Library max7219

ricardo · Joined: 11 May 2023 Posts: 1

Hello people, what driver can I use for Max7219, so that the decimal point can be placed in a 7-segment display ? Thank you.

Ttelmah · Joined: 11 Mar 2010 Posts: 19215

Seriously, just talk to it.

It is just an SPI driven LED display. You just send a 16bit word on the SPI
interface, for each digit. This can be sent as BCD, or as raw bit data for
each digit. Addresses 1 to 8 are the seven digits, then address 9 sets
whether these are treated as raw data or BCD. address 10 sets the
intensity. Address 11 sets how many digits it is to scan.
The address is sent in the low 4 bits of the upper byte of the 16bit word.
The data in the low 8bits. Bit D7 is the decimal in both BCD and direct
drive mode.
It is just basic programming. Why do people just not get on and drive things
themselves, rather than assuming someone else will have already done this
basic programming for them?.
It is a matter of probably less than half an hours work to write the code
to control this. The hardest part will be finding what current level your
display wants, which would still have to be done using any 'driver'.

temtronic · Posted: Sun May 14, 2023 5:03 am

Mr T, I call it TTS. Two Thumb Syndrome.
There's an entire generation, or two, that have had the benefit of the Internet and very, very cheap computers (desktop, laptops, smart devices). It seems 'everything' is available on the net..
I doubt that a handful of students,hobbyists or techs have actually wire-wrapped a project or cut assembler,let alone toggle in RIM loaders....
You can build a 'project' from 'modules' these days,or buy what you want premade from China. heck, I needed a simple volt/amp meter to upgrade my 40 year old battery charger. Old school, I'd get a PIC, some resistors, LEDs, do math, maybe etch a PCB, test, modify, then it'd be done. Just bought a complete 'module'. ATMEL based, ground current sensing volts/ammeter with precut wires in a snapin bezel about 1x2" for $2 Canadian ! NO taxes, NO shipping fees, just two dollars (price of a coffee) There's no way I can buy 6 7ssd, micro, support parts, pcb, case for that ! Heck the case alone would be $10 !!

sigh, I'm just a soon to be 70 year old 'dinosaur'.....