins, and its P7 end passes through No. 12 pin serial connection 4.7K Resistance R46, resistance R46 input parallel connection 1K resistance R48, resistance R48, resistance R50 and resistance R52 input is in parallel There is power supply VCC；Resistance R46 output end is in series with triode Q1 basis set, triode Q1 grounded emitter, colelctor electrode parallel connection There are driving interface ETH RESET and 4.7K resistance R44, resistance R44 other end series-connection power supplies VCC；Extend mouth chip 1 INT ends, SCL ends, corresponding 13,14, No. 15 corresponding interfaces of pin serial connection in SDA ends, the corresponding No. 16 pin serial connection electric capacity of its vdd terminal C57, electric capacity C57 one end parallel connection power supply VCC, other end series connection ground connection, power supply VCC input voltage range in 2.5V-6.0V, 3.3V the and 5V single-chip microcomputers operation IO of i.e. compatible main flow.

In summary：Based on STM32F7 I/O port expanded circuit, pass through the extension mouth core of PCF8574/AT8574 models Piece 1 realizes STM32F7 I/O port extension, realizes that 2 I/O ports expand to 8 I/O ports, and can be with Parallel Control, most 2 I/O ports 8 PCF8574 can be met, 64 I/O ports can be extended, realize open-drain interrupt output, effectively solve monolithic in circuit design process The problem of machine I/O port is inadequate, greatly saves hardware cost；Secondly, the I/O port expanded circuit can be realized perfectly to development board USB_HOST interfaces, nine axle sensors and the control of luminous environment detection sensor, support relatively low operating voltage, compatible main flow 3.3V and 5V single-chip microcomputer operation IO.

While there has been shown and described that embodiment of the present utility model, for the ordinary skill in the art, It is appreciated that these embodiments can be carried out with a variety of changes in the case where not departing from principle of the present utility model and spirit, repaiied Change, replace and modification, the scope of the utility model are defined by the appended claims and the equivalents thereof.

Claims (4)

1. a kind of I/O port expanded circuit based on STM32F7, including extension mouth chip (1), it is characterised in that：The extension mouth core No. 8 pins output ground connection of VSS ends series connection of piece (1), its A0 end, A1 ends and A2 ends pass through No. 1 pin, No. 2 pins and No. 3 pins Parallel opertation is grounded, and the corresponding No. 4 pins output in P0 ends meets exchange agreement interface BEEP；The P1 ends pair of the extension mouth chip (1) No. 5 pin inputs are answered to be connected to wired network interface AP, wired network interface AP input is in series with 10K resistance R45, resistance R45 other ends connection power supply VCC；The P2 ends and P3 ends of the extension mouth chip (1) pass through No. 6 pins, No. 7 pin serial connections respectively Digital picture interface DCMI and USB translation interface, 1K resistance R51 is also parallel between No. 7 pins and USB translation interfaces, electricity Hinder R51 input series-connection power supplies VCC；The P4 ends of the extension mouth chip (1) connect EXIO translation interfaces by No. 9 pins, The other end series connection 10K of EXIO translation interfaces resistance R52；The P5 ends of the extension mouth chip (1) meet 9D by No. 10 pins Interface, the resistance R50 for the 10K that connects on 9D interfaces；Communication interface is connected in the P6 ends of the extension mouth chip (1) by No. 11 pins RS485, its P7 end pass through No. 12 pin serial connection 4.7K resistance R46, resistance R46 input parallel connection 1K resistance R48, resistance R46 output end is in series with triode Q1 basis set, triode Q1 grounded emitter, and colelctor electrode is parallel with driving interface ETH RESET and 4.7K resistance R44, resistance R44 other end series-connection power supplies VCC；The INT ends of the extension mouth chip (1), SCL End, corresponding 13,14, No. 15 corresponding interfaces of pin serial connection in SDA ends, the corresponding No. 16 pin serial connection electric capacity C57 of its vdd terminal, electric capacity C57 one end parallel connection power supply VCC, other end series connection ground connection.

A kind of 2. I/O port expanded circuit based on STM32F7 according to claim 1, it is characterised in that：The resistance R48, resistance R50 and resistance R52 input are parallel with power supply VCC.

A kind of 3. I/O port expanded circuit based on STM32F7 according to claim 1 or 2, it is characterised in that：The power supply VCC input voltage range is in 2.5V-6.0V, i.e., 3.3V the and 5V single-chip microcomputers operation IO of compatible main flow.

A kind of 4. I/O port expanded circuit based on STM32F7 according to claim 1, it is characterised in that：The extension mouth The model PCF8574/AT8574 of chip (1), 2 I/O ports for realizing STM32F7 by PCF8574/AT8574 expand to 8 I/O port, and can be with Parallel Control.