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by steven1578
Mon Jul 29, 2019 3:56 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

I have pinpointed the issue down to code: Original library code: static inline __attribute__((always_inline)) void softSPITransfer(uint8_t data, volatile port_reg_t *data_port, port_reg_t data_mask, volatile port_reg_t *clk_port, port_reg_t clk_mask) { // Emulate a single byte SPI transfer using sof...
by steven1578
Sun Jul 14, 2019 9:02 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

My experience (in 'C') with 4 x 32x32 modules in series is that you need to put some short delays in to give the data line time to settle before toggling the clock line. // Short delays for bit banging signals. void settleTime(time) { int i; for (i = time; i != 0; --i) { asm(""); // force GCC not t...
by steven1578
Mon Jul 01, 2019 6:34 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

Probaly also...you should first define that a pin should be used as a digital output and then assign a value: void DMD::beginNoTimer() { digitalWrite(pin_clk, LOW); pinMode(pin_clk, OUTPUT); digitalWrite(pin_r_data, LOW); pinMode(pin_r_data, OUTPUT); digitalWrite(pin_noe, LOW); pinMode(pin_noe, OUT...
by steven1578
Mon Jul 01, 2019 6:33 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

My experience (in 'C') with 4 x 32x32 modules in series is that you need to put some short delays in to give the data line time to settle before toggling the clock line. // Short delays for bit banging signals. void settleTime(time) { int i; for (i = time; i != 0; --i) { asm(""); // force GCC not t...
by steven1578
Mon Jul 01, 2019 6:32 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

dsyleixa123 wrote:
Sat Jun 22, 2019 10:41 am
do I undestand you correctly: did it work by Python, even slowly?
If so then I actually doubt that it's a voltage level issue, tbh...
Yes it did, but when I wrote it in Python it was not able (not even close) to render enough frames per second.
by steven1578
Fri Jun 21, 2019 8:48 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

I've not looked into your code but... the Arduino MEGA, if i'm not wrong, works with 5V output levels while the Raspberry works at 3.3V. Could this originate the problem ? Perhaps, with python the code seemed too slow. Maybe combined with the speed of C++ the DMD does not receive enough voltage ind...
by steven1578
Thu Jun 20, 2019 1:17 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

Bumping, I still need help. Anyone has an idea what might be the issue?
by steven1578
Sun Jun 09, 2019 8:46 am
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Re: Weird artifacts on dot matrix display

The problem however is shown in the video: https://www.youtube.com/watch?v=8G8Ydv_b1eE Could you describe what the problem is as, according to youtube, This video is unavailable ? I'm sorry I put it on private instead of hidden. Can you see it now? The problem is that leds that are supposed to be o...
by steven1578
Sat Jun 08, 2019 9:28 pm
Forum: C/C++
Topic: Weird artifacts on dot matrix display
Replies: 14
Views: 1422

Weird artifacts on dot matrix display

Hi guys, I have been trying to make a scoreboard existing of 28 (7x4) P12 dot matrix displays. I have had this same setup running with a arduino mega and it was running just fine however I would like to run it on my pi so that I connect it to the internet easily. I tried using the same library (free...
by steven1578
Mon May 20, 2019 8:11 am
Forum: Beginners
Topic: Programming a P10 DMD (and RPi power issues?)
Replies: 0
Views: 104

Programming a P10 DMD (and RPi power issues?)

Hi guys, So I have been struggling to get my P10 displays to work properly. I have had them running before using a arduino UNO and the DMD library provided by freetronics: https://github.com/freetronics/DMD I have tried porting this library from C to Python and I am using the spidev and RPi.GPIO lib...

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