tm1637-cuse

Cuse based userland device driver for tm1637 4 or 6 digits displays.

About

The cuse-based driver is an alternative one to a kernel driver tm1637-kmod. It does almost the same as a kernel driver but it does not requires kernel sources to build it, making it easier to use on an Arm PC. For its work a loaded kernel module cuse.ko is required.

Description

Creates a character device on each -d option in a /dev/tm1637/ tree. Each device binded to its own two pins scl and sda. It uses a bit banged manipulation with this pins to transmit data to the tm1637 display connected to them.

You can simply send a string from a shell to the device for output it onto the display bonded to it:

• 12:30;
• 12 30;
• ##:##;
• ## ##;
• 1234;
• 3.14 (If You have a decimal dots type of a display);
• 01.01.21 (If You have a 6 digits display);
• ----;
• .

% echo "1234" > /dev/tm1637/0

It can undestand a command string like:

% printf $"\x80" > /dev/tm1637/0
% printf $"\x8b" > /dev/tm1637/0
% printf $"\x44\xc1\x86" > /dev/tm1637/0
% printf $"\x40\xc0\x06\x86\x06\x06" > /dev/tm1637/0

(See a tm1637 chip datasheet for construct a command string)

Also it support ioctl calls defined in /usr/local/include/tm1637d.h as:

struct tm1637_clock_t {
    int tm_min;
    int tm_hour;
    bool tm_colon;
};

#define TM1637IOC_CLEAR			_IO('T', 1)
#define TM1637IOC_OFF			_IO('T', 2)
#define TM1637IOC_ON			_IO('T', 3)
#define TM1637IOC_SET_BRIGHTNESS	_IOW('T', 11, uint8_t)
#define TM1637IOC_SET_CLOCKPOINT	_IOW('T', 12, uint8_t)
#define TM1637IOC_SET_CLOCK		_IOW('T', 14, struct tm1637_clock_t)

Installation

You do not need a kernel sources for make a cuse-based driver. It is just a daemon You can run as a system service after it is installed.

Clone that git project to ~/src/ directory, change a current directory to the projects new one, build and install the daemon.

% mkdir -p ~/src
% cd ~/src
% git clone https://gitlab.com/alexandermishin13/tm1637-cuse.git
% cd ./tm1637-cuse
% make
% sudo make install

You can wish to copy a file ./rc.conf.d/tm1637d to a directory /usr/local/etc/rc.conf.d/tm1637/ and change it to suit Your needs. Then load a system module cuse.ko and run the service:

% kldload cuse
% service tm1637d start

You can add the following line to the file /boot/loader.conf in order for the module to load automatically at system startup:

cuse_load="YES"

One or more devices will be created into /dev/tm1637/ directory. You can change permits to them by change a file /etc/devfs.rules and restart a devfs service. Read about how to do it:

% man 5 devfs.rules

Status

Time tested and found ready to use.