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Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Wed Feb 20, 2019 10:01 am
by andrew
They're not actually our product, we're just a re-seller for them. But I see your point about the headers - would make more sense for them to be fitted on the reverse side. I'll feed it back to the manufacturer when the opportunity arises.
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Wed Feb 20, 2019 1:48 pm
by Phil-S
Thanks for that.
I had guessed they were bought in.
They're quite good quality PCB-wise.
I have managed to de-solder all the headers and display sockets. The displays are soldered straight in now and are a little tidier. I reversed the male headers and added offset (0.05") pins to bring them into line with 0.1" perfboard.
With the Nano onboard, it makes quite a useful counter, even at very fast count rates.
For what it's worth, I always use the StateChange example from the Arduino IDE to process button or digital changes. Of all the examples, this one seems the most reliable
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Thu Jun 27, 2019 12:07 am
by Mini
Hi,
Please, where can I find a drawing with precise dimensions including the PCB holes diameters and positions?
I'm asking because I would like to request a quote for laser cutting an acrylic mask.
(Or in some fireproof material... no idea yet if they offer any such alternatives.)
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Wed Jan 26, 2022 3:47 pm
by JSByron
Dear all,
What size are the supplied bolts/pillars for panel mounting, please?
Thank you.
James.
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Thu Jan 27, 2022 9:56 am
by andrew
The screws and pillars are M3. The pillars are 6mm in height with a 5mm diameter.
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Mon Apr 11, 2022 2:33 pm
by DennisJ
Hi
I have just purchased two MAX7219 7 segment LEDS displays (from Hobby Components via Amazon) and whilst I can get them working on their own with your HCMAX7219 library, I cannot seem to get them working in tandem. I have changed the NUMBEROFDRIVERS to 2 in HCMAX7219.h, changed the line HCMAX7219.print7Seg("1234567-1234567-",16); to 16 (appears to need this as the buffer), but still nothing on the second display. Checked and double checked wiring. Both work ok on their own, but neither work in postion B.
Connected them through other libaries, same problem. Connected them direct to Mobiflight (the actual purpose) and nothing appears on the second display, even under Test. Again, work individually, and always the second display not working when swapped position.
Am i doing something wrong - or could there be a fault on the boards - I'm thinking 'both' boards - unlikely. Does it need some external resistors/ caps? Im driving through an Elegoo UNO R3.
Den
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Tue Apr 12, 2022 8:23 am
by andrew
whilst I can get them working on their own with your HCMAX7219 library, I cannot seem to get them working in tandem.
Both work ok on their own, but neither work in postion B.
Am i doing something wrong - or could there be a fault on the boards - I'm thinking 'both' boards - unlikely. Does it need some external resistors/ caps? Im driving through an Elegoo UNO R3.
The only potential issue when connecting more than one module together is that they have diodes in series with the 5V supply for reverse polarity protection. This causes a small volt drop at the 5V output of each module. So when connecting multiple modules the diodes need to be shorted out. That said though, although it would explain your issue, connecting two shouldn't be a problem as long as you have a good 5V supply and short cables.
Just to sanity check the software could you give this sketch a try. It should display 12345678 on the first module and 87654321 on the second (with NUMBEROFDRIVERS set to 2)...
#include <HCMAX7219.h>
#include "SPI.h"
#define LOAD 10
HCMAX7219 HCMAX7219(LOAD);
void setup()
{
HCMAX7219.Init();
}
void loop()
{
HCMAX7219.Clear();
HCMAX7219.print7Seg("1234567887654321",16);
HCMAX7219.Refresh();
while(1);
}
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Tue Apr 12, 2022 8:43 am
by DennisJ
Thanks for the fast response
I'm getting a compile error as follows:
Arduino: 1.8.19 (Windows 10), Board: "Arduino Nano, ATmega328P (Old Bootloader)"
C:\Users\xxxx\Documents\Arduino\sketch_apr12a\sketch_apr12a.ino: In function 'void setup()':
sketch_apr12a:11:22: error: 'void HCMAX7219::Init()' is private within this context
HCMAX7219.Init();
(Note, this is now being tested on a Nano board, but same issue)
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Tue Apr 12, 2022 9:25 am
by andrew
It seems to be compiling fine for me. Can you check that you have V0.5 of the library. You can find the version you have at the top of the .h and .cpp files.
If so then try downloading the library again (link to latest:
download/file.php?id=558). You can just copy the .h and .cpp files into your current \libraries\HCMAX7219 folder but remember to change the NUMBEROFDRIVERS back to 2 again.
Re: MAX7219 8 Digit Seven Segment Display Module (HCMODU0082)
Posted: Tue Apr 12, 2022 10:47 am
by DennisJ
Apologies, I didnt have the latest library.
All compiled, loaded to board and same issue.
I note that once loaded, if I press the boards reset button, the second display flashes all segments momentarily, but blanks and leaves nothing on the display.
I've gone back to the UNO board as the Nano is new to me and best to stay with the original issue, although neither results in anything on the second display.